CN117385886A - Construction method of medical house radiation-proof concrete structure - Google Patents

Construction method of medical house radiation-proof concrete structure Download PDF

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Publication number
CN117385886A
CN117385886A CN202311275280.2A CN202311275280A CN117385886A CN 117385886 A CN117385886 A CN 117385886A CN 202311275280 A CN202311275280 A CN 202311275280A CN 117385886 A CN117385886 A CN 117385886A
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China
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concrete
wall
temperature
pouring
construction
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杨义松
陈瑞
陈琳
叶华
庞洪海
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Shanghai Baoye Construction Engineering Co ltd
Shanghai Baoye Group Corp Ltd
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Shanghai Baoye Construction Engineering Co ltd
Shanghai Baoye Group Corp Ltd
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Priority to CN202311275280.2A priority Critical patent/CN117385886A/en
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    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D15/00Handling building or like materials for hydraulic engineering or foundations
    • E02D15/02Handling of bulk concrete specially for foundation or hydraulic engineering purposes
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D29/00Independent underground or underwater structures; Retaining walls
    • E02D29/045Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)

Abstract

The invention relates to a construction method of a radiation-proof concrete structure of a medical house, which comprises the following two parts: a first part: and (3) foundation slab structure construction: the method comprises the steps of earth excavation, concrete cushion layer, waterproof and protective layer, baseboard reinforcement binding, embedded part, baseboard concrete pouring and baseboard concrete maintenance; a second part: construction of a wall and roof structure: the method comprises the steps of binding wall steel bars, installing embedded parts in the wall, checking and accepting, installing wall templates, installing opposite-pull screws for reinforcing templates, erecting a support frame, installing a top plate template, binding plate steel bars, installing the embedded parts, checking and accepting, casting the wall, and maintaining the top plate concrete. The invention provides a set of completed construction method for the subsequent medical radiation-proof structural engineering and similar structural engineering construction.

Description

Construction method of medical house radiation-proof concrete structure
Technical Field
The invention relates to the field of construction of constructional engineering, in particular to a construction method of a radiation-proof concrete structure of a medical house.
Background
The construction is a large medical comprehensive building, and has a plurality of rooms for medical functions, wherein a linear accelerator machine room positioned at two layers of a project basement is used as a heavy difficult room for project construction, the excavation depth of a foundation pit is 12 meters, the north side of the structure is close to a supporting pile base, the impervious grade of the structure is P8, the structure is an ultra-thick large-volume concrete structure, the wall is up to 3000mm, the top plate is up to 2500mm, the internal space channel is narrow and the whole body is arc-shaped, so that the construction process control of the large-volume concrete anti-cracking technology, the reinforcement engineering, the structural template engineering, the concrete pouring engineering and the concrete forming protection of the room structure for functions is very important, and the invention also mainly solves the quality safety control problem.
Compared with the conventional concrete structure engineering, the reinforced steel bar, the template and the concrete engineering are simpler, the structural beam slab wall body is small in section, thin in thickness, small in height and square in space modeling, the reinforced steel bar is small in specification, the concrete is thin in thickness, the template support can be a conventional steel pipe fastener system, the reinforcement is simple due to few factors to be considered, meanwhile, the frame body is convenient and quick to arrange, and the quality control of the concrete is simpler.
For the concrete building with the ultra-thick arc curved surface and high quality requirement, the traditional construction method is adopted, the bearing and deformation of the formwork support system can not meet the requirements, and the overall safety can not be ensured; in the concrete pouring process, the traditional construction method cannot effectively control the dissipation of the hydration heat of the concrete, and too fast pouring construction can lead the templates to be stressed unevenly and deformed, so that the side templates are in an unsafe state; compared with the traditional construction method, the control method of the condensate pipe and the sectional and layered pouring is added, so that the concrete temperature change is effectively ensured to meet the standard requirement, and the structure is ensured not to crack.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a construction method of a radiation-proof concrete structure for a medical house, which solves the problems of a large-volume concrete crack resistance technology, a reinforced bar engineering, a structural formwork engineering, a concrete pouring engineering and a construction process control method for concrete molding protection, ensures the quality of the medical building structure to be superior, and meets the requirement of using functions.
In order to solve the technical problems, the invention is realized as follows:
the construction method of the radiation-proof concrete structure of the medical house is characterized by comprising the following two parts:
a first part: and (3) foundation slab structure construction: the method comprises the steps of earth excavation, concrete cushion layer, waterproof and protective layer, baseboard reinforcement binding, embedded part, baseboard concrete pouring and baseboard concrete maintenance;
a second part: construction of a wall and roof structure: the method comprises the steps of binding wall steel bars, installing embedded parts in the wall, checking and accepting, installing wall templates, installing opposite-pull screws for reinforcing templates, erecting a support frame, installing a top plate template, binding plate steel bars, installing the embedded parts, checking and accepting, casting the wall, and maintaining the top plate concrete.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the bottom plate reinforcing steel bar ligature and built-in fitting in the first part specifically do:
firstly, measuring construction;
(1) Performing plane control by using a total station and a theodolite according to a coordinate control point and an elevation reference point provided by a construction unit, and performing elevation guiding measurement by using the level meter;
(2) Setting a deep coordinate point in a construction area according to requirements according to coordinate control points provided by a construction unit, and building a site control network by using the deep coordinate point; a certain point in the plane control network is used as a measuring point (meeting the requirements of sight and convenience) for rechecking the site control network;
(3) The elevation is based on a level point provided by a construction unit, the value of the elevation is based on the latest provided value of the construction unit, and construction Gao Chengying is adjusted in time according to the latest data;
(4) The measuring instrument is selected from:
the measuring instrument used in the engineering mainly comprises a total station, a theodolite, a level gauge, a steel ruler and a tower ruler;
(5) Control of measurement accuracy and error range;
1) Angle measurement: adopting a back measurement method, wherein the error in the angle measurement is within 2' and the total error is within 2 mm;
2) Distance measurement: measuring with the identified steel tape;
3) The deviation between the axes of each layer is within 5mm, the vertical deviation of the layer height is within 5mm, and the vertical deviation of the total height is within 30 mm;
(II) excavating residual soil;
at the position 300mm away from the designed elevation of the substrate, a horizontal line is cut out, small wood piles are nailed, and then a temporary soil layer is dug away manually; after the substrate is repaired and leveled, quality inspection and acceptance are carried out; after digging to the designed elevation, timely notifying construction, investigation, design and supervision units of checking the grooves, forming groove checking records, and immediately constructing cushion layer concrete after the groove checking records are qualified;
thirdly, pile head treatment;
(1) Ejecting a cutting control line at a position 20mm above the pile top design elevation;
(2) Cutting a circle along the control line by using a portable cutting machine, wherein the cutting depth is preferably not contacted with the main rib;
(3) Stripping out the main reinforcement by using an impact drill and a pneumatic pick, then breaking pile core concrete by using the pneumatic pick or a hammer and a kettle, and finally chiseling and flattening the pile top by using the kettle;
(4) The pile head main rib of the filling pile should be corrected and the anchoring length is ensured. The main rib is strictly forbidden to be cut off, and no straight bending exists;
(5) Pile head waterproof reference method: the pile top and the periphery are coated with cement-based waterproof paint, the surface of a cushion layer around the pile is coated with a width not less than 200mm, the closing-in position of coiled materials around the pile is sealed by waterproof ointment, and a water-swelling water-stopping ring is arranged at the root of a pile main rib;
fourthly, constructing a foundation template;
brick die: autoclaved aerated concrete blocks 600mm by 200mm by 240mm, concrete solid brick blocks 240mm by 115mm by 53mm, and the two brickwork are mainly used for building super-high foundation bearing platforms, elevator shafts and retaining brick dies of water collecting wells; when the masonry height is 1200 < H and less than or equal to 2000, autoclaved aerated concrete blocks 600mm by 200mm by 240mm or solid bricks are adopted for masonry, and the thickness is 200 thick; when H is more than 2000, the parts below two meters are built by adopting concrete solid brick blocks 240mm 115mm 53mm, and the parts are built by adopting autoclaved aerated concrete blocks or solid bricks; when the wall length is greater than 2.5m, a 500mm brick column is additionally arranged, and when the wall height is greater than 4m, a 200mm concrete ring beam is additionally arranged;
Prefabricated fetal membrane of finished concrete: the specification is 3000mm multiplied by 600mm multiplied by 90mm, and the length can be customized according to the requirement; the method is mainly used for a conventional rectangular bearing platform soil-retaining side template or a ground beam side template, wherein the soil-retaining height H is less than or equal to 1500, and H is less than or equal to 1200, and a single-layer soil-retaining precast concrete bed-jig or solid brick is adopted for masonry;
(1) After the cushion layer construction is completed, popping up a bearing platform foundation positioning line;
(2) Installing a finished brick moulding bed along the marked line, and fixing the finished brick moulding bed through a reinforcing steel bar head;
(3) Reinforcing the seam of the fetal membrane through the templates and the battens to ensure the flatness and stability of the seam;
(4) Backfilling earthwork before removing the reinforced inner support, and binding iron wires on the steel bars to reinforce the periphery;
(5) The inner support can be dismantled and reinforced after the waterproof cushion layer is poured;
(6) And (3) reserving an outer wall construction joint: continuously pouring the wall body and the top plate at one time, and reserving a construction joint between the bottom plate and the outer wall at the position of 300mm in elevation;
binding reinforcing steel bars;
1) The process flow comprises the following steps:
binding beam steel bars, placing beam bottom cushion blocks, binding bottom plate steel bars, placing plate bottom cushion blocks, paying out wall column position lines on the steel bars, installing wall column dowel bars, reserving and embedding water and electricity heating, self-checking, mutual checking, handover checking, reporting, supervision and inspection acceptance;
2) Binding the reinforcing mesh. The intersection points of two rows of the reinforcing steel bars around the unidirectional stressed reinforcing steel bars are firmly tied at each point, the intersection points of the middle part can be tied in an intersecting and staggered manner, and the reinforcing steel bar net of the bidirectional main reinforcing steel bar is firmly tied at all reinforcing steel bar intersection points;
3) The bottom plate steel bars adopt double-layer steel bar meshes, and a steel bar split heads, steel bar supports or angle steel supports are arranged between the upper layer steel bar meshes and the lower layer steel bar meshes so as to ensure that the positions of the steel bars are correct; the hooks of the lower layer of steel bars face upwards, and the hooks of the upper layer of steel bars face downwards;
4) The hidden column is connected with the inserted bar for the foundation, and the bending section at the tail end of the inserted bar is firmly fixed with the steel bar of the bottom plate;
5) The reinforcing steel bars of the basement bottom plate extend to the outer edge of the bottom plate;
6) The plate construction is noted in the figures;
7) The long-direction reinforcing steel bars of the bottom plate of the plate are arranged above the short-direction reinforcing steel bars; the long negative ribs of the plate at the support seat are arranged below the short negative ribs, and the length of the plate bottom ribs extending into the beam support seat is more than or equal to 10d and exceeds the center line of the beam;
8) When the bottom of the plate is level with the bottom of the beam, the lower rib of the plate is bent near the beam edge according to the gradient of 1:6 and then stretches into the beam and is arranged above the longitudinal rib at the lower part of the beam;
9) The holes on the plate are reserved, the holes with the hole size of more than 300mm are only shown in a general structural plan, all holes are reserved according to the cooperation of each professional drawing in construction, when the hole size is less than or equal to 300mm, the reinforcing steel bars are not additionally added to the hole edges, and the reinforcing steel bars in the plate are bypassed by the hole edges and cannot be cut off; when the size of the hole is more than 300mm, except for the person noted in the figure;
10 The slab reinforcement is not cut off at the equipment pipe well where the concrete slab is required to be plugged, and after the equipment pipe is installed, the compensation shrinkage concrete casting with the strength grade not lower than that of the slab concrete on the same floor is adopted;
11 When the pipeline is embedded in the plate, the pipeline is placed between the plate bottom and the plate top steel bars, and the outer diameter of the pipeline is not more than 1/3 of the plate thickness; when the pipelines are arranged in parallel, the horizontal clear distance between the pipelines is not less than 3d (d is the pipe diameter); when the pipelines are crossed, the thickness of the concrete protective layer of the pipeline at the crossing part should not be less than 25mm;
12 Exposed cast-in-situ reinforced concrete parapet, hanging plate, breast board, and Seriola, when the horizontal straight line length exceeds 12m, the induced seam should be arranged, the interval between the induced seams is not more than 12m, and the seam width is 20mm;
13 Double-layer bidirectional additional reinforcing steel bar meshes are additionally arranged at external corners of walls or beams of the roof abnormal plates of each floor, and when the cross floor is double-layer bidirectional through length reinforcing steel bars, if the spacing between the reinforcing steel bars at the plate corners does not meet the requirements, C8 short bars can be additionally added to meet the spacing requirements; the plate surface of the external corner of the roof cornice cantilever plate is additionally provided with a radial rib;
14 A construction diagram of related structures of the unequal-height plate reinforcement structure;
15 Except for the noted person, the length of the negative rib is calculated from the middle support in the middle support, and the edge support is calculated from the outer side of the beam;
16 Foundation mat reinforcement bracket arrangement principle):
the thickness of the bottom plate is 700mm (C20@150 double-layer bi-directional) except the indication; the thickness of the basement bottom plate with the height of only one layer is 500mm (C18@150 double-layer bidirectional) except the thickness;
(a) The steel bar support columns are arranged in a groined manner, a C20 steel bar pull rod is horizontally added to the middle of each column at the position of a local pit (such as an elevator foundation pit, a water collecting well and the like), the bottom plate beams with the thicknesses of 700mm and 500mm are all C22 steel bars, and the columns are respectively C20 steel bars and C16 steel bars;
(b) As shown in the following figure, the inclined strut C16 steel bars are not oriented in the same direction and are arranged at certain intervals left and right;
17 Basic raft steel bar bracket arrangement principle):
(a) The steel bar support columns are arranged in a groined manner, and a C20 steel bar pull rod is horizontally added to the middle of the columns at the position of a local pit (the position of an elevator foundation pit, a water collecting well and the like);
(b) As shown in the following figures, the diagonal braces are not oriented in the same direction and are arranged at left and right intervals;
(c) The figure is applicable to raft h=2200 mm (20@150) rebar scaffold arrangement;
18 A large-area foundation pile cap reinforcement bracket arrangement principle;
(a) The steel bar support upright posts are arranged in a groined manner;
(b) As shown in the following figures, the diagonal braces are not oriented in the same direction and are arranged at left and right intervals;
(c) The drawing is suitable for the arrangement of the reinforcing steel bar bracket with a larger area of bearing platform h=2100 mm (25@100);
(d) And when the height of the bearing platform is greater than 2m, a C12@200mm reinforcing steel bar net is arranged in the middle of the height of the bearing platform.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the bottom plate concrete placement in the first part specifically is:
firstly, construction requirements;
1) Basement bottom plate adopts inclined plane layering to pour, follows "inclined plane layering, and a slope (pumping concrete is 1: 6-1: 10 The thin layer covering and progressive principle, wherein the thickness of each layer is 500-600 mm, the layers are pushed from one side of the raft foundation to the other side, and then thin layers are poured and smashed in sequence and are topped once; gradually moving upwards from the lower end of the pouring layer during construction so as to ensure the quality of concrete;
2) All pump pipes are supported in place, and each row of conveying pipes are fixed in point and are in charge of each other during pouring;
3) Directly distributing materials on the surface of the bottom plate epithelial steel bar by using a pump pipe or a hose connected in front of the pump pipe, and on the premise of ensuring that the concrete does not generate cold joints, spreading the concrete in a fan shape by using the hose to move left and right, so that the spreading area of the concrete in the mold is increased as much as possible to increase heat dissipation and heat exchange;
4) Covering the poured concrete for a period of time not exceeding the initial setting time of the concrete so as to avoid cold joints;
5) According to the range of concrete flowing speed of the large-volume foundation slab, the construction of pumping concrete in the elevator shaft and the water collecting pit is needed to be carried out in advance, and the concrete is compacted by vibrating; pouring the concrete of the elevator shaft and the water collecting pit to be level with the large bottom plate, and tightly connecting the concrete part of the elevator shaft and the water collecting pit with the concrete part of the foundation bottom plate;
6) The concrete in the elevator shaft and the water collecting pit adopts an intermittent pouring method, the templates are made into a whole and erected in advance, the concrete is poured to be flat with the templates, when the mobility of the pit bottom concrete is not large and the pit wall concrete pressure can be born, the pit wall concrete is poured again, and the quality of the contact position of the bottom and the wall is ensured; the intermittent time is about 2 hours;
7) The pit bottom pouring sequence is pushed from one end to the other end in the length direction, or from two ends to the middle. Forming a ring loop on the pit wall for layered pouring; when the concrete on the side wall of the water pit is poured, a symmetrical pouring method is adopted to ensure that the stress of the side wall template is uniform;
8) After the concrete is poured and is coated for the first time, covering and curing are started, and a curing method of heat preservation and moisture preservation is adopted;
9) The covering method comprises the following steps: the bottom plate adopts a method of 'single-film single-layer geotextile', namely a layer of heat-preservation gunny bag is covered on a layer of plastic film; the side wall adopts a method of 'single-film double-layer geotextile', namely, a layer of plastic film is covered with two layers of heat-insulating geotextile; the heat-insulating geotextile is covered outside the side mould, so that the moisture and hydration heat on the surface of the concrete are not lost, the internal and external temperature gradients of the concrete can be reduced, the internal and external temperature differences of the mass concrete are ensured, and the strength growth and the crack control of the concrete are facilitated; the plastic cloth is covered and maintained without watering during heat preservation, so that the surface temperature is prevented from falling too fast, the covering tightness of the plastic cloth is ensured, the lap joint is not less than 200mm, bricks and square timber are pressed, and the side wall is fixed by element nails. The maintenance starting time is when the surface strength can be on the person; the plastic cloth cannot be uncovered at will to perform other operations on the concrete surface during maintenance;
10 During curing and temperature measurement, the highest temperature, the surface temperature and the atmospheric temperature of the concrete at each temperature control point are provided in time, so that the on-site heat preservation and curing are guided, the heat dissipation of the heat preservation layer is reduced at the midday and the afternoon to shorten the heat preservation and curing time, and the heat preservation and curing time is covered again at night;
11 Heat preservation time: according to the temperature measurement record, when the central temperature of the concrete starts to drop and approaches to the surface temperature, and the temperature difference between the central temperature of the concrete and the atmospheric temperature is less than 25 ℃, the heat preservation is started to stop; removing the plastic film and the heat-insulating gunny bag layer by layer, and keeping a certain time interval according to the measured temperature after each layer is removed so as to avoid generating larger temperature gradient;
12 According to the actual measurement data, firstly removing the upper heat preservation layer, then completely removing the heat preservation layer, and carrying out watering maintenance for at least 14 days;
13 The engineering mass concrete structure is of a rectangular structure, temperature measuring points are arranged on the most unfavorable section of the whole basic temperature, rectangular diagonal positions are arranged on the long sides of the rectangle, 4 points are symmetrically arranged on the half sides of each most unfavorable axis, one temperature measuring point is arranged on the center of a plane for the mass structure with smaller size, and three temperature measuring points are arranged along the thickness direction of the structure.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: binding wall steel bars in the second part specifically comprises:
1) The process flow comprises the following steps:
a, treating a root construction joint, overlapping and welding vertical steel bars, checking a welded joint, binding column stirrups, binding non-waterproof wall steel bars, placing cement stay bars, reserving and embedding water and electricity heating, self-checking, mutually checking, cross-checking, reporting, managing and checking;
b, root construction joint treatment, vertical steel bar overlap joint and welding, inspection of welded joints, binding of column stirrups, binding of waterproof wall steel bars, water heating reserved pre-embedding, installation of protective layer cushion blocks, self-checking, mutual checking, handover checking, supervision and inspection acceptance;
2) The hidden column stirrups are perpendicular to the stressed bars, the overlapping positions of the hooks are staggered and bound along the direction of the stressed bars, the crossing points of the corners of the stirrups and the longitudinal steel bars are firmly bound, the binding buckles are splayed when the stirrups are bound, the stirrups are flat and straight, the opposite angles of the openings are staggered and spirally bound, the specification interval is according to the drawing, and the tail parts of the binding wires face to the column center of the wall;
3) When the section of the wall column is changed, the bending part of the reinforcing steel bar must be within the height of the beam column wall node;
4) The beam connecting steel bars are arranged on the inner sides of the longitudinal steel bars of the wall columns;
5) Binding a reinforcing steel bar net of the wall with a foundation, wherein hooks of the reinforcing steel bars face the inner side of the wall column;
6) The shear wall body is manufactured by structures such as horizontal steel bars, vertical steel bars, edge members, connecting beams, hole reinforcements and the like;
7) The shear wall body is double-layer bidirectional reinforcement, the reinforcement is vertically distributed on the inner side, and the reinforcement is horizontally distributed on the outer side;
8) The lacing wires are arranged in plum blossom mode;
9) The horizontal distribution steel bars of the wall limbs in the height range of the shear wall connecting beam are used as waist bars of the connecting beam in the connection Liang Nala;
10 Manufacturing a shear wall constraint edge component structure;
11 Hole on wall must be reserved, and back chisel is not needed; for the discontinuous small hole, when the length of each side of the discontinuous small hole is less than 800mm, the discontinuous small hole is operated according to the sign and reinforced;
12 The allowable deviation of the templates and the walls of the shear wall must be strictly executed according to the relevant regulations of construction acceptance regulations, concrete must be poured and tamped in layers, the pouring heights of the first layer and each later layer must not be more than 500mm and 1000mm respectively, and the interface surfaces must be cleaned, so that good concrete combination is ensured;
13 The specification, the size, the spacing, the row spacing, the lap joint length, the anchoring length, the thickness of the protective layer and the like of the wall steel bars meet the design and specification requirements;
14 The binding of the reinforcing steel bars is firm, all the crossing points should be bound, and the binding buckle should face to the inner side; the positions of the binding overlap joints of the reinforcing steel bars are staggered, the staggered distance meets the requirement, and three binding buckles and three horizontal ribs pass through within the binding overlap range of the vertical ribs of the wall body;
15 The wall body drag hook is bound on the intersection point of the horizontal steel bars and the vertical steel bars, the superposition position of the hooks is bound in a staggered mode along the direction of the stressed steel bars, and the bound drag hook is clamped by a tool type clamp and then bent, so that the arrangement distance of the steel bars is unchanged.
16 A top mold rod for fixing the gate, a steel bar for fixing the box and a grounding wire are tightly forbidden to be welded on the stressed steel bar;
17 Wall measure reinforcing steel bar): in order to ensure that double-layer steel bars of the wall are horizontal and vertical, the distance is uniform and correct, and vertical ladder bars are used for limiting; in order to ensure the thickness of the wall, a short steel bar internal support is added at the opposite-pull screw rod, the two ends of the short steel bar are smooth, and antirust paint is brushed; after the wall rib is bound, correcting the position of a main rib of a door and window opening node to ensure the thickness of the protective layer; the number of the binding threads of the wall body steel bar lap joint is not less than 3, and the binding threads are inwards.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the installation wall body template in the second part specifically is:
1) Positioning and lofting the wall profile before installing the wall template, and alternately installing the template and the batten at one time until the whole wall is installed; before the template is installed, the positions of the opposite-pulling screws are calculated, holes are formed according to the specified intervals, and for the inner wall, the template can be installed first and then the screws are placed for reinforcement; for the outer wall, a counter-pulling water stop screw rod is arranged before the formwork is installed and erected, and then the whole reinforcement is carried out;
2) When the loose-splice shaping template is adopted for supporting the template, the template should be carried out from bottom to top, and the upper layer of the template can be installed after the lower layer of the template is completely fastened; when the lower layer cannot be independently provided with the supporting piece, temporary fixing measures should be taken;
3) When the prefabricated large wall templates are adopted for formwork erection, 2 templates are strictly forbidden to be lifted at the same time, and are positioned, corrected and connected at the same time, and the fixed templates can be unhooked;
4) Before installing the inner wall mould of the elevator shaft, a layer of scaffold board must be firmly fully paved at the position 200mm below the board bottom;
5) Before the split bolts are installed on the template, the plate surface is inclined backwards by a certain angle;
6) When the length of the steel ridge needs to be lengthened, the same number of steel ridges with the same specification or not less than the original specification are added at the joint, and the lap joint length of the steel ridge is not less than 15% -20% of the width or the height of the wall template;
7) The U-shaped cards are required to be installed in a positive and negative alternate mode during splicing, and the distance is not more than 300mm; the U-shaped clamp at the butt joint seam of the 2 templates is fully assembled;
8) The split bolts are vertical to the wall templates, the tightness is consistent, and the wall thickness is correct;
9) The internal and external supports of the wall form board must be firm and reliable, and the integral stability of the form board should be ensured; when the outside of the wall template cannot be provided with a support, the inside of the wall template is provided with a support capable of bearing tension and compression; when the wall templates are integrated with the support, measures should be taken to prevent adjacent templates from deforming when concrete is poured.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the erection support frame in the second part specifically is:
(1) The construction process flow;
paying off and checking, setting up a full framing, paving a main steel pipe keel, paving a wood keel and a wood veneer surface layer, performing self-checking and checking;
(2) Constructing a vertical rod and a horizontal rod;
1) Lap joint requirements: the upright posts at all parts of the project are connected by connecting sleeves, and overlap joint is forbidden;
2) The upright rod connecting sleeve can be a cast steel sleeve or a seamless steel tube sleeve; the length of the vertical rod connecting sleeve in the form of cast steel sleeve is not smaller than 90mm, and the insertable length is not smaller than 75mm; the length of the vertical rod connecting sleeve in the form of a seamless steel pipe sleeve is not smaller than 160mm, and the insertable length is not smaller than 110mm; the gap between the inner diameter of the sleeve and the outer diameter of the upright steel pipe is not more than 2mm;
3) The vertical rod and the vertical rod connecting sleeve are provided with anti-extraction pin holes for fixing the vertical rod connecting piece, the aperture of the pin holes is not more than 14mm, and the allowable size deviation is +/-0.lmm; the diameter of the upright connector is preferably 12mm, and the allowable dimensional deviation is +/-0.lmm;
4) Setting a sweeping rod at the position of the bottom of the vertical rod which is not higher than 500mm away from the ground according to a procedure of longitudinal and transverse directions along the longitudinal and transverse directions;
5) The horizontal rods in the longitudinal and transverse directions of each step are connected and pulled through the disc buckle nodes;
6) Before the vertical rod and the horizontal rod are erected, measuring and paying-off of beam slab rod pieces are carried out according to the erection requirement, the vertical rod point position is checked after paying-off is finished, and rod piece erection can be carried out according with the requirement;
(3) An adjustable base and a jacking;
1) The screw rods of the adjustable base and the adjustable bracket are preferably trapezoidal teeth, the A-shaped upright rod is preferably provided with a 48 screw rod and an adjusting handle, and the outer diameter of the screw rod is not less than 46mm; the B-type upright rod is preferably provided with a 38 screw rod and an adjusting handle, and the outer diameter of the screw rod is not smaller than 36mm;
2) The bottom plate of the adjustable base and the adjustable bracket supporting plate are preferably made of Q235 steel plates, the thickness of the adjustable base and the adjustable bracket supporting plate is not smaller than 5mm, the allowable dimensional deviation is 2mm, and the length and the width of the steel plates of the bearing surface are not smaller than 150mm; the steel plate of the bearing surface and the screw rod are subjected to ring welding, and stiffening sheets or stiffening arches are arranged; the adjustable bracket supporting plate is provided with an opening baffle, and the height of the baffle is not less than 40mm;
3) The screw rod of the adjustable base and the adjustable bracket is not smaller than 5 buckles, the thickness of the nut is not smaller than 30mm, the cantilever length of the adjustable bracket of the template bracket extending out of the top level rod or the double-groove steel joist is strictly forbidden to be more than 650mm, the exposed length of the screw rod is strictly forbidden to be more than 300mm, and the length of the adjustable bracket inserted into the vertical rod or the double-groove steel joist is not smaller than 150mm;
4) The exposed length of the adjusting screw rod of the adjustable base of the plate bracket is not more than 300mm, and the height of the bottom horizontal rod serving as the floor sweeping rod from the ground is not more than 550mm;
(4) Diagonal rod and scissors stay arrangement;
1) When the template support in the high formwork supporting area is erected, the vertical diagonal rods are required to be arranged according to the standard requirement, the step distance of the horizontal rods is not more than 1.5m, and the steel pipe fastener scissor supports are required to be arranged at intervals of 4-6 standard step distances along the height; when the periphery is provided with a structure, a reliable drawknot is formed with the periphery structure;
2) When the template support is set up into an independent tower-shaped support without lateral drawknots, each step of distance on each side face of the support body is provided with a vertical diagonal rod; when the torsion prevention requirement exists, a horizontal layer diagonal rod or a steel pipe horizontal scissor brace is additionally arranged on the top layer at intervals of 3-4 steps;
3) The steel pipe scissor support is fixed on a vertical rod or a horizontal rod which is intersected with the steel pipe scissor support by adopting a rotary fastener, and the distance from the center of the rotary fastener to a main node is not more than 150mm; the slenderness ratio of the scissors is not more than 200;
4) When the knife support is connected, the knife support is in lap joint, the lap joint length is not less than 1000mm, not less than 2 rotary fasteners are arranged, and the fasteners at the two ends are fixed at the position not less than 100mm away from the rod end;
5) The knife rest is synchronously erected along with the vertical rod and the horizontal rod in the longitudinal and transverse directions, and cannot be installed in a lagging way;
6) The horizontal scissor support needs to simultaneously tie the column frame body and the beam area frame body;
7) The project frame body adopts standard type support frame bodies, and the design value of the vertical rod axial force is within 40 KN; the specific arrangement requirements of the vertical diagonal rods are as follows:
the vertical shaft axial force design value and the scaffold setting height are the maximum value in the unified independent frame;
each span represents that the vertical diagonal rod is erected along the longitudinal direction and the transverse direction; the first span is the vertical diagonal rods are erected at intervals of 1 span along the longitudinal direction; interval 2 spans, 3 spans and so on;
(5) The spacing does not conform to the modulus adjustment;
1) Setting an adjusting span at the position of the plate when the modulus is not matched;
2) The adjusting span is arranged at the position with smaller bearing load under the plate, and is integrally formed by pulling the steel pipe with the common fastener at each step;
3) The horizontal rod extends to two ends and is at least buckled with the vertical rods of 2 shaping brackets;
4) Gaps with different distances exist in the erecting process of the Liang Banjia body, steel pipes are needed to be connected in a drawknot mode every span, and the connecting fasteners are connected to the vertical rods in a drawknot mode.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the roof template in the second part is installed, specifically:
1) The template can be sealed after the steel bar is concealed and accepted;
2) Template mounting sequence: a vertical structural die, a beam die and a platform die; after each single template is finished, the single template can be transferred to the next procedure after self-checking and technical rechecking; checking the upper port elevation when checking the vertical structure mould;
3) Carefully check the quality of the entry form, the wood form requires the use of a perfect splint. The various templates are required to be solid, smooth and intact; checking the size of the fixed processing template;
4) Ejecting all the beams, columns and wallboard edges according to the turnover diagram; the vertical template must be strictly processed according to elastic lines; the lower parts of the wallboards and the columns are limited by welding the reinforcing bars with the wall bars and the column bars;
5) Checking the positions, the sizes, the specifications, the number and the fixing conditions of the embedded parts and the reserved holes before installing the template; the method is coordinated with an installation unit, and the installation of the pipeline in the wall is guaranteed before the template is sealed;
6) Before the column and the wallboard mould are sealed, garbage and sundries in the mould are cleaned, and the floating ash is cleaned by compressed air;
8) The elastic wire vertical bent is required to be horizontal and vertical; the perpendicularity and the interval of the upright posts, the arrangement of the scissors supports and the arrangement of the joints when the upright posts are lengthened are in accordance with the scheme requirements;
9) The net span of the short side of the floor is more than or equal to 4m, and the arch starting value of the center of the floor is 2/1000 net span; the cantilever plate has a cantilever length of more than or equal to 1.5m, and the cantilever section end arching value is 4/1000 of the cantilever length. The span of the beam is more than or equal to 4m, and the span arch value of the beam is 1/1000-3/1000 net span; the beam span is more than or equal to 9m, and the arch starting value in the beam span is 1/500 net span;
10 The beam and column node templates have clear relationship and firm fixation; the joint part is inlaid by a 50mm thick wood die, and the thin plate is forbidden;
11 Flatness control and slurry leakage prevention operation points:
the side dies of the beam and the wallboard are arranged in staggered joint, the templates are tightly spliced, and a box sealing paper tape is stuck at the embedded joint;
before installing the column and the wallboard bottom templates, cleaning the root parts of the column and the wallboard bottom templates, leveling the vertical templates by using mortar to ensure that the elevation of the vertical templates is consistent and preventing slurry leakage from the root parts;
the template at the construction joint part of the stair is provided with a cleaning opening, so that quality common problems such as slag inclusion and the like are avoided;
12 The steel pipe fastener transverse and vertical enclosing purlins and the opposite-pulling screw rods are strictly arranged according to the requirements, the double-spliced transverse enclosing purlins are arranged in a unified length mode, joints are staggered, and hook head bolts are arranged according to the requirements of a turnover diagram so as to effectively control the section size of a component and strengthen the overall rigidity of a beam and a wallboard;
13 The long twine is pulled and fixed firmly with the bent frame when the side die is fixed;
14 The template is installed to be positioned correctly, supported firmly and the plate surface is flat; the special person takes charge of checking and rechecking.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the binding plate reinforcing steel bars in the second part are specifically as follows:
1) The process flow comprises the following steps: installing beam steel bars, sinking beams, correcting and arranging bottom surface and side surface steel bar protection layer cushion blocks, installing plate steel bars, installing plate steel bar protection layer cushion blocks, pre-burying, installing plate surface layer steel bars (upper layer steel bars if double-layer steel bars are adopted), supporting, installing split heads, self-checking, mutually checking, special checking, reporting, supervision and acceptance.
2) The protective layers of the steel bars at the bottom and the side of the beam adopt mortar/concrete cushion blocks, the steel bars of the beam adopt overhead binding, the beam is submerged by other equipment such as a hoist, and the like,
3) Bending the beam main reinforcing steel bars when the length of the horizontal section of the beam main reinforcing steel bars extending into the wall column is smaller than the anchoring length so that the beam main reinforcing steel bars meet the anchoring length; when the length of the horizontal section of the secondary beam extending into the main beam is less than 0.4La, the joint of the primary beam and the secondary beam should be respectively bent downwards and upwards; if the support meets the anchoring length of the main steel bar of the beam, the steel bar at the bottom of the beam extends at least 5d beyond the axis; when two rows of beam main steel bars are arranged, a cushion block (the short steel bars with the thickness phi of 25) with the thickness not less than 25mm is arranged between the two rows of steel bars; the lap joint binding joints should be provided with three-point binding, and any joints must be staggered; binding each point of the crossing point of the stirrup and the main bar, and folding the end part of the binding wire into the framework;
4) The intersection points of two rows of steel bars at the periphery of the unidirectional plate are all bound, the intersection points of the middle part can be indirectly bound, and the intersection points of the bidirectional stressed bars are all bound;
5) The plate hogging moment bar is positioned by adopting an I-shaped split heads, and the split heads are arranged at the end parts of the hogging moment bars;
6) The steel bar connection mode comprises binding connection, mechanical connection and welding, and the engineering frame column longitudinal bars are preferably mechanically connected; the beam longitudinal reinforcement joint is suitable for avoiding a beam end stirrup encryption area, and mechanical connection cannot be adopted when avoiding; other parts can be bound; the diameter d of the steel bar is more than or equal to 22, and the longitudinal bars of the conversion beam are mechanically connected;
7) Arranging a reinforcing steel bar support frame;
the thickness B=1600 mm of the top plate of the machine room, and the plate reinforcement C25@150mm is double-layer bidirectional; and tie bars which are arranged in a bidirectional quincuncial manner and C8@600 are arranged between the two steel bar meshes in the wall body and the top plate of all the machine rooms.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the concrete of the cast wall and the roof in the second part is specifically:
firstly, constructing mass concrete;
(1) Pouring concrete;
1) The integral and impervious performance requirements of the large-volume concrete foundation slab are high, concrete is poured continuously, and no construction joint is left;
2) Adopting a layered pouring method, wherein the layered pouring can be performed by adopting inclined plane layering and block layering methods;
under the condition of ensuring continuous casting of each layer, the intermittent time between the layers is shortened as much as possible, and after the casting of the lower layer concrete is finished, the pipe is firstly disassembled and returned to the initial casting position, and then the upper layer concrete is cast, so that the continuity of the whole concrete casting process is ensured. The casting thickness of each layer of the large-area concrete is controlled to be about 500 mm;
3) Marking lines of the vertical indicating rod before casting to mark casting thickness of each layer; during pouring, a pump pipe distributing machine is adopted, and each pump is responsible for one area; the total time of concrete transportation, pouring and intermittence does not exceed the initial setting time of the concrete; the construction sequence is reasonably arranged in construction, the concrete is controlled to uniformly rise in the pouring process, the layered pouring can fully radiate hydration heat of the lower layer concrete in the initial setting time, the heat storage capacity of the concrete can be reduced, the accumulation of the hydration heat is prevented, and therefore the temperature stress is reduced;
4) The free falling height is not more than 2m when the concrete is poured, and if the free falling height is more than 2m, a method of lengthening a hose and stringing barrels is adopted; during the pumping process, enough concrete should be in the hopper to avoid the blockage caused by air suction;
(2) Vibrating the concrete;
1) After the concrete is put into a mould, the concrete is flattened and vibrated in place by an inserted vibrating rod;
2) In the pouring process, concrete vibration is an important link, the concrete is strictly operated according to an operation rule, quick insertion and slow pulling are realized, the quick insertion is used for preventing bubbles in lower-layer concrete from being discharged after the compaction of upper-layer concrete, and the slow pulling is used for enabling the concrete to fill up a cavity caused by a rod; in the vibrating process, the vibrating rod slightly moves up and down to compact the concrete, the insertion points are uniform, the distance between the insertion points is controlled to be 50cm, and the distance from the template is 20cm; the single row form is adopted, and the concrete is not required to be mixed with the staggered type so as to avoid vibration leakage, the vibration point time is generally controlled between 20 and 30 seconds until the surface of the concrete is flooded, no air bubbles appear, and the concrete is not sunk;
3) The vibrator can not collide with the reinforcing steel bars, the templates and the embedded parts during vibration;
4) The intermittent time is accurately controlled in the pouring process, the upper layer concrete is poured before the lower layer concrete is initially set, and when the upper layer concrete is vibrated, a vibrating rod is inserted 5cm downwards, so that the upper layer concrete and the lower layer concrete are better combined;
Secondly, concrete construction measures are taken;
(1) Technical measures;
in order to ensure the construction quality of concrete engineering, the following measures are adopted:
1) In order to ensure that the concrete is not cracked, a water reducing agent is added into the concrete;
2) In autumn and winter, the average temperature of the Hangzhou is 17-25.3 ℃, and the concrete pouring should avoid weather; controlling the surface temperature of the concrete to be not more than 30 ℃;
3) And (3) treating the concrete surface of the construction joint: roughening the loose concrete part to expose the hard part, and cleaning with water;
4) In the concrete pouring construction, the protection of reserved and embedded parts is paid attention to;
5) Professional training is carried out on management staff before construction, technical communication is carried out step by step, and construction control key points of a linear accelerator machine room are familiar;
(2) Concrete temperature control and shrinkage crack pre-control measures;
1) Controlling the temperature of the concrete;
in order to effectively control the occurrence and development of harmful cracks, measures which are comprehensively considered in the aspects of controlling hydration temperature rise, delaying temperature reduction rate, reducing shrinkage of concrete, improving ultimate tensile strength of concrete, improving constraint conditions, designing structures and the like of the concrete are necessary;
2) Reducing the temperature of concrete entering a mould;
the retarder is properly used in the concrete stirring engineering to prolong the initial setting time of the concrete, the initial setting time is adjusted to 8-10 hours, and the hydration heat peak is delayed, so that the internal temperature of the concrete is reduced, and the molding temperature of the concrete is controlled;
3) Cooling measures in the concrete pouring process;
the length of the concrete conveying pipe is reduced as much as possible, the elbow is reduced, so that the loss in the concrete slump conveying pipe and the concrete molding temperature are reduced, the concrete is poured in a slope layering and step-type propelling mode, the thickness of each layer of concrete pouring is reduced under the condition that cold seams are not formed, and the thickness of each layer is not more than 300mm, so that hydration heat is sufficiently dissipated in the pouring process, and the later hydration heat is reduced;
(3) Other pre-control measures;
a. when the concrete is poured, the vibration is compact, so that the shrinkage is reduced, and the cracking strength of the concrete is improved. And the panel is smeared and pressed, and the secondary smeared and pressed can be carried out after the initial setting and before the final setting of the concrete so as to improve the tensile strength of the concrete and reduce the shrinkage;
b. the surface of the concrete is subjected to heat accumulation and moisture preservation maintenance, so that the moisture in the concrete can be effectively sealed and evaporated, the concrete can be maintained under a humid condition, the generation of shrinkage cracks is controlled, and a gunny bag is covered for heat preservation, so that the surface heat dissipation is reduced;
c. the moisture preservation maintenance can smoothly carry out cement hydration, improve the ultimate tensile strength of concrete, reduce temperature stress and shrinkage cracks on the surface of the concrete, and finally ensure that the temperature gradient of the internal and external concrete is within the allowable range of design and specification;
d. When gunny bags are hung on the outer side surface and the inner side surface of the wall die, the gunny bags are covered in a strip shape by using iron wires, a cover Yan Tieshi is fixed on the enclosing purlin, and the gunny bags are plugged in the wood baffle area grid; intelligent spraying, heat preservation and moisture preservation are carried out for at least 14 days during maintenance;
e. during the heat preservation period, especially when the top plate is in heat preservation, the linear accelerator chamber entrance door is closed, so that heat dissipation can be effectively prevented;
f. during the heat preservation period, the fire prevention safety work of the adjacent areas is required to be done, and the operation of smoke and nearby fire is strictly forbidden;
g. the removal time of the heat preservation layer refers to the analysis result of the temperature measurement data of the mass concrete engineering; the concrete method is that the insulation materials are removed in layers, and the construction personnel is forbidden to remove the form in advance without permission;
thirdly, constructing a large concrete in a machine room;
pouring concrete of a bottom plate, a wall body and a top plate in layers according to the height of each 300mm, pouring 1 day pump and 1 ground pump into 3 direct-adding machine rooms at the same time, and dividing the pouring range of each pumping mechanical equipment according to the arm length of the day pump and the concrete pouring experience of the bottom plate; and taking 3 pouring points for wall concrete, and pouring by the pumping mechanical equipment in a revolving way within a range. Taking a pouring point every 4 meters of roof concrete, and circularly pouring 3 pumping mechanical equipment from two sides to the middle in the respective range;
Casting a beam slab column in a common area: firstly pouring and constructing a C50 structural column and a shear wall of a main building area, and then pouring a shear wall column of an inner and outer wall connecting area, wherein the connecting parts with different marks are required to be synchronously poured on two sides; the basement outer wall is poured in layers, the layering thickness is not more than 50 cm, and the construction cold joint is prevented from occurring by continuous pouring in place;
pouring in a linear acceleration machine room: synchronous pouring of the inner wall and the outer wall, layered synchronous pouring of different labels, taking joint parts of the inner wall and the outer wall as boundaries, pouring from far to near, and pouring impervious parts of the outer wall preferentially, wherein slurry is continuously removed in the process, so that concrete is not accumulated; the overall layered casting height is controlled at 30 cm;
(IV) designing a mixing proportion;
(1) The concrete design requirement;
1. a concrete expansion agent;
1) The engineering basement structure is very long, and the shrinkage-compensating concrete doped with the expanding agent is used for casting and tamping;
2) The adopted expanding agent meets the technical requirements;
3) The material selection, mix proportion design, construction, maintenance, quality inspection and the like of the compensating shrinkage concrete should meet the regulations of related special regulations, specifications or construction methods; the prepared compensating shrinkage concrete is required to be controlled to be maintained in water for 14 days, the requirement of limiting expansion rate is shown in the table, and a compensating shrinkage concrete mixing ratio test is required to be made before construction, so that the design requirement is met; performing spot check on the limited expansion rate of the concrete in construction;
4) Test reference doping amount: post-pouring belt, reinforcing belt-40-60 kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the The rest positions are-30 kg/m to 50kg/m 3
5) The expanding agent is not suitable for being used in combination with the chloride-type additive, and the expanding agent should be cautious when being used in combination with the antifreezing agent;
6) The expanding agent does not contain aluminum powder, and the alkali content is less than or equal to 0.75 percent;
7) The admixture such as silica fume, zeolite powder, limestone powder, kaolin powder and the like is tested and demonstrated before the admixture such as foaming agent, accelerator, underwater non-discrete concrete admixture and the like is used together with the expanding agent;
2. adding anti-cracking fibers to the concrete;
1) The basement bottom plate, basement outer wall and top plate of the engineering require to be doped with polypropylene anti-cracking fiber 0.9kg/m 3 .
2) The geometrical characteristics and main physical and mechanical index requirements of polypropylene fibers:
shape: y-shape; diameter: 18-20 mu m; length of: 6 or 9mm of the diameter of the tube,
density of 0.91g/cm 3 The tensile strength is more than or equal to 400MPa;
the elastic modulus is more than or equal to 3500MPa, and the elongation at break is 15% -20%;
3) The fiber has chemical stability in the concrete mixture and hardened concrete, the strength is not reduced, the fiber is easy to disperse and uniform in the concrete mixture and cannot agglomerate; and has good bonding performance with hardened concrete;
4) When testing fiber concrete, the mixing proportion is determined according to common concrete without considering the influence of the fiber on the compressive strength of the concrete;
5) The fiber has alkali resistance, is not corroded by cement alkaline hydrate in concrete, and has chemical stability to concrete additives;
(2) Designing a concrete supply mixing proportion;
the mass concrete used in the project is produced and supplied by a commercial concrete mixing plant; the project department should carry out special mix proportion design with the concrete mixing station according to the characteristics of the mass concrete; because the structural sizes of the basement bottom plate and the wallboard of the linear accelerator machine room are large in difference, the proportion design is preferably carried out separately;
1) Ordinary silicate cement with low hydration heat is selected, and the cement strength is not lower than 42.5Mpa; the 3d hydration heat is not more than 250kJ/kg, and the 7d hydration heat is not more than 280kJ/kg; the tricalcium aluminate content should not be greater than 8%;
2) The fine aggregate is preferably middle sand, the fineness modulus is preferably more than 2.3, and the mud content is not more than 3%; the sand rate is preferably 38% -42%;
3) The non-alkali active coarse aggregate is selected, the particle size of the coarse aggregate is preferably 5.0-25 mm, the particle size of the coarse aggregate can be properly selected to be large on the premise of not influencing pumping construction, the coarse aggregate is continuously graded, and the mud content is not more than 1%;
4) A certain amount of fly ash or granulated blast furnace slag powder is preferably mixed into the concrete to replace part of cement, so that the hydration heat is reduced; the class F class I or class II fly ash is preferably adopted, the mixing amount is not more than 50% of the dosage of the cementing material, the slag powder is preferably S95 grade, the specific surface area is not more than 420 square meters per kg, and the mixing amount is not more than 15% of the dosage of the cementing material; the total mixing amount of the fly ash and the slag powder is not more than 50% of the dosage of the cementing material;
5) Proper amount of additive is added to the concrete. Such as retarder, for reducing early hydration heat of cement; the water reducing agent reduces the unit water consumption and the cement amount; and (3) an expanding agent fills in the gaps of cement, enhances the self-healing capacity of concrete, reduces cracks and the like. The expanding agent adopts calcium sulfoaluminate, the recommended blending amount is 10%, and the specific blending amount is determined by a test;
6) The mixing water dosage is not more than 170kg/m 3
7) The water-gel ratio of the mixture is not more than 0.45, the dosage of the cementing material is preferably 320-350 kg/m 3 The content of chloride ions is not more than 0.10% of the total amount of the cementing material, and the content of alkali is not more than 3.0kg/m 3
8) The specific mixing proportion is designed and determined according to comprehensive experimental consideration by combining the principle;
a. the mixture has good workability, fluidity, cohesiveness, water retention and other properties, and the slump is 160+/-20 mm;
b. the prepared mixture has retarding time and slump loss meeting construction requirements, and the slump loss of 1 hour is less than 30mm;
c. the concrete pumping performance is improved by mixing high-quality fly ash and slag powder, the hydration heat is reduced, and the release speed of the hydration heat is delayed;
d. selecting an FST-6 polycarboxylic acid high-performance water reducer, reducing the water-cement ratio, delaying the release speed of hydration heat and improving the crack resistance of the concrete;
e. The mixing ratio is a mass concrete mixing ratio, and 60d strength is adopted as a concrete strength index;
f. according to the early production and trial-and-development experience of a laboratory, the mixing ratio of C40 and C40P8 is finally determined;
(V) supply and transportation of concrete;
1) The sand and stones in the storage bin of the concrete mixing station should be covered by sunshade;
2) The temperature of the cement entering the machine is not higher than 60 ℃;
3) Ice water can be used for mixing, so that the temperature of the concrete outlet machine is reduced;
4) The weather forecast is closely concerned, and concrete pouring construction is avoided in rainy days, particularly in stormy weather;
5) Before pouring and opening, testers and quality staff are all in place, so that the slump and the expansion degree of concrete of each truck are ensured to meet the site construction requirements; the technical data carried by technicians at the commercial mixing station reaches a construction site along with concrete produced by a first vehicle, and the technical data and site constructors monitor the workability of the concrete together to provide site technical service; the tester visually detects the slump and the expansion degree of the concrete delivered from each car, and tests the slump and the expansion degree when necessary, so as to strictly forbid delivery of unqualified products;
6) The engineering adopts commercial concrete;
7) The material transportation in the rush hours of the early night and the rush hours of the next shift should be avoided;
8) The large-volume concrete transport vehicle should have certain sun-proof measures;
9) In the transportation process, the performance of the mixture is not adjusted by adding water into the mixture; when the additive is needed to be supplemented for adjustment, the stirring transport vehicle should stir rapidly, and the stirring time should not be less than 120s;
10 When slump loss or segregation is serious in the transportation process, pouring into a mould is not needed when the working performance of the concrete mixture cannot be recovered by taking measures;
11 The concrete amount of the engineering is large, the pouring time is long, and traffic is dredged in time;
pouring and vibrating concrete;
1) The engineering linear accelerator machine room is preferably constructed by adopting integral layered pouring; the layering thickness is 300mm and is not more than 1.25 times longer than the vibrating rod, and the interlayer intermittent time is not more than the initial setting time of the concrete; in the pouring process of each layer of concrete, a method of 'one gradient, thin layer pouring, timely vibrating and one-time top' is adopted, so that the continuous pouring of a thick bottom plate is ensured, the occurrence of construction cold joints is avoided, the radiating surface of the concrete is increased as much as possible, and the early-stage concrete hydration heat dissipation is facilitated;
2) The on-site scheduling management is reinforced when the concrete is poured, so that the poured concrete is covered by the upper layer concrete before initial setting and no cold joint is generated;
3) In the pouring process, the performance of the concrete is not required to be adjusted by adding water into the concrete; the concrete slump must be tested for each car, a tester is responsible for testing the concrete slump constructed on the day, constructors test the slump of each car, and is responsible for checking whether the slump of each car meets the technical requirements of commercial concrete tickets and making slump test records; the slump of the mixture is preferably controlled to be 120-160 mm, and the maximum slump cannot exceed 180mm; if the concrete cannot reach the construction conditions, immediately returning to the concrete mixing station;
4) The temperature of the concrete in the mould is controlled to be 5-30 ℃, and when the conditions permit, the concrete pouring is avoided in a high-temperature period;
5) The vertical falling height of the concrete is not more than 2.0m, and when the conditions are not met, a chute or a string cylinder can be adopted for auxiliary construction;
6) Firstly, scraping the surface of the concrete by using a long scraping ruler, rolling for a plurality of times by using an iron roller before initial setting, and then polishing and compacting by using a wood trowel to close a water collecting crack;
7) In the pouring process, the conditions of the steel bars and the embedded parts are observed frequently, when deformation and displacement are found, pouring is stopped immediately, and measures are taken immediately to finish the concrete well before the poured concrete is coagulated;
8) The concrete is vibrated by using a high-frequency vibrator, the distance between inserting points of the vibrator is 1.5 times the action radius of the vibrator, the concrete is required to be quickly inserted and slowly pulled out during the vibration, and in the vibration process, a vibrating rod is slightly pulled up and down so as to uniformly vibrate up and down, and the vibrating rod is required to be inserted into the lower layer by about 50mm so as to eliminate a joint between the two layers; the vibrating time of each point is preferably 20-30S, but the concrete surface is not obviously sinking any more, no bubble is generated on the surface, and even cement paste is spread on the concrete surface; the steel bar, the template and the embedded part are forbidden to be contacted during vibration; preventing leakage vibration and over vibration;
2) After the concrete is poured, carrying out secondary vibration before the concrete approaches to initial setting for 3-4 hours, and then scraping with a scraping ruler according to elevation lines and lightly wiping and pressing;
3) The surface cement paste of the mass concrete is thick, and bleeding phenomenon and floating paste are serious and should be carefully treated. The concrete surface treatment is performed with three pressing and three leveling; firstly compacting by using a clapping plate according to the elevation of the surface, and scraping by using a long scraping rule; secondly, rolling and leveling the steel plate by using an iron roller for several times before initial setting; finally, before final setting, polishing, compacting and leveling by using the wood crabs to close the water receiving cracks of the concrete; the rolling marks should be mutually connected when the iron roller rolls, and the times are respectively and vertically long and short;
seventh, concrete surface crack prevention control measures;
after the pumped concrete is vibrated, the surface cement paste is thicker, and surface cracks are easy to cause;
firstly, when the uppermost layer of concrete is vibrated, the vibration time is controlled, and the phenomenon that a thick floating slurry layer is generated on the surface layer is avoided; after pouring and tamping, a 2m long aluminum alloy scraping rule is needed to be used for scraping off the redundant floating slurry layer in time, melon seed slices are used for wiping and pressing, and the concrete surface is scraped and beaten to be flat according to a preset elevation control point; the pit-containing part is filled with concrete, when the concrete slurry is collected to be close to the initial setting, the concrete surface is subjected to secondary trowelling, and the wood trowelling is comprehensively and carefully smeared twice, so that the flatness of the concrete is ensured, the shrinkage dehydration fine seam on the initial surface is closed, and other people except concrete constructors cannot walk on the concrete surface which is not dry and hard at will during the concrete slurry collecting and setting construction;
(eight) placing a concrete test block;
each pouring, the concrete compression-resistant test block and the impervious test block are manufactured together with a commercial concrete factory representative according to the standard requirements, and standard maintenance and on-site maintenance under the same conditions are carried out;
1) Sampling the concrete with the same mixing proportion of not more than 100m3 for each mixing of 100 plates;
2) When the concrete mixed by each working class with the same mixing ratio is less than 100 plates, sampling is not less than once;
3) When one-time continuous casting exceeds 1000m < 3 >, sampling concrete with the same mixing ratio every 200m < 3 > at least once;
4) The concrete with the same mixing proportion is sampled at least once for each floor;
5) The waterproof concrete impervious test pieces are continuously poured in the same mixing ratio, wherein one impervious test piece is reserved every 500m < 3 >, and one impervious test piece is 6 impervious test pieces and is not less than 2 impervious test pieces;
6) At least one group of standard maintenance test pieces is reserved for each sampling;
7) The retention of the test blocks is ensured to be in charge of personnel special for project department, the weather condition and the temperature of each day must be recorded in detail by a data room under the same condition, and each group of test blocks are summarized and sent to a detection center in advance for test when the speed reaches 600 ℃/d.
The construction method of the radiation-proof concrete structure for the medical room is characterized by comprising the following steps of: the structural concrete curing construction specifically comprises the following steps:
1) After pouring is completed, adopting a heat preservation and moisture preservation measure of covering a film and covering geotextile; the inner wall adopts the measure of spraying maintenance with a mould, the outer wall is covered with a film and covered with geotextile for maintenance after the mould is removed, the top plate is covered with a film and geotextile for maintenance, and mortar is used for painting the back sill for water storage maintenance after the strength is reached;
2) The mass concrete should be maintained by heat preservation and moisture preservation; after the concrete is poured, covering or spraying maintenance work is needed to be carried out immediately before initial setting; maintaining the temperature for not less than 14 days; the temperature difference (without concrete shrinkage equivalent temperature) between the inner surface and the outer surface of the concrete casting body is not more than 25 ℃, the cooling rate of the concrete casting body is not more than 2.0 ℃/d, the alarm temperature is 1.5 ℃, the temperature difference between the surface of the concrete casting body and the atmosphere is not more than 20 ℃, and the alarm temperature is 18 ℃;
3) The bottom plate and the floor concrete are cured by adopting a method of covering the thin film with geotextile, adding water and retaining water for curing; the insulation coating is removed gradually in layers, and when the maximum temperature difference between the surface temperature of the concrete and the environment is less than 20 ℃, the concrete can be completely removed; spraying and curing with templates are adopted on two sides of the inner wall and the outer wall of the linear accelerator machine room, and an intelligent spraying system is used for curing for not less than 14 days;
4) The temperature difference change is effectively controlled by adopting a heat preservation and moisture preservation maintenance method;
After the concrete is finally set, a plastic film coating is adopted on the surface of the concrete, so that moisture on the surface of the concrete cannot be lost, and the upper cover geotextile is covered by heat insulation, the surface of the concrete is maintained by water storage, the wall is maintained by spraying with a mold, and the time for protecting the mass concrete is not less than 14d; ensuring that the difference between the center temperature and the surface temperature of the concrete is not more than 25 ℃;
5) A temperature control method of cooling by adopting a circulating condensate pipe is adopted;
circulating condensation water pipes are uniformly distributed in the walls and the plates of the machine room, and when the temperature difference between the inside and outside of the concrete exceeds a temperature control value, the temperature is controlled by timely passing through the condensation water, so that the temperature is prevented from rising too fast;
installing cooling water circulation cooling pipe networks between wall steel mesh sheets after binding of the machine room wall steel bars is completed and before installing the templates, and connecting the cooling water circulation cooling pipe networks by using DN40 galvanized steel pipes, wherein steel pipe risers are reliably fixed on wall steel mesh sheet additional ribs by using binding tapes; binding the reinforcing steel meshes at the middle layer of the floor slab, and horizontally installing a cooling water circulation pipe network in the floor slab by using a DN40 galvanized steel pipe; after the concrete curing period is finished, the cooling water circulation pipe network uses 1: and (5) performing grouting filling on the high-grade expansion cement mortar with the weight of 0.5. The water pipes are arranged at intervals of 1500 in the transverse and longitudinal directions and are arranged at the central position of the wallboard;
And (3) temperature control:
1) The engineering temperature measurement adopts a JDC-2 portable electronic temperature measuring instrument to measure the temperature, and consists of a host machine and temperature measuring wires, wherein the host machine is a portable instrument and is provided with a power switch, an illumination switch, a socket and a liquid crystal display screen, the measured temperature value can be digitally displayed, the temperature measuring wires are embedded and are made of plugs, wires and temperature sensors, and each temperature measuring wire can measure one point of temperature; the temperature measuring wire is pre-buried before concrete pouring, a power switch of the host computer is pressed down when temperature measurement is completed after pouring, a plug of the temperature measuring wire is inserted into a socket of the host computer, and a display screen of the host computer can display the temperature of a corresponding temperature measuring point;
2) The large-volume concrete pouring body is responsible for heat preservation and maintenance work by special personnel, and is subjected to test records, wherein the test items are temperature difference between the inner surface and the outer surface, cooling rate and environmental temperature; the temperature measurement time interval is 2h after 1-3 d, 4-7 d is 4h after concrete pouring, and 8h after the concrete pouring; the mold entering temperature is measured, and each shift should not be less than 2 times; the temperature measurement duration time is from the time when the initial setting of the concrete pouring is finished to the time when the maximum temperature difference between the surface temperature of the concrete and the environment is measured to be less than 20 ℃, and the temperature is maintained after the removable covering, and is not less than 14d;
3) Monitoring points in the large-volume concrete casting body are arranged at the middle positions of a 3-surface thick wall with the thickness of 3000mm and a 2-block thick plate with the thickness of 2500mm, and are 5 points in total and fixed in place by adopting steel bars;
4) When measuring the temperature, firstly, using a thermometer to test and record the ambient air temperature and the temperature of the concrete surface; then, testing the temperature by using a temperature measuring instrument according to the serial number sequence of the temperature measuring points, and reading data after the display number of the temperature measuring instrument is stable during testing;
5) Recording temperature measurement data;
6) The temperature is reported every day, and the technical part makes statistics and data arrangement, and reports and manages; when the temperature measurement data is abnormal, after the problem of temperature measurement equipment is eliminated, a layer of geotextile should be additionally covered for controlling the temperature difference in an emergency way.
The beneficial effects of the invention are as follows: according to the technical scheme, the application provides a construction method of the radiation-proof concrete structure of the medical room, and brick molding bed specifications and masonry construction engineering quantities are controlled according to foundations of different depths; for the super-thick raft, the outer wall and the top plate of the room area for the function, a reinforcing steel bar binding construction method and a erection method of a reinforcing steel bar engineering support frame body are provided, so that the stability and safety of the whole reinforcing steel bar plate surface are ensured; for the control of the structural construction joint, only one horizontal construction joint is reserved from the bottom plate to the top plate, and the rest ensures the integral molding; the template supporting system and the reinforcing of the wall body and the top plate are reasonably arranged in combination with the requirements of the demonstration situation of the dangerous engineering scheme, so that the stability and the safety of the template engineering are ensured; the construction scheme of integral construction is provided for concrete engineering, the aspects of large-volume concrete parameter proportion, casting construction sequence, casting process control, maintenance after casting, temperature control after casting and the like are controlled, the concrete forming quality is strictly controlled, and the radiation protection function of the functional house is ensured.
The invention combines the internal environmental conditions of the construction site, and starts from three main working procedures of the foundation, the reinforcing steel bars of the wall body top plate structure, the templates and the concrete, thereby specifying the specific requirements of each working procedure, achieving the specific steps of each working procedure target, each safety technical measure and meeting each quality control standard of the using function. The invention can provide a set of completed construction method for the subsequent medical radiation-proof structural engineering and similar structural engineering construction, and the whole quality is safe and controlled.
Drawings
The invention is described in further detail below with reference to the attached drawings and embodiments:
FIG. 1 is a schematic illustration of a construction joint set-up;
FIG. 2 is a schematic diagram I of basement wall construction joint formwork erection;
FIG. 3 is a second schematic view of basement wall construction joint formwork erection;
fig. 4 is a schematic view of a diagonal strut arrangement.
Fig. 5 is a schematic diagram of the arrangement of the reinforcement braces of the foundation raft.
Fig. 6 is a schematic diagram of the arrangement of the reinforcing steel bar support of the foundation pile cap with a larger area.
Fig. 7 is a schematic diagram of a temperature measuring point arrangement.
FIG. 8 is a second schematic illustration of a temperature measurement point arrangement.
FIG. 9 is a schematic view of the basement exterior wall water stop screw before installation and removal.
FIG. 10 is a schematic view of the basement exterior wall water stop screw after installation and removal.
Fig. 11 is a plan view of a support frame.
FIG. 12 is a section view taken along line 2-2 of FIG. 11.
FIG. 13 is a section view taken along line 3-3 of FIG. 11.
Fig. 14 is a first elevation view of the diagonal members of the support frame at intervals of 2 spans.
Fig. 15 is a second elevation view of the diagonal members of the support frame at intervals of 2 spans.
Fig. 16 is a construction view of a machine room roof reinforcement support.
Fig. 17 is a schematic diagram of a method for pouring a basic mass concrete slope layer by layer.
Fig. 18 is a schematic diagram of a method of pouring a mass concrete block and layer on a foundation.
Fig. 19 is a schematic view of a block casting direction and a blanking point.
Fig. 20 is a schematic view of a concrete pouring large direction.
Fig. 21 is a schematic diagram of a spray pipe arrangement.
Fig. 22 is a plan layout view of a condenser water tube arrangement.
Fig. 23 is a cross-sectional view of a condenser tube arrangement.
FIG. 24 is a schematic diagram of a sensor head arrangement.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the embodiments of the present application, are within the scope of the claimed invention.
According to the construction method of the radiation-proof concrete structure of the medical room, according to the field construction arrangement, a ward building is a first-open area excavated by earthwork, a linear accelerator machine room and a block where the linear accelerator machine room is located are excavated at first, foundation pile head breaking, cushion layer construction, brick mold construction and waterproof construction are arranged immediately, raft boards of the machine room and a basement bottom plate of the block are synchronously constructed, and construction joints are reserved at wall parts. After the bottom plate construction is completed, working procedures such as upper frame body erection, wall steel bar binding, template installation, top plate steel bar binding and the like are started, the wall steel bars, templates and back-roof reinforcement are required to be completed before the top plate template construction, finally, the top plate and the block structural plates are synchronously poured at one time, no wall top construction joint or in-plate construction joint is reserved, and finally, the radiation therapy machine room area structure construction is completed.
The whole construction process flow comprises the following steps: a first part: and (3) foundation slab structure construction: the method comprises the steps of earth excavation, concrete cushion layer, waterproof and protective layer, baseboard reinforcement binding, embedded part, baseboard concrete pouring and baseboard concrete maintenance;
a second part: construction of a wall and roof structure: the method comprises the steps of binding wall steel bars, installing embedded parts in the wall, checking and accepting, installing wall templates, installing opposite-pull screws for reinforcing templates, erecting a support frame, installing a top plate template, binding plate steel bars, installing the embedded parts, checking and accepting, casting the wall, and maintaining the top plate concrete.
The construction deployment arrangement is mainly used for realizing the construction method of the large-volume ultra-thick radiation-proof concrete structure for the medical room, the technical flow arrangement of construction is cleared, and a guiding thought is made for subsequent concrete construction.
Constructing foundation slab structural steel bars and template engineering;
first, measure construction
(1) And carrying out plane control by using a total station and a theodolite according to the coordinate control points and the elevation reference points provided by the construction unit, and carrying out elevation guiding measurement by using the level meter.
(2) And setting a deep coordinate point in the construction area according to the requirement according to the coordinate control point provided by the construction unit, and building a site control network by using the deep coordinate point. And a certain point in the plane control network is used as a measuring point (meeting the requirements of sight and convenience) for rechecking the site control network.
(3) The elevation is based on a level point provided by the construction unit. The value is based on the latest provided value of the construction unit. Construction Gao Chengying is adjusted in time according to the latest data.
(4) The measuring instrument is selected from
The measuring instrument used in the engineering mainly comprises a total station, a theodolite, a level gauge, a steel ruler and a tower ruler. Each instrument should be qualified and within a useful life. In the use process, the common index of the instrument should be checked frequently, and once the deviation exceeds the allowable range, the measurement accuracy should be corrected in time.
(5) Control of measurement accuracy and error range
(1) Angle measurement: adopting a back measurement method, wherein the error in the angle measurement is within 2' and the total error is within 2 mm;
(2) Distance measurement: measurements were made with an identified steel tape.
(3) The deviation between the axes of each layer is within 5mm, the vertical deviation of the layer height is within 5mm, and the vertical deviation of the total height is within 30 mm.
(II) excavating residual soil
And (3) at the position 300mm away from the designed elevation of the substrate, a horizontal line is cut out, small wood piles are nailed, and then the temporary soil layer is dug away manually. And after the substrate is repaired and leveled, quality inspection and acceptance are carried out. After digging to the designed elevation, timely notifying construction, investigation, design and supervision units of the groove inspection, forming groove inspection records, and immediately constructing cushion layer concrete after the groove inspection is qualified.
(III) pile head treatment
(1) And (5) ejecting a cutting control line at a position 20mm above the pile top design elevation.
(2) A hand-held cutting machine is used for cutting a circle along the control line, and the cutting depth is preferably not contacted with the main rib.
(3) And stripping the main reinforcement by using an impact drill and a pneumatic pick, then breaking pile core concrete by using the pneumatic pick or a hammer and a kettle, and finally, chiseling and flattening the pile top by using the kettle.
(4) The pile head main rib of the filling pile should be corrected and the anchoring length is ensured. The main rib is strictly forbidden to be cut off, and no straight bending exists.
(5) Pile head waterproof reference method: the pile top and the periphery are coated with cement-based waterproof paint, the surface of a cushion layer around the pile is coated with a width not less than 200mm, the closing-in position of coiled materials around the pile is sealed by waterproof ointment, and a water-swelling water-stopping ring is arranged at the root of a pile main reinforcement.
(IV) foundation formwork construction
Brick die: autoclaved aerated concrete blocks 600mm by 200mm by 240mm, concrete solid brick blocks 240mm by 115mm by 53mm, and the two brickwork are mainly used for building super-high foundation bearing platform, elevator shaft and water collecting well retaining brick mould. When the masonry height is 1200 < H and less than or equal to 2000, autoclaved aerated concrete blocks 600mm by 200mm by 240mm or solid bricks are adopted for masonry, and the thickness is 200 thick; when H is more than 2000, the parts below two meters are built by adopting concrete solid brick blocks 240mm 115mm 53mm, and the parts are built by adopting autoclaved aerated concrete blocks or solid bricks. When the wall length is greater than 2.5m, 500mm brick columns are additionally arranged, and when the wall height is greater than 4m, 300 mm 200mm concrete ring beams are additionally arranged.
Prefabricated fetal membrane of finished concrete: the specification is 3000mm multiplied by 600mm multiplied by 90mm, and the length can be customized according to the requirements. The method is mainly used for a conventional rectangular bearing platform soil-retaining side template or a ground beam side template, wherein the soil-retaining height H is less than or equal to 1500, and H is less than or equal to 1200, and a single-layer soil-retaining precast concrete bed-jig or solid brick is adopted for masonry.
(1) And after the cushion layer construction is completed, popping up the bearing platform foundation positioning line.
(2) And installing a finished brick moulding bed along the marked line, and fixing the finished brick moulding bed through a reinforcing steel bar head.
(3) The tire membrane seam is reinforced through the templates and the battens, so that the flatness and stability of the tire membrane seam are ensured.
Backfilling earthwork before removing the inner support, and binding the earthwork on the steel bars by using iron wires to strengthen the periphery.
And the inner support can be dismantled and reinforced after the waterproof cushion layer is poured.
And (3) reserving an outer wall construction joint: continuously pouring the wall body and the top plate at one time, and reserving a construction joint between the bottom plate and the outer wall at the position of 300mm in elevation; the construction joint is reserved as shown in figure 1, and basement wall construction joint templates are supported as shown in figures 2 and 3;
(V) binding of reinforcing steel bars
1) The process flow comprises the following steps:
binding beam steel bars, placing a beam bottom cushion block, binding a bottom plate steel bar, placing a plate bottom cushion block, discharging a wall column position line on the steel bar, installing wall column dowel bars, reserving and embedding water and electricity heating, self-checking, mutual checking, handover checking, reporting, supervision and acceptance checking.
2) Binding the reinforcing mesh. The intersection points of two rows of the reinforcing steel bars around the unidirectional stressed reinforcing steel bars are firmly tied at each point, the intersection points of the middle part can be tied in an intersecting way, and the reinforcing steel bar net of the bidirectional main reinforcing steel bar is firmly tied at all reinforcing steel bar intersection points.
3) The bottom plate reinforcing steel bar adopts double-deck reinforcing steel bar net, should set up reinforcing bar split heads, reinforcing bar support or angle steel support between upper and lower floor's reinforcing steel bar net to guarantee that the reinforcing steel bar position is correct. The hooks of the lower layer of steel bars face upwards, and the hooks of the upper layer of steel bars face downwards.
4) The blind column is connected with the foundation by the inserted bars, and the bending sections at the tail ends of the inserted bars are firmly fixed with the bottom plate steel bars.
5) The detailed view of the construction of the basement bottom plate is shown in pages 90-93 of the national standard atlas 16G01-3 flat plate type foundation chapter; the steel bars of the bottom plate should extend to the outer edge of the bottom plate, and the side edge structure of the bottom plate is constructed according to U-shaped steel bar structure edge sealing mode.
6) The plate construction method is described in detail in the national standard chart 16G101-1 except for the person noted in the figure.
7) The long-direction reinforcing steel bars of the bottom plate of the plate are arranged above the short-direction reinforcing steel bars; the long negative ribs of the plates at the support are arranged below the short negative ribs. The length of the plate bottom ribs extending into the beam support is more than or equal to 10d and exceeds the center line of the beam.
8) When the bottom of the plate is level with the bottom of the beam, the lower rib of the plate is bent near the beam edge according to the gradient of 1:6 and then stretches into the beam and is arranged on the longitudinal rib at the lower part of the beam.
9) The holes on the plate are reserved, only the holes with the hole size more than 300mm are shown in a general structural plan, all holes are reserved according to the cooperation of each professional drawing in civil engineering in various industries during construction, when the hole size is less than or equal to 300mm, reinforcing steel bars are not additionally arranged on the hole edges, and the reinforcing steel bars in the plate are bypassed by the hole edges and cannot be cut off. When the size of the hole is more than 300mm, the reinforcing method of the holes on the plate is as follows except for the person noted in the figure
10 The slab reinforcement is not cut off at the equipment pipe well where the concrete slab is required to be plugged, and after the equipment pipe is installed, the compensation shrinkage concrete casting with the strength grade not lower than that of the slab concrete on the same floor is adopted.
11 When the pipeline is embedded in the plate, the pipeline is placed between the plate bottom and the plate top steel bars, and the outer diameter of the pipeline is not more than 1/3 of the plate thickness. When the pipelines are arranged in parallel, the horizontal clear distance between the pipelines is not less than 3d (d is the pipe diameter). When the pipelines are crossed, the thickness of the concrete protection layer of the pipeline at the crossing part should not be less than 25mm.
12 Exposed cast-in-situ reinforced concrete parapet, hanging plate, breast board, and Seriola, when the horizontal straight line length exceeds 12m, the guide slits should be arranged, the distance between the guide slits is not more than 12m, the slit width is 20mm, and the drawing is pressed.
13 Double-layer bidirectional additional reinforcing steel bar meshes are additionally arranged at external corners of walls or beams of each floor roof abnormal plate, and when the cross floor is double-layer bidirectional through length reinforcing steel bars, if the spacing between the reinforcing steel bars at the plate corners does not meet the requirements, C8 short bars can be additionally arranged to meet the spacing requirements. The radiation ribs are additionally arranged at the plate surface of the external corner of the roof cornice cantilever plate, as shown in the following figure.
14 The graph is pressed when the different-height plate reinforcement structure has no specific requirement on the graph construction.
15 Except for the noted ones, the length of the negative ribs is calculated from the middle support, and the edge supports are calculated from the outer sides of the beams.
16 Foundation mat reinforcement bracket arrangement principle):
the thickness of the bottom plate is 700mm (C20@150 double-layer bi-directional) except the indication; the height of only one basement floor thickness is 500mm (C18@150 bi-directional) unless noted.
(a) The steel bar support columns are arranged in a groined manner, a C20 steel bar pull rod is horizontally added to the middle of each column at the position of a local pit (such as an elevator foundation pit, a water collecting well and the like), the bottom plate beams with the thicknesses of 700mm and 500mm are all C22 steel bars, and the columns are respectively C20 steel bars and C16 steel bars;
(b) As shown in fig. 4, the diagonal braces C16 are not oriented in the same direction and are arranged at a certain interval from left to right;
17 Basic raft steel bar bracket arrangement principle):
(a) The steel bar support upright posts are arranged in a groined manner, and a C20 steel bar pull rod is horizontally added to the middle of the upright post at the position of a local pit (the position of an elevator foundation pit, a water collecting well and the like):
(b) As shown in fig. 5, the diagonal braces should not be oriented in the same direction and are arranged at left and right intervals;
(c) The figure is applicable to raft h=2200 mm (20@150) rebar scaffold arrangement;
18 A large-area foundation pile cap reinforcement bracket arrangement principle;
(a) The steel bar support upright posts are arranged in a groined manner;
(b) As shown in fig. 6, the diagonal braces should not be oriented in the same direction and are arranged at left and right intervals;
(c) The drawing is suitable for the arrangement of the reinforcing steel bar bracket with a larger area of bearing platform h=2100 mm (25@100);
(d) And when the height of the bearing platform is greater than 2m, a C12@200mm reinforcing steel bar net is arranged in the middle of the height of the bearing platform.
Step (six) summary: the construction method mainly aims to realize the construction of the base plate steel bars and the formwork engineering in the construction method of the large-volume ultra-thick medical house radiation-proof concrete structure, and combines project characteristics to formulate a foundation formwork construction method and a steel bar construction method so as to prepare for hidden engineering construction before concrete pouring.
2. Constructing foundation concrete engineering;
construction requirements (one)
1) Basement bottom plate adopts inclined plane layering to pour, follows "inclined plane layering, and a slope (pumping concrete is 1: 6-1: 10 The thin layer covering and progressive principle, wherein the thickness of each layer is 500-600 mm, the layers are pushed from one side of the raft foundation to the other side, and then thin layers are poured and smashed in sequence and are topped once. The construction should be started from the lower end of the pouring layer, and the pouring layer gradually moves upwards so as to ensure the quality of concrete.
2) All pump pipes are supported in place, and each row of conveying pipes is fixed in point during pouring, and the responsibility is respectively negative.
3) The hose connected with the pump pipe or the front of the pump pipe is used for directly distributing materials on the surface of the bottom plate epithelial steel bar, and the hose is used for moving left and right to spread concrete in a fan shape on the premise of ensuring that the concrete is not cold-sewn, so that the spreading area of the concrete into the mold is increased as much as possible to increase heat dissipation and heat exchange.
4) The time for covering the poured concrete must not exceed the initial setting time of the concrete so as to avoid cold joints.
5) According to the range of concrete flowing speed of the large-volume foundation slab, the construction of pumping concrete in the elevator shaft and the water collecting pit is needed to be carried out in advance, and the concrete is compacted by vibrating. And pouring the concrete of the elevator shaft and the water collecting pit to be level with the large bottom plate, and tightly connecting the concrete part of the elevator shaft and the water collecting pit with the concrete part of the foundation bottom plate.
6) The concrete in the elevator shaft and the water collecting pit adopts an intermittent pouring method, the templates are made into a whole and erected in advance, the concrete is poured to be flat with the templates, when the mobility of the pit bottom concrete is not large and the pit wall concrete pressure can be born, the pit wall concrete is poured again, and the quality of the contact position of the bottom and the wall is ensured. The intermittent time is about 2 hours.
7) The pit bottom pouring sequence is pushed from one end to the other end in the length direction, or from two ends to the middle. The pit wall should form a loop and pour layer by layer. When the concrete on the side wall of the water pit is poured, a symmetrical pouring method is adopted, so that the uniform stress of the side wall template is ensured.
8) And (3) after the concrete is poured and is coated and pressed for the first time, covering and curing are started, and a curing method of heat preservation and moisture preservation is adopted.
9) The covering method comprises the following steps: the bottom plate adopts a method of 'single-film single-layer geotextile', namely a layer of heat-preservation gunny bag is covered on a layer of plastic film; the side wall adopts a method of 'single-film double-layer geotextile', namely, a layer of plastic film is covered with two layers of heat-insulating geotextile. The heat-insulating geotextile is covered outside the side mould, so that the moisture and hydration heat on the surface of the concrete are not lost, the internal and external temperature gradients of the concrete can be reduced, the internal and external temperature differences of the mass concrete are ensured, and the strength of the concrete is increased and the crack control of the concrete is facilitated. The plastic cloth is covered and maintained without watering during heat preservation, so that the surface temperature is prevented from falling too fast, the covering tightness of the plastic cloth is ensured, the lap joint is not less than 200mm, bricks and square timber are pressed, and the side wall is fixed by element nails. The curing start time is when the surface strength can be on person. The plastic cloth must not be uncovered at will during curing to perform other operations on the concrete surface.
10 During curing and temperature measurement, the highest temperature, the surface temperature and the atmospheric temperature of the concrete at each temperature control point are provided in time, so that the on-site heat preservation and curing are guided, the heat dissipation of the heat preservation layer is reduced at the midday and the afternoon to shorten the heat preservation and curing time, and the heat preservation and curing time is covered again at night.
11 Heat preservation time: and according to the temperature measurement record, when the temperature of the concrete center begins to drop and approaches to the surface temperature, and the temperature difference between the temperature of the concrete center and the temperature of the atmosphere is less than 25 ℃, the heat preservation is started to stop. The plastic film and the heat preservation gunny bag are removed layer by layer, and each layer is removed and kept at a certain time interval according to the measured temperature so as to avoid generating larger temperature gradient.
12 According to the actual measurement data, firstly removing the upper heat preservation layer, then completely removing the heat preservation layer, and carrying out watering maintenance for at least 14 days.
13 The engineering large-volume concrete structure is a rectangular structure, temperature measuring points are arranged on the most unfavorable section of the whole basic temperature, rectangular diagonal positions are arranged on the long sides of the rectangle, 4 points are symmetrically arranged on the half sides of each most unfavorable axis, one temperature measuring point is arranged on the center of a plane for the large-volume structure with smaller size, three temperature measuring points are arranged along the thickness direction of the structure, and the arrangement schematic diagrams of the temperature measuring points are shown in figures 7 and 8;
step two, summarizing: the method mainly aims to realize the construction of the machine room bottom plate concrete engineering in the construction of the large-volume ultra-thick medical room radiation-proof concrete structure, and the foundation raft structure is relatively regular, and mainly aims to control the concrete pouring process and maintain the concrete, so that the bottom plate structure is prevented from cracking and other quality problems caused by temperature change through temperature control measures and maintenance methods.
3. Constructing a wall and a roof structure steel bar and a template engineering;
firstly, measuring paying-off (working with foundation structure construction measuring paying-off);
binding wall steel bars;
1) The process flow comprises the following steps:
the method comprises the steps of a root construction joint treatment, vertical steel bar lap joint and welding, inspection of a welded joint, binding of column stirrups, binding of non-waterproof wall steel bars, cement stay placement, water heating reserved embedding, self-inspection, mutual inspection, handover inspection and acceptance reporting.
b, processing a root construction joint, overlapping and welding vertical steel bars, checking a checking welding joint, binding column stirrups, binding waterproof wall steel bars, reserving and embedding water and electricity heating, installing a protective layer cushion block, self-checking, cross-checking, and checking and accepting report supervision.
2) The hidden column stirrups are perpendicular to the stressed bars, the overlapping positions of the hooks are staggered and bound along the direction of the stressed bars, the crossing points of the corners of the stirrups and the longitudinal steel bars are firmly bound, the binding buckles are splayed when the stirrups are bound, the stirrups are flat, the opposite angles of the openings are staggered and spirally bound, the specification interval is according to the drawing, and the tail parts of the binding wires face to the column centers of the walls.
3) When the section of the wall column is changed, the bending part of the reinforcing steel bar must be within the height of the beam column wall node.
4) The connecting beam steel bars are arranged on the inner sides of the longitudinal steel bars of the wall columns.
5) The reinforcing steel bar net of the wall is bound with the foundation, and the hooks of the reinforcing steel bars face to the inner side of the wall column.
6) The construction methods of the horizontal steel bars, the vertical steel bars, the edge members, the connecting beams, the hole reinforcements and the like of the shear wall body are all shown in pages 71-83 of the national standard chart set 16G101-1 except the points noted in the figures.
7) Except the person noted in the figure, the shear wall body is double-layer bidirectional reinforcement, and the vertically distributed reinforcement is on the inner side, and the horizontally distributed reinforcement is on the outer side.
8) The diameters and the intervals of the lacing wires are specifically marked in the drawing, the lacing wires are arranged in a plum blossom manner, and the detailed method is shown in the 16 th page of the national standard chart set 16G 101-1.
9) The horizontal distribution steel bars of the wall limbs in the height range of the shear wall connecting beam are used as waist bars of the connecting beam in the connecting Liang Nala. Except for the condition of the additional steel bars, only the horizontal steel bars of the shear wall can be pulled through to serve as the connecting beam waist steel bars.
10 The construction method of the shear wall restraining edge member is shown in pages 75 and 76 of national standard chart set 16G 101-1.
11 The holes on the wall must be reserved and the holes must not be chiseled later. For discontinuous small holes, and when the length of each side is less than 800mm, the drawing is pressed for reinforcement unless noted otherwise.
12 The allowable deviation of the formwork and the wall body of the shear wall is required to be strictly executed according to the relevant regulations of construction acceptance regulations, concrete is required to be poured in layers, the pouring heights of the first layer and each layer later are respectively not more than 500mm and 1000mm, and the interface surface is required to be cleaned completely, so that good combination of the concrete is ensured.
13 The specification, the size, the spacing, the row spacing, the lap joint length, the anchoring length, the thickness of the protective layer and the like of the wall steel bars meet the design and specification requirements.
14 The binding of the steel bars is firm, all the crossing points should be bound, and the binding buckle should face to the inner side. The positions of the binding overlap joints of the reinforcing steel bars are staggered, the staggered distance meets the requirement, and three binding buckles and three horizontal ribs are ensured to pass through in the binding overlap range of the vertical ribs of the wall body.
15 The wall body drag hook is bound on the crossing point of the horizontal and vertical steel bars, the distance is taken according to a 16G101 chart set and a drawing, binding is arranged at the overlapping position of the hooks in a staggered mode along the direction of the stressed bars, and the bound drag hook is clamped by a tool type clamp and then bent, so that the arrangement distance of the steel bars is unchanged.
16 A top mold rod for fixing the gate, a steel bar for fixing the box and a grounding wire are tightly forbidden to be welded on the stressed steel bar.
17 Wall measure reinforcing steel bar): in order to ensure that the double-layer steel bars of the wall are horizontal and vertical, the distance is uniform and correct, and vertical ladder bars are used for limiting. In order to ensure the thickness of the wall, a short steel bar internal support is added at the opposite-pull screw rod, the two ends of the short steel bar are smooth, and antirust paint is brushed. And after the wall reinforcements are bound, correcting the positions of the main reinforcements of the door and window opening nodes to ensure the thickness of the protective layer. The number of the binding threads of the wall body steel bar lap joint is not less than 3, and the binding threads are inwards.
(III) wall form installation
1) And (3) positioning and lofting the wall profile before installing the wall template, and alternately installing the template and the batten at one time until the whole wall is installed. Before the template is installed, the positions of the opposite-pulling screws are calculated, holes are formed according to the specified intervals, and for the inner wall, the template can be installed first and then the screws are placed for reinforcement; for the outer wall, a counter-pulling water stop screw rod is arranged before the formwork is installed and erected, and then the whole reinforcement is carried out; as shown in fig. 9 and 10;
2) When the loose-splice shaping template is used for supporting the template, the template should be carried out from bottom to top, and the upper layer of the template can be installed after the lower layer of the template is completely fastened. Temporary fixing measures should be taken when the lower layer cannot be independently provided with the supporting members.
3) When the prefabricated large wall templates are adopted for formwork erection, 2 templates are strictly forbidden to be lifted at the same time, and the templates are positioned, corrected and connected at the same time, and the fixed templates can be unhooked.
4) Before installing the elevator shaft inner wall mould, a layer of scaffold board must be firmly fully laid at the position 200mm below the board bottom.
5) Before the split bolts are not installed on the templates, the plate surface should be inclined backwards by a certain angle.
6) When the length of the steel ridge needs to be lengthened, the same number of steel ridges with the same specification or not less than the original specification are added at the joint, and the lap joint length of the steel ridge is not less than 15% -20% of the width or the height of the wall template.
7) The U-shaped cards are required to be installed in a positive and negative alternate mode during splicing, and the distance is not more than 300mm; the U-shaped cards at the butt joint joints of the 2 templates are fully assembled.
8) The split bolts are vertical to the wall templates, the tightness is consistent, and the wall thickness is correct.
9) The internal and external supports of the wall form must be firm and reliable, and the overall stability of the form should be ensured. When the outside of the wall form cannot be provided with the support, the inside of the wall form is provided with the support capable of bearing the tensile force and the compressive force. When the wall templates are integrated with the support, measures should be taken to prevent adjacent templates from deforming when concrete is poured.
10 Wall support reinforcing calculation parameters are shown in the following table:
the specific erection parameters of the shear wall are shown in the following table:
(IV) supporting the frame body, as shown in figures 11-13;
1. parameters for setting up frame body
1) Material property and parameter table
2) Frame body setting up parameter meter
2. The frame body is erected
(1) Construction process flow
Paying off and checking, setting up a full framing, paving a steel pipe main keel, paving a wood glue board surface layer, self-checking and checking.
(2) Construction of vertical and horizontal rods
1) Lap joint requirements: all the upright posts at all parts of the project are connected by connecting sleeves, and overlap joint is forbidden.
2) The upright rod connecting sleeve can be a cast steel sleeve or a seamless steel tube sleeve. The length of the vertical rod connecting sleeve in the form of cast steel sleeve is not smaller than 90mm, and the insertable length is not smaller than 75mm; the length of the vertical rod connecting sleeve in the form of a seamless steel pipe sleeve is not smaller than 160mm, and the insertable length is not smaller than 110mm. The gap between the inner diameter of the sleeve and the outer diameter of the upright steel pipe is not more than 2mm.
3) The vertical rod and the vertical rod connecting sleeve are provided with anti-extraction pin holes for fixing the vertical rod connecting piece, the aperture of the pin holes is not more than 14mm, and the allowable size deviation is +/-0.lmm; the diameter of the pole connection is preferably 12mm, and the allowable dimensional deviation is + -0.lmm.
4) At the position where the bottom of the vertical rod is not higher than 500mm from the ground, the floor sweeping rod is arranged along the longitudinal and horizontal directions according to the procedure of longitudinal and transverse directions.
5) The horizontal rods in the longitudinal and transverse directions of each step are connected and pulled through the disc buckle nodes;
6) Before the vertical rod and the horizontal rod are erected, the beam slab rod piece is required to be measured and paid off according to the erection requirement, the vertical rod point position is required to be rechecked after the paying off is finished, and the rod piece can be erected according to the requirement.
(3) Adjustable base and jacking
1) The screw rods of the adjustable base and the adjustable bracket are preferably trapezoidal teeth, the A-shaped upright rod is preferably provided with a 48 screw rod and an adjusting handle, and the outer diameter of the screw rod is not less than 46mm; the B-type upright rod is preferably provided with a 38 screw rod and an adjusting handle, and the outer diameter of the screw rod is not smaller than 36mm.
2) The bottom plate of the adjustable base and the adjustable bracket supporting plate are preferably made of Q235 steel plates, the thickness of the adjustable base and the adjustable bracket supporting plate is not smaller than 5mm, the allowable dimensional deviation is 2mm, and the length and the width of the steel plates of the bearing surface are not smaller than 150mm; the steel plate of the bearing surface and the screw rod are subjected to ring welding, and stiffening sheets or stiffening arches are arranged; the adjustable bracket supporting plate is provided with an opening baffle, and the height of the baffle is not less than 40mm.
3) The screw rod and the nut of the adjustable base and the adjustable bracket are not smaller than 5 buckles, the thickness of the nut is not smaller than 30mm, the cantilever length of the adjustable bracket of the template bracket extending out of the top level rod or the double-groove steel joist is strictly forbidden to exceed 650mm, the exposed length of the screw rod is strictly forbidden to exceed 300mm, and the length of the adjustable bracket inserted into the vertical rod or the double-groove steel joist is not smaller than 150mm.
4) The exposed length of the adjusting screw rod of the adjustable base of the plate bracket is not more than 300mm, and the ground clearance height of the horizontal rod at the bottommost layer serving as the sweeping rod is not more than 550mm.
(4) Diagonal bar and scissors stay arrangement
1) When the template support in the high formwork supporting area is erected, the vertical diagonal rods are required to be arranged according to the standard requirement, the step distance of the horizontal rods is not more than 1.5m, and the steel pipe fastener scissor supports are required to be arranged at intervals of 4-6 standard step distances along the height. When there is a structure around, it is preferable to form a reliable drawknot with the surrounding structure.
2) When the template support is set up into an independent tower-shaped support without lateral drawknots, each lateral surface of the support body is provided with a vertical diagonal rod at each step. When the torsion prevention requirement exists, a horizontal layer diagonal rod or a steel pipe horizontal scissor stay is additionally arranged on the top layer at intervals of 3-4 steps.
3) The steel pipe scissor stay should adopt rotatory fastener to fix on the pole setting or the horizon bar that intersect with it, and the distance should not be greater than 150mm of rotatory fastener center to main node. The slenderness ratio of the scissors is not more than 200.
4) The knife support should adopt overlap joint when lengthening, overlap joint length should be not less than 1000mm to should set up not less than 2 rotatory fasteners, and both ends fastener should be in from the pole end not less than 100mm department fixed.
5) The knife rest should be set up synchronously with the vertical rod and the horizontal rod in the longitudinal and transverse directions, and cannot be installed in a lagging way.
6) The horizontal scissors support needs to simultaneously tie the column frame body and the beam area frame body.
7) The standard type support frame body is adopted by the project frame body, and the design value of the axial force of the vertical rod is within 40 KN. The specific arrangement requirements of the vertical diagonal rods are as follows:
note that: 1) The vertical shaft axial force design value and the scaffold setting height are the maximum value in the unified independent frame;
2) Each span represents that the vertical diagonal rod is erected along the longitudinal direction and the transverse direction; the first span is the vertical diagonal rods are erected at intervals of 1 span along the longitudinal direction; interval 2 spans, 3 spans, and so on. As shown in fig. 14 and 15; 1-standing a pole; 2-horizontal bars; 3-vertical diagonal rods;
(5) Non-conforming spacing modulus adjustment
1) When the moduli do not match, an adjustment span is set at the plate location.
2) The adjusting span is arranged at the position with smaller bearing load under the plate, and is integrally formed by pulling the steel pipe with a common fastener at each step.
3) The horizontal rod extends to the pole setting of at least 2 design supports of lock joint to both ends.
4) Gaps with different distances exist in the erecting process of the Liang Banjia body, steel pipes are needed to be connected in a drawknot mode every span, and the connecting fasteners are connected to the vertical rods in a drawknot mode.
Fifth, roof form installation
1) The form must be sealed after the reinforcement is approved for concealed acceptance.
2) Template mounting sequence: vertical structural mold, beam mold and platform mold. After each single template is finished, the single template can be transferred to the next working procedure after self-checking and technical rechecking. When the vertical structural mold is rechecked, the upper port elevation must be rechecked.
3) Carefully check the quality of the entry form, the wood form requires the use of a perfect splint. Various templates are required to be solid, flat and perfect. The size of the processing template needs to be checked.
4) And ejecting all the beams, columns and wallboard edges according to the turnover diagram. The form must be precisely aligned. The wallboard and the column are limited by welding the steel bars under the wall bars and the column bars.
5) Before installing the template, checking the positions, the sizes, the specifications, the number and the fixing conditions of the embedded parts and the reserved holes. And the method is coordinated with an installation unit, and the pipeline in the wall is ensured to be installed before the template is sealed.
6) Before the column and the wallboard mould are sealed, garbage and sundries in the mould are cleaned, and the floating ash is cleaned by compressed air.
8) The elastic wire vertical bent is required to be horizontal and vertical. The perpendicularity and the interval of the upright posts, the arrangement of the scissors supports and the arrangement of the joints when the upright posts are lengthened are in accordance with the scheme requirements.
9) The net span of the short side of the floor is more than or equal to 4m, and the arch starting value of the center of the floor is 2/1000 net span; the cantilever plate has a cantilever length of more than or equal to 1.5m, and the cantilever section end arching value is 4/1000 of the cantilever length. The span of the beam is more than or equal to 4m, and the span arch value of the beam is 1/1000-3/1000 net span; the beam span is more than or equal to 9m, and the arch starting value in the beam span is 1/500 net span.
10 The beam and column node templates have clear relationship and firm fixation. The joint part is inlaid by a 50mm thick wood die, and the thin plate is forbidden.
11 Flatness control and slurry leakage prevention operation points:
the side dies of the beam and the wallboard are arranged in staggered joint, the templates are tightly spliced, and the joint is stuck with a box sealing paper tape.
Before installing the column and the wallboard bottom template, cleaning the root of the column and the wallboard, leveling the vertical template by using mortar to ensure that the elevation of the vertical template is consistent and prevent slurry leakage from the root.
The template at the construction joint part of the stair is provided with a cleaning opening, so that quality common problems such as slag inclusion and the like are avoided.
12 The steel pipe fastener transverse and vertical enclosing purlins and the opposite-pulling screw rods are strictly arranged according to requirements, the double-spliced transverse enclosing purlins are arranged in a unified length mode, joints are staggered, and hook head bolts are arranged according to the requirements of a turnover diagram so as to effectively control the section size of a component and strengthen the overall rigidity of a beam and a wallboard.
13 The long twine is pulled and fixed firmly with the bent frame when the side die is fixed.
14 The template is installed to be positioned correctly, supported firmly and the plate surface is flat. The special person takes charge of checking and rechecking.
Sixth, binding the roof steel bars
1) The process flow comprises the following steps: installing beam steel bars, sinking beams, correcting and arranging bottom surface and side surface steel bar protection layer cushion blocks, installing plate steel bars, arranging plate steel bar protection layer cushion blocks, reserving pre-buried mounting plate surface layer steel bars (upper layer steel bars if double-layer steel bars are adopted), supporting, arranging split heads, self-checking, mutually checking, special checking, reporting, managing and checking.
2) The protection layers of the beam bottom and the beam side steel bars adopt mortar/concrete cushion blocks, the beam steel bars adopt overhead binding, and the beam is submerged by other equipment such as a hoist.
3) Bending the beam main reinforcing steel bars when the length of the horizontal section of the beam main reinforcing steel bars extending into the wall column is smaller than the anchoring length so that the beam main reinforcing steel bars meet the anchoring length; when the length of the horizontal section of the secondary beam extending into the main beam is less than 0.4La, the joint of the primary beam and the secondary beam should be respectively bent downwards and upwards; if the support meets the anchoring length of the main steel bars of the beam, the steel bars at the bottom of the beam should extend at least 5d beyond the axis. When two rows of beam main steel bars are arranged, a cushion block (the short steel bars with the thickness phi of 25) with the thickness not less than 25mm is arranged between the two rows of steel bars; the lap joint binding joints should be provided with three-point binding, and any joints must be staggered; the crossing point of the stirrup and the main bar must be bound at each point, and the end of the binding wire must be folded into the framework.
4) The intersection points of two rows of steel bars at the periphery of the unidirectional plate are all bound, the intersection points of the middle part can be indirectly bound, and the intersection points of the bidirectional stressed bars are all bound.
5) The plate hogging moment bar is positioned by adopting an I-shaped split heads which are arranged at the end parts of the hogging moment bar.
6) The steel bar connection mode comprises binding connection, mechanical connection and welding, and the engineering frame column longitudinal bars are preferably mechanically connected; the beam longitudinal reinforcement joint is suitable for avoiding a beam end stirrup encryption area, and mechanical connection cannot be adopted when avoiding; other parts can be bound; the steel bar diameter d is more than or equal to 22, and the longitudinal bars of the conversion beam are mechanically connected. The type and quality of each type of joint should meet the national standards.
7) Arranging a reinforcing steel bar support frame;
the thickness B=1600 mm of the top plate of the machine room, and the plate reinforcement C25@150mm is double-layer bidirectional; tie bars which are arranged in a C8@600 bidirectional quincuncial shape are arranged between two steel bar meshes in the wall body and the top plate of all the machine rooms; the anchoring of the vertical distributing ribs of all concrete walls in the bottom plate is constructed according to the method of page 64 (a) or (b) of the atlas 16G 101-3.
The construction diagram of the reinforcement support at the top of the machine room is shown in fig. 16.
(seventh) step summary: the method mainly aims at realizing construction of inner and outer walls, roof steel bars, templates, support frames and reinforcing systems of a machine room in construction of a large-volume ultra-thick medical room radiation-proof concrete structure, and mainly aims at quality control in the binding construction process of the surrounding side walls and the roof steel bars, reinforcing methods of templates with different wall thicknesses, setting up methods of supporting systems with different roof thicknesses in the interior, related working procedure construction flows and sequential lap joint relations. The reinforcement and the formwork engineering in the step are strictly arranged according to reinforcement parameters and formwork support parameters, the reinforcement structure has great influence on the integrity and durability of the whole structure, the formwork support is arranged in a subsection project with larger danger beyond a certain scale, and the whole safety and stability are controlled.
4. Reserved pre-buried construction
1) Linac equipment manufacturer technology represents field technology surrendering for reservations, pre-embedments, and provides the necessary reservations, pre-embedments and technical parameters for linac installation and use.
2) And (5) carrying out reservation and pre-embedding construction strictly according to the drawing and manufacturer requirements.
3) And after the reserved and embedded construction is finished, notifying the supervision and related units to check and accept, and making a hidden engineering record. The acceptance content comprises: the linear accelerator is installed in place and needs the position and specification of the pre-buried steel plate and the profile steel; the size, the installation height, the material and the specification model of the opening of the ventilating duct; reserved positions of the strong and weak electric tubes, materials and specification types of the materials; the embedded position and the material of the air conditioner pipeline; special requirements and practice of lightning protection and grounding, material requirements and the like.
5. Constructing a wall and roof structure concrete engineering;
firstly, constructing mass concrete;
(1) Concrete pouring
1) The integral and impervious performance requirements of the large-volume concrete foundation slab are high, concrete is poured continuously, and no construction joint is left;
2) Adopting a layered pouring method, wherein the layered pouring can be performed by adopting an inclined plane layering and a block layering method, and schematic diagrams of the inclined plane layering and the block layering are shown in figures 17 and 18;
Under the condition of ensuring continuous casting of each layer, the intermittent time between the layers is shortened as much as possible, and after the casting of the lower layer concrete is finished, the pipe is firstly disassembled and returned to the initial casting position, and then the upper layer concrete is cast, so that the continuity of the whole concrete casting process is ensured. The casting thickness of each layer of the large-area concrete is controlled to be about 500 mm.
3) Marking the vertical indicating rod before casting to mark the casting thickness of each layer. And during pouring, a pump pipe distributing machine is adopted, and each pump is responsible for one area. The total time of concrete transportation, pouring and intermittence does not exceed the initial setting time of the concrete. The construction sequence is reasonably arranged in construction, the concrete is controlled to uniformly rise in the casting process, the layered casting can fully radiate hydration heat of the lower layer concrete in the initial setting time, the heat storage capacity of the concrete can be reduced, the accumulation of the hydration heat is prevented, and therefore the temperature stress is reduced.
4) The free falling height is not more than 2m when the concrete is poured, and if the free falling height is more than 2m, a method of lengthening a hose and stringing barrels is adopted. There should be enough concrete in the hopper during pumping to avoid clogging by air intake.
(2) Concrete vibrating
1) After the concrete is put into the mould, the concrete is flattened and vibrated in place by an inserted vibrating rod.
2) In the pouring process, concrete vibration is an important link, the concrete vibration is strictly operated according to an operation rule, quick insertion and slow pulling are achieved, the quick insertion is used for preventing air bubbles in lower-layer concrete from being discharged after compaction of upper-layer concrete, and the slow pulling is used for enabling the concrete to fill up a cavity caused by a rod. In the vibrating process, the vibrating rod is slightly pulled up and down to enable concrete to be vibrated tightly, the insertion points are uniform, the distance between the insertion points is controlled to be 50cm, and the distance from the template is 20cm. The single row form is adopted, the concrete is not required to be mixed with the staggered type, so that vibration leakage is avoided, the vibration point time is well mastered, the vibration point time is not required to be too long or too short, and the concrete is generally controlled to be between 20 and 30 seconds until the surface of the concrete is flooded, no air bubbles appear, and the concrete is not sunk.
3) The vibrator must not collide with the reinforcing steel bars, the templates and the embedded parts during vibration.
(4) The intermittent time is correctly controlled in the pouring process, the upper layer concrete should be poured before the lower layer concrete is initially set, and when the upper layer concrete is vibrated, the vibrating rod is inserted 5cm downwards, so that the upper layer concrete and the lower layer concrete are better combined.
(II) concrete construction measures
(1) Technical measures
In order to ensure the construction quality of concrete engineering, the following measures are adopted:
1) In order to ensure that the concrete is not cracked, a water reducing agent is added into the concrete.
2) In autumn and winter, the average temperature of the Hangzhou is 17-25.3 ℃, and the concrete pouring should avoid weather. And controlling the surface temperature of the concrete to be not more than 30 ℃.
3) And (3) treating the concrete surface of the construction joint: the loose portion of concrete is roughened to expose the hard portion and is cleaned with water.
4) In the concrete pouring construction, attention is paid to the protection of reserved and embedded parts.
5) The management personnel should be trained professionally before construction, and technological communication should be carried out step by step, so that the management personnel are familiar with the important construction control points of the linear accelerator machine room. Meanwhile, a strict duty shift-on system should be established.
(2) Concrete temperature control and shrinkage crack pre-control measures
1) Concrete temperature control
In order to effectively control the occurrence and development of harmful cracks, measures are necessary to comprehensively consider in terms of controlling hydration temperature rise, delaying temperature reduction rate, reducing shrinkage of concrete, improving ultimate tensile strength of concrete, improving constraint conditions, designing construction and the like of the concrete.
2) Reducing the temperature of concrete entering the mould
The retarder is properly used in the concrete stirring engineering to prolong the initial setting time of the concrete, and the initial setting time is adjusted to 8-10 hours, so that the hydration heat peak is delayed, the internal temperature of the concrete is reduced, and the molding temperature of the concrete is controlled.
3) Cooling measure in concrete pouring process
The length of the concrete conveying pipe is reduced as much as possible, the elbow is reduced, so that the loss in the concrete slump conveying pipe is reduced, the concrete entering temperature is reduced, the concrete is poured in a slope layering and step-type propelling mode, the thickness of each layer of concrete pouring is reduced under the condition that cold seams are not formed, and the thickness of each layer is not more than 300mm, so that hydration heat is sufficiently dissipated in the pouring process, and the later hydration heat is reduced.
4) Preserving heat and moisture, and curing, and the following steps are detailed.
(3) Other pre-control measures
a. When the concrete is poured, the vibration is compact, so that the shrinkage is reduced, and the cracking strength of the concrete is improved. And the panel is smeared and pressed, and the secondary smeared and pressed can be carried out after the initial setting and before the final setting of the concrete, so that the tensile strength of the concrete is improved, and the shrinkage is reduced. And after concrete is poured, curing is carried out timely.
b. The surface of the concrete is subjected to heat accumulation and moisture preservation maintenance, so that the moisture in the concrete can be effectively sealed, the concrete can be maintained under the moist condition, the generation of shrinkage cracks is controlled, and the gunny bag is covered for heat preservation, so that the surface heat dissipation is reduced.
c. The moisture preservation maintenance can smoothly carry out cement hydration, improve the ultimate tensile strength of concrete, reduce temperature stress and shrinkage cracks on the surface of the concrete, and finally ensure that the temperature gradient of the internal and external concrete is within the allowable range of design and specification.
d. When the gunny bag is hung on the outer side surface and the inner side surface of the wall die, the gunny bag is covered by iron wires in a strip shape, the cover Yan Tieshi is fixed on the enclosing purlin, and the gunny bag is plugged in the wood baffle area grid. And during maintenance, intelligent spraying, heat preservation and moisture preservation are carried out for at least 14 days.
e. And during the heat preservation period, especially when the top plate is used for heat preservation, the linear accelerator chamber entrance door is closed, so that heat dissipation can be effectively prevented.
f. During the heat preservation period, the fire prevention safety work of the adjacent areas is required to be carried out, and the operation of smoke and nearby fire is strictly forbidden.
g. And the time for removing the heat preservation layer refers to the analysis result of the temperature measurement data of the mass concrete engineering. The concrete method is to remove the heat insulation material in layers, and forbid the construction personnel to remove the form in advance without permission.
(III) machine room large concrete construction sequence
And pouring concrete of the bottom plate, the wall body and the top plate in layers according to the height of each 300mm, pouring 1 day pump and 1 ground pump into 3 direct-adding machine rooms at the same time, and dividing the pouring range of each pumping mechanical equipment according to the arm length of the day pump and the concrete pouring experience of the bottom plate. And taking 3 pouring points for wall concrete, and pouring by the pumping mechanical equipment in a revolving way within a range. And 4, taking a pouring point every 4 meters of roof concrete, and pouring 3 pumping mechanical devices from two sides to the middle in a rotary manner within respective ranges. The casting direction and sequence are shown below.
Casting a beam slab column in a common area: firstly pouring and constructing a C50 structural column and a shear wall of a main building area, and then pouring a shear wall column of an inner and outer wall connecting area, wherein the connecting parts with different marks are required to be synchronously poured on two sides; the basement outer wall is poured in layers, the layering thickness is not more than 50 cm, and the construction cold joint is prevented from occurring by continuous pouring in place;
pouring in a linear acceleration machine room: synchronous pouring of the inner wall and the outer wall, layered synchronous pouring of different labels, taking joint parts of the inner wall and the outer wall as boundaries, pouring from far to near, and pouring impervious parts of the outer wall preferentially, wherein slurry is continuously removed in the process, so that concrete is not accumulated; the overall layered casting height is controlled at 30 cm. As shown at 19, 20.
(IV) mix design
(1) Concrete design requirements
1. Concrete expanding agent
1) The engineering basement structure is very long, and the expansion agent doped shrinkage compensating concrete is used for casting and tamping.
2) The adopted expanding agent meets the relevant technical requirements of specification regulations such as concrete admixture application technical regulations (GB 50119-2013), compensating shrinkage concrete application technical regulations (JGJ/T178-2009) and the like;
3) The material selection, mix design, construction, curing, quality inspection, etc. of the compensating shrinkage concrete should meet the specifications of the specific regulations, specifications or construction methods. The prepared compensating shrinkage concrete is required to be controlled to be maintained in water for 14 days, the requirement of limiting expansion rate is shown in the table, and a compensating shrinkage concrete mixing ratio test is required to be made before construction, so that the design requirement is met; the concrete expansion rate is limited during construction and is subjected to spot check.
4) Reference doping amount at the time of test: post-pouring belt, reinforcing belt-40-60 kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the The rest positions are-30 kg/m to 50kg/m 3
5) The expanding agent is not suitable for being used in combination with the chloride-type additive, and the expanding agent should be cautious when being used in combination with the antifreezing agent;
6) The expanding agent does not contain aluminum powder, and the alkali content is less than or equal to 0.75 percent;
7) The admixture such as silica fume, zeolite powder, limestone powder, kaolin powder and the like should be tested and demonstrated before the admixture such as foaming agent, accelerator, underwater non-discrete concrete admixture and the like is used together with the expanding agent.
2. Concrete externally-added anti-cracking fiber
1) The basement bottom plate, basement outer wall and top plate of the engineering require to be doped with polypropylene anti-cracking fiber 0.9kg/m 3 .
2) The geometrical characteristics and main physical and mechanical index requirements of polypropylene fibers: ,
shape: y-shape; diameter: 18-20 mu m; length of: 6 or 9mm of the diameter of the tube,
density of 0.91g/cm 3 The tensile strength is more than or equal to 400MPa;
the elastic modulus is more than or equal to 3500MPa, and the elongation at break is 15% -20%;
3) The fiber has chemical stability in the concrete mixture and hardened concrete, the strength is not reduced, the fiber is easy to disperse and uniform in the concrete mixture and cannot agglomerate; and has good bonding performance with hardened concrete;
4) When testing fiber concrete, the mixing proportion is determined according to common concrete without considering the influence of the fiber on the compressive strength of the concrete;
5) The fiber has alkali resistance, is not corroded by cement alkaline hydrate in concrete, and has chemical stability to concrete admixture.
(2) Concrete supply mix proportion design
The mass concrete used in this project is produced and supplied by commercial concrete mixing plants. The project department should carry out special mix proportion design with the concrete mixing station according to the characteristics of the mass concrete. Because the structural dimensions of the basement bottom plate and the wallboard of the linear accelerator machine room are large in difference, the proportion design is preferably carried out separately.
1) Ordinary silicate cement with low hydration heat should be selected, and the cement strength is not lower than 42.5Mpa. The 3d hydration heat is not more than 250kJ/kg, and the 7d hydration heat is not more than 280kJ/kg. The tricalcium aluminate content should not be greater than 8%.
2) The fine aggregate is preferably middle sand, the fineness modulus is preferably more than 2.3, and the mud content is not more than 3%; the sand ratio is preferably 38% -42%.
3) The non-alkali active coarse aggregate is selected, the particle size of the coarse aggregate is preferably 5.0-25 mm, the particle size of the coarse aggregate can be properly selected to be large on the premise of not influencing pumping construction, the coarse aggregate is continuously graded, and the mud content is not more than 1%.
4) The concrete is preferably doped with a certain amount of fly ash or granulated blast furnace slag powder to replace part of cement and reduce hydration heat. The class F class I or class II fly ash is preferably adopted, the mixing amount is not more than 50% of the dosage of the cementing material, the slag powder is preferably S95 grade, the specific surface area is not more than 420 square meters per kg, and the mixing amount is not more than 15% of the dosage of the cementing material; the total mixing amount of the fly ash and the slag powder is not more than 50 percent of the dosage of the cementing material.
5) Proper amount of additive is added to the concrete. Such as retarder, for reducing early hydration heat of cement; the water reducing agent reduces the unit water consumption and the cement amount; and (3) an expanding agent fills in the gaps of cement, enhances the self-healing capacity of concrete, reduces cracks and the like. The expanding agent adopts calcium sulfoaluminate, the recommended blending amount is 10%, and the specific blending amount is determined by test.
6) The mixing water dosage is not more than 170kg/m 3
7) The water-gel ratio of the mixture is not more than 0.45, the dosage of the cementing material is preferably 320-350 kg/m 3 The content of chloride ions is not more than 0.10% of the total amount of the cementing material, and the content of alkali is not more than 3.0kg/m 3
8) The specific mixing proportion should be combined with the above principle, and design determination is carried out according to comprehensive consideration of experiments.
a. The mixture has good workability, fluidity, cohesiveness, water retention and other properties, and slump of 160+/-20 mm.
b. The prepared mixture has retarding time and slump loss meeting the construction requirement, and the slump loss of 1 hour is less than 30mm.
c. The concrete pumping performance is improved by mixing high-quality fly ash and slag powder, the hydration heat is reduced, and the release speed of the hydration heat is delayed.
d. FST-6 polycarboxylic acid high-performance water reducer is selected, so that the water-cement ratio is reduced, the release speed of hydration heat is delayed, and the cracking resistance of the concrete is improved.
e. The mixing ratio is a mass concrete mixing ratio, and 60d strength is adopted as a concrete strength index.
f. And finally determining the mixing ratio of C40 and C40P8 according to the early production and trial-and-development experience of a laboratory.
Fifth, supply and transportation of concrete
1) The sand and stones in the storage bin of the concrete mixing station should be covered by sunshade.
2) The temperature of the cement entering the machine is not higher than 60 ℃.
3) Ice water can be used for mixing, and the temperature of the concrete outlet machine is reduced.
4) The weather forecast should be closely concerned, and concrete pouring construction is avoided in rainy days, particularly in stormy weather.
5) Before pouring and opening, testers and quality staff are all in place, so that the slump and the expansion degree of concrete of each truck are ensured to meet the site construction requirements; the technical data carried by technicians at the commercial mixing station reaches a construction site along with concrete produced by a first vehicle, and the technical data and site constructors monitor the workability of the concrete together to provide site technical service; and (3) visually inspecting the slump and the expansion degree of the concrete delivered from each vehicle by a tester, and testing the slump and the expansion degree when necessary, and strictly forbidding delivery of unqualified products.
6) The engineering adopts commercial concrete, and a concrete technical protocol is signed before concrete supply, wherein the content comprises the requirements of raw materials, the total alkali content of the concrete, the technical indexes (initial setting time, molding temperature, workability and the like) of the concrete, the requirements of concrete technical data, environmental protection requirements and the like. During the casting of large volumes of concrete, laboratory professionals will serve the residence.
7) The material should be transported away from the rush hour in the morning and evening.
8) The large-volume concrete transport vehicle should have certain sun protection measures.
9) In the transportation process, the performance of the mixture is not adjusted by adding water into the mixture; when the additive needs to be supplemented for adjustment, the stirring transport vehicle should stir rapidly, and the stirring time should not be less than 120s.
10 When slump loss or segregation is serious in the transportation process, pouring into a mould is not needed when the working performance of the concrete mixture cannot be recovered by taking measures.
11 Because the engineering concrete amount is large and the pouring time is long, the project department committee is responsible for the traffic guidance of the No. 1 gate, temporarily controls the north construction road, and timely dredges traffic if the transportation route of the concrete tank truck is congested. The operator list and the division of the concrete construction work should be clear before the casting (in order to cope with the emergency such as the extension of the concrete casting time, the work list is arranged according to 48 hours).
Pouring and vibrating of concrete
1) The engineering linear accelerator machine room is preferably constructed by adopting integral layered pouring. A layering thickness of 300mm and not more than
The length of the vibrating rod is 1.25 times, and the interlayer intermittent time is not longer than the initial setting time of the concrete. In the pouring process of each layer of concrete, the method of 'one gradient, thin layer pouring, timely vibrating and one-time top' is adopted, so that the continuous pouring of a thick bottom plate is ensured, the occurrence of construction cold joints is avoided, the radiating surface of the concrete is increased as much as possible, and the early-stage concrete hydration heat dissipation is facilitated.
2) The on-site scheduling management is reinforced when the concrete is poured, so that the poured concrete is covered by the upper layer concrete before initial setting, and no cold joint is generated.
3) In the pouring process, the performance of the concrete is not adjusted by adding water into the concrete. The concrete slump must be tested by each car, a tester is responsible for testing the concrete slump constructed on the day, constructors test the slump of each car, and is responsible for checking whether the slump of each car meets the technical requirements of commercial concrete tickets and making slump test records. The slump of the mixture is preferably controlled to be 120-160 mm, and the maximum slump cannot exceed 180mm. If the concrete cannot reach the construction conditions, immediately returning to the concrete mixing station.
4) The temperature of the concrete in the mould should be controlled between 5 ℃ and 30 ℃, and the concrete pouring should avoid the high temperature period when the conditions permit.
5) The vertical falling height of the concrete is not more than 2.0m, and when the conditions are not met, the chute or the string cylinder can be adopted for auxiliary construction.
6) The concrete surface is firstly scraped by a long scraping rule, rolled by an iron roller for several times before initial setting, and then ground and compacted by a wood trowel so as to close the water collecting crack.
7) In the pouring process, the conditions of the steel bars and the embedded parts are observed frequently, when deformation and displacement are found, the pouring is stopped immediately, and measures are taken immediately to finish the concrete well before the poured concrete is coagulated.
8) The concrete is vibrated by using a high-frequency vibrator, the distance between inserting points of the vibrator is 1.5 times the action radius of the vibrator, the concrete is required to be quickly inserted and slowly pulled out during vibration, and in the vibration process, a vibrating rod is slightly pulled up and down so as to uniformly vibrate up and down, and the vibrating rod is required to be inserted into the lower layer by about 50mm so as to eliminate a joint between the two layers. The vibrating time of each point is preferably 20-30S, but the concrete surface is not obviously sinking any more, no air bubble is generated on the surface, and even cement paste is spread on the concrete surface. And when vibrating, the steel bars, the templates, the embedded parts and the like are forbidden to be contacted. Preventing leakage and over-vibration.
2) And (3) after the concrete is poured, carrying out secondary vibration before the concrete approaches to initial setting for 3-4 hours, and then scraping with a scraping ruler according to elevation lines and lightly wiping and pressing.
3) The surface cement paste of the mass concrete is thick, and bleeding phenomenon and floating paste are serious and should be carefully treated. The concrete surface treatment achieves three-pressing three-leveling. Firstly compacting by using a clapping plate according to the elevation of the surface, and scraping by using a long scraping rule; secondly, rolling and leveling the steel plate by using an iron roller for several times before initial setting; and finally, polishing, compacting and leveling by using the wood crabs before final setting so as to close the water-collecting cracks of the concrete. The rolling marks should be mutually connected when the iron roller rolls, and the times are respectively long and short.
Seventh measure for controlling crack prevention on concrete surface
The surface cement paste of the pumped concrete is thicker after vibrating, and surface cracks are easy to cause.
Firstly, when the uppermost layer of concrete is vibrated, the vibration time is controlled, and the phenomenon that a thick floating slurry layer is generated on the surface layer is avoided; after pouring and tamping, the extra floating slurry layer must be scraped off by a 2m long aluminum alloy scraping rule in time, and the extra floating slurry layer is scraped and pressed by melon seed slices, and the concrete surface is scraped and beaten to be flat according to a preset elevation control point. The pit-containing part must be filled with concrete, when the concrete slurry is collected near the initial setting, the concrete surface is subjected to secondary trowelling, and the wood trowelling is completely and carefully smeared twice, so that the flatness of the concrete is ensured, the shrinkage dehydration slit on the initial surface is closed, and other people except concrete constructors cannot walk on the concrete surface which is not dry and hard at will during the concrete slurry collecting and setting construction.
(eighth) concrete test block retention
Each pouring, under supervision of supervision, a special person and a commodity concrete factory representative jointly manufacture a concrete compression-resistant test block and an anti-permeability test block according to standard requirements, and standard maintenance and on-site maintenance under the same conditions are carried out. According to requirements of the acceptance specification of construction quality of concrete structure engineering (GB 50204-2015) 7.4.1 and 7.4.2, requirements of the acceptance specification of construction quality of underground waterproof engineering (GB 50108-2008) are:
1) Sampling the concrete with the same mixing proportion of not more than 100m3 for each mixing of 100 plates;
2) When the concrete mixed by each working class with the same mixing ratio is less than 100 plates, sampling is not less than once;
3) When one-time continuous casting exceeds 1000m < 3 >, sampling concrete with the same mixing ratio every 200m < 3 > at least once;
4) The concrete with the same mixing proportion is sampled at least once for each floor;
5) The waterproof concrete impervious test pieces are continuously poured in the same mixing ratio, and one impervious test piece (6 impervious test pieces in one group) is reserved every 500m < 3 >, and the number of impervious test pieces is not less than 2.
6) At least one set of standard maintenance specimens should be left in each sample.
7) The special personnel of the resident clear project department of the test block is responsible for, the test block under the same conditions must be recorded in detail by the data room in terms of weather conditions and temperatures every day, and each group of test blocks are summarized and sent to the detection center two days in advance for test when the speed of the test block reaches 600 ℃/d.
Summary of steps (nine): the method mainly aims to realize construction of concrete projects of inner and outer walls and top plates around a machine room in construction of a large-volume ultra-thick medical room anti-radiation concrete structure, the concrete projects of the machine room are considered to be large-volume concrete, the thickness of wall plates is ultra-thick, the concrete projects belong to sub-projects with larger dangers exceeding a certain scale, and the construction organization and the quality control of the construction process and the safety of the whole load of concrete pouring are considered, and maintenance and temperature control after the pouring are particularly important.
6. Structural concrete maintenance construction
Curing of concrete
1) And after pouring, adopting a heat preservation and moisture preservation measure of covering a film and covering geotextile. The inner wall adopts the measure of spraying maintenance with a mould, the outer wall is covered with a film and covered with geotextile for maintenance after the mould is removed, the top plate is covered with a film and geotextile for maintenance, and mortar is used for painting the back ridge for water storage maintenance after the strength is reached.
2) The mass concrete should be maintained by heat preservation and moisture preservation. After the concrete is poured, covering or spray curing work is needed to be carried out immediately before initial setting. The duration of heat preservation and maintenance is not less than 14d. The temperature difference (without concrete shrinkage equivalent temperature) between the inner surface and the outer surface of the concrete casting body is not more than 25 ℃, the cooling rate of the concrete casting body is not more than 2.0 ℃/d, the alarm temperature is 1.5 ℃, the temperature difference between the surface of the concrete casting body and the atmosphere is not more than 20 ℃, and the alarm temperature is 18 ℃.
3) The bottom plate and the floor concrete are cured by adopting a method of covering the thin film and geotextile, sprinkling water and curing water. The insulation cover layer is removed gradually in layers, and when the maximum temperature difference between the surface temperature of the concrete and the environment is less than 20 ℃, the concrete can be completely removed. The two sides of the inner wall and the outer wall of the linear accelerator machine room are preferably sprayed and maintained by using templates, and the maintenance is not less than 14d by using an intelligent spraying system.
4) Adopts a heat preservation and moisture preservation maintenance method to effectively control the temperature difference change
After the concrete is finally set, a plastic film coating is adopted on the surface of the concrete, so that moisture on the surface of the concrete cannot be lost, and the upper cover geotextile is covered by heat insulation, the surface of the concrete is maintained by water storage, the wall is maintained by spraying with a mold, and the protection time of the large-volume concrete is not less than 14d. Ensuring that the difference between the center temperature and the surface temperature of the concrete is not more than 25 ℃. The spray pipe arrangement is shown in fig. 21;
5) Temperature control method for reducing temperature by adopting circulating condensate pipe
Circulating condensation water pipes are uniformly distributed in the walls and the plates of the machine room, and when the temperature difference between the inside and outside of the concrete exceeds a temperature control value, the temperature is controlled by timely passing through the condensation water, so that the temperature is prevented from rising too fast. Generally, the temperature is reduced in a temperature controllable range without adopting condensation circulating water.
Installing cooling water circulation cooling pipe networks between wall steel mesh sheets after binding of the machine room wall steel bars is completed and before installing the templates, and connecting the cooling water circulation cooling pipe networks by using DN40 galvanized steel pipes, wherein steel pipe risers are reliably fixed on wall steel mesh sheet additional ribs by using binding tapes; and binding the reinforcing steel meshes at the middle layer of the floor slab, and horizontally installing a cooling water circulation pipe network in the floor slab by using DN40 galvanized steel pipes. After the concrete curing period is finished, the cooling water circulation pipe network uses 1: and (5) performing grouting filling on the high-grade expansion cement mortar with the weight of 0.5. The water pipes are arranged at intervals of 1500 in the transverse and longitudinal directions and are arranged at the central position of the wallboard. The condenser water tube arrangement is shown in fig. 22 and 23.
(II) temperature control
1) The engineering temperature measurement adopts a JDC-2 portable electronic temperature measuring instrument to measure the temperature, and consists of a host machine and temperature measuring wires, wherein the host machine is a portable instrument and is provided with a power switch, an illumination switch, a socket and a liquid crystal display screen, the measured temperature value can be digitally displayed, the temperature measuring wires are embedded and are made of plugs, wires and temperature sensors, and each temperature measuring wire can measure one point of temperature. The temperature measuring wire is pre-buried before concrete pouring, and after the pouring is finished, the power switch of the host computer is pressed down when the temperature is measured, the plug of the temperature measuring wire is inserted into the socket of the host computer, and the display screen of the host computer can display the temperature of the corresponding temperature measuring point.
As shown in fig. 24;
2) The large-volume concrete pouring body is responsible for heat preservation and maintenance work by special personnel, and is subjected to test records, wherein the test items are temperature difference between the interior and exterior, cooling rate and environmental temperature. The temperature measurement time interval is 2h after 1-3 d, 4-7 d is 4h after concrete pouring, and 8h after the concrete pouring; and (5) measuring the mold entering temperature, wherein each shift should not be less than 2 times. The temperature measurement duration is from the time when the initial setting of the concrete pouring is finished to the time when the maximum temperature difference between the surface temperature of the concrete and the environment is measured to be less than 20 ℃, and the temperature is maintained after the removable covering, and is not less than 14d.
3) The monitoring points in the large-volume concrete casting body are arranged at the middle positions of a 3-surface 3000mm thick wall and 2 2500mm thick plates, and are 5 points in total and fixed in place by adopting steel bars.
4) When measuring the temperature, firstly, using a thermometer to test and record the ambient air temperature and the temperature of the concrete surface; then the temperature measuring instrument is used for testing according to the serial number sequence of the temperature measuring points, when the temperature measuring instrument is tested, the data is read after the display number of the temperature measuring instrument is stable,
5) The temperature measurement data record book is important test data, and is clear to fill in, and is properly stored and cannot be lost. During the temperature measurement work, temperature measurement recording personnel should adhere to posts, carefully operate, strengthen responsibility, carefully record, and ensure the accuracy and the effectiveness of data.
6) The temperature monitoring is recorded by constructors and testers in real time, the technical part is reported every day, statistics and data arrangement are made by the technical part, and the statistics and the supervision are reported. When the temperature measurement data is abnormal, after the problem of temperature measurement equipment is eliminated, a layer of geotextile should be additionally covered for controlling the temperature difference in an emergency way.
(III) step summary: the concrete curing and temperature control method mainly aims at realizing concrete curing and temperature control in construction of a large-volume ultra-thick medical room radiation-proof concrete structure, and because the machine room is a key radiation-proof machine room, the concrete engineering is large-volume concrete, curing and temperature control after concrete pouring is finished are particularly important, the defects that cracks and the like of the concrete are unnecessarily influenced on the using functions of the structure are prevented, and the forming quality of the concrete is improved.
Compared with the traditional concrete structure engineering, the construction method of the radiation-proof concrete structure of the room for medical treatment with the ultra-thick volume is provided, the construction method of the floor, the side wall and the roof of the concrete structure of the room for medical treatment with the ultra-thick volume for radiation-proof is provided, the related construction methods of the steel bar engineering, the formwork support engineering and the concrete engineering in the construction process are solved, and the comprehensive analysis and description are made from foundation excavation to process steel bar, formwork and concrete and then to whole structure concrete pouring maintenance construction.
Specifically, a foundation template construction method on an earthwork excavation surface in an ultra-deep foundation pit is provided, and brick molding bed specifications and masonry construction work amount are controlled according to foundations of different depths; for the super-thick raft, the outer wall and the top plate of the room area for the function, a reinforcing steel bar binding construction method and a erection method of a reinforcing steel bar engineering support frame body are provided, so that the stability and safety of the whole reinforcing steel bar plate surface are ensured; for the control of the structural construction joint, only one horizontal construction joint is reserved from the bottom plate to the top plate, and the rest ensures the integral molding; the template supporting system and the reinforcing of the wall body and the top plate are reasonably arranged in combination with the requirements of the demonstration situation of the dangerous engineering scheme, so that the stability and the safety of the template engineering are ensured; the construction scheme of integral construction is provided for concrete engineering, the aspects of large-volume concrete parameter proportion, casting construction sequence, casting process control, maintenance after casting, temperature control after casting and the like are controlled, the concrete forming quality is strictly controlled, and the radiation protection function of the functional house is ensured.
The invention is mainly based on the structural construction of the large-scale comprehensive medical building radiation protection function house, combines the internal environmental conditions of the construction site, starts from three main working procedures of a foundation, a reinforcing steel bar of a wall body top plate structure, a template and concrete, and details the specific requirements of each working procedure, the specific steps reaching the targets of each working procedure, each safety technical measure and each quality control standard meeting the use function. The invention can provide a set of completed construction method for the subsequent medical radiation-proof structural engineering and similar structural engineering construction, and the whole quality is safe and controlled.
The embodiments provided in the present application are not intended to limit the present application, and although the present application has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for some of the technical features thereof, but any modifications, equivalents, improvements, etc. within the spirit and principles of the present application are intended to be included in the protection scope of the present application.

Claims (10)

1. The construction method of the radiation-proof concrete structure of the medical house is characterized by comprising the following two parts:
A first part: and (3) foundation slab structure construction: the method comprises the steps of earth excavation, concrete cushion layer, waterproof and protective layer, baseboard reinforcement binding, embedded part, baseboard concrete pouring and baseboard concrete maintenance;
a second part: construction of a wall and roof structure: the method comprises the steps of binding wall steel bars, installing embedded parts in the wall, checking and accepting, installing wall templates, installing opposite-pull screws for reinforcing templates, erecting a support frame, installing a top plate template, binding plate steel bars, installing the embedded parts, checking and accepting, casting the wall, and maintaining the top plate concrete.
2. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the bottom plate reinforcing steel bar ligature and built-in fitting in the first part specifically do:
firstly, measuring construction;
(1) Performing plane control by using a total station and a theodolite according to a coordinate control point and an elevation reference point provided by a construction unit, and performing elevation guiding measurement by using the level meter;
(2) Setting a deep coordinate point in a construction area according to requirements according to coordinate control points provided by a construction unit, and building a site control network by using the deep coordinate point; a certain point in the plane control network is used as a measuring point (meeting the requirements of sight and convenience) for rechecking the site control network;
(3) The elevation is based on a level point provided by a construction unit, the value of the elevation is based on the latest provided value of the construction unit, and construction Gao Chengying is adjusted in time according to the latest data;
(4) The measuring instrument is selected from:
the measuring instrument used in the engineering mainly comprises a total station, a theodolite, a level gauge, a steel ruler and a tower ruler;
(5) Control of measurement accuracy and error range;
1) Angle measurement: adopting a back measurement method, wherein the error in the angle measurement is within 2' and the total error is within 2 mm;
2) Distance measurement: measuring with the identified steel tape;
3) The deviation between the axes of each layer is within 5mm, the vertical deviation of the layer height is within 5mm, and the vertical deviation of the total height is within 30 mm;
(II) excavating residual soil;
at the position 300mm away from the designed elevation of the substrate, a horizontal line is cut out, small wood piles are nailed, and then a temporary soil layer is dug away manually; after the substrate is repaired and leveled, quality inspection and acceptance are carried out; after digging to the designed elevation, timely notifying construction, investigation, design and supervision units of checking the grooves, forming groove checking records, and immediately constructing cushion layer concrete after the groove checking records are qualified;
thirdly, pile head treatment;
(1) Ejecting a cutting control line at a position 20mm above the pile top design elevation;
(2) Cutting a circle along the control line by using a portable cutting machine, wherein the cutting depth is preferably not contacted with the main rib;
(3) Stripping out the main reinforcement by using an impact drill and a pneumatic pick, then breaking pile core concrete by using the pneumatic pick or a hammer and a kettle, and finally chiseling and flattening the pile top by using the kettle;
(4) The pile head main rib of the filling pile should be corrected and the anchoring length is ensured; the main rib is strictly forbidden to be cut off, and no straight bending exists;
(5) Pile head waterproof reference method: the pile top and the periphery are coated with cement-based waterproof paint, the surface of a cushion layer around the pile is coated with a width not less than 200mm, the closing-in position of coiled materials around the pile is sealed by waterproof ointment, and a water-swelling water-stopping ring is arranged at the root of a pile main rib;
fourthly, constructing a foundation template;
brick die: autoclaved aerated concrete blocks 600mm by 200mm by 240mm, concrete solid brick blocks 240mm by 115mm by 53mm, and the two brickwork are mainly used for building super-high foundation bearing platforms, elevator shafts and retaining brick dies of water collecting wells; when the masonry height is 1200 < H and less than or equal to 2000, autoclaved aerated concrete blocks 600mm by 200mm by 240mm or solid bricks are adopted for masonry, and the thickness is 200 thick; when H is more than 2000, the parts below two meters are built by adopting concrete solid brick blocks 240mm 115mm 53mm, and the parts are built by adopting autoclaved aerated concrete blocks or solid bricks; when the wall length is greater than 2.5m, a 500mm brick column is additionally arranged, and when the wall height is greater than 4m, a 200mm concrete ring beam is additionally arranged;
Prefabricated fetal membrane of finished concrete: the specification is 3000mm multiplied by 600mm multiplied by 90mm, and the length can be customized according to the requirement; the method is mainly used for a conventional rectangular bearing platform soil-retaining side template or a ground beam side template, wherein the soil-retaining height H is less than or equal to 1500, and H is less than or equal to 1200, and a single-layer soil-retaining precast concrete bed-jig or solid brick is adopted for masonry;
(1) After the cushion layer construction is completed, popping up a bearing platform foundation positioning line;
(2) Installing a finished brick moulding bed along the marked line, and fixing the finished brick moulding bed through a reinforcing steel bar head;
(3) Reinforcing the seam of the fetal membrane through the templates and the battens to ensure the flatness and stability of the seam;
(4) Backfilling earthwork before removing the reinforced inner support, and binding iron wires on the steel bars to reinforce the periphery;
(5) The inner support can be dismantled and reinforced after the waterproof cushion layer is poured;
(6) And (3) reserving an outer wall construction joint: continuously pouring the wall body and the top plate at one time, and reserving a construction joint between the bottom plate and the outer wall at the position of 300mm in elevation;
binding reinforcing steel bars;
1) The process flow comprises the following steps:
binding beam steel bars, placing beam bottom cushion blocks, binding bottom plate steel bars, placing plate bottom cushion blocks, paying out wall column position lines on the steel bars, installing wall column dowel bars, reserving and embedding water and electricity heating, self-checking, mutual checking, handover checking, reporting, supervision and inspection acceptance;
2) Binding a reinforcing mesh; the intersection points of two rows of the reinforcing steel bars around the unidirectional stressed reinforcing steel bars are firmly tied at each point, the intersection points of the middle part can be tied in an intersecting and staggered manner, and the reinforcing steel bar net of the bidirectional main reinforcing steel bar is firmly tied at all reinforcing steel bar intersection points;
3) The bottom plate steel bars adopt double-layer steel bar meshes, and a steel bar split heads, steel bar supports or angle steel supports are arranged between the upper layer steel bar meshes and the lower layer steel bar meshes so as to ensure that the positions of the steel bars are correct; the hooks of the lower layer of steel bars face upwards, and the hooks of the upper layer of steel bars face downwards;
4) The hidden column is connected with the inserted bar for the foundation, and the bending section at the tail end of the inserted bar is firmly fixed with the steel bar of the bottom plate;
5) The reinforcing steel bars of the basement bottom plate extend to the outer edge of the bottom plate;
6) The plate construction is noted in the figures;
7) The long-direction reinforcing steel bars of the bottom plate of the plate are arranged above the short-direction reinforcing steel bars; the long negative ribs of the plate at the support seat are arranged below the short negative ribs, and the length of the plate bottom ribs extending into the beam support seat is more than or equal to 10d and exceeds the center line of the beam;
8) When the bottom of the plate is level with the bottom of the beam, the lower rib of the plate is bent near the beam edge according to the gradient of 1:6 and then stretches into the beam and is arranged above the longitudinal rib at the lower part of the beam;
9) The holes on the plate are reserved, the holes with the hole size of more than 300mm are only shown in a general structural plan, all holes are reserved according to the cooperation of each professional drawing in construction, when the hole size is less than or equal to 300mm, the reinforcing steel bars are not additionally added to the hole edges, and the reinforcing steel bars in the plate are bypassed by the hole edges and cannot be cut off; when the size of the hole is more than 300mm, except for the person noted in the figure;
10 The slab reinforcement is not cut off at the equipment pipe well where the concrete slab is required to be plugged, and after the equipment pipe is installed, the compensation shrinkage concrete casting with the strength grade not lower than that of the slab concrete on the same floor is adopted;
11 When the pipeline is embedded in the plate, the pipeline is placed between the plate bottom and the plate top steel bars, and the outer diameter of the pipeline is not more than 1/3 of the plate thickness; when the pipelines are arranged in parallel, the horizontal clear distance between the pipelines is not less than 3d (d is the pipe diameter); when the pipelines are crossed, the thickness of the concrete protective layer of the pipeline at the crossing part should not be less than 25mm;
12 Exposed cast-in-situ reinforced concrete parapet, hanging plate, breast board, and Seriola, when the horizontal straight line length exceeds 12m, the induced seam should be arranged, the interval between the induced seams is not more than 12m, and the seam width is 20mm;
13 Double-layer bidirectional additional reinforcing steel bar meshes are additionally arranged at external corners of walls or beams of the roof abnormal plates of each floor, and when the cross floor is double-layer bidirectional through length reinforcing steel bars, if the spacing between the reinforcing steel bars at the plate corners does not meet the requirements, C8 short bars can be additionally added to meet the spacing requirements; the plate surface of the external corner of the roof cornice cantilever plate is additionally provided with a radial rib;
14 A construction diagram of related structures of the unequal-height plate reinforcement structure;
15 Except for the noted person, the length of the negative rib is calculated from the middle support in the middle support, and the edge support is calculated from the outer side of the beam;
16 Foundation mat reinforcement bracket arrangement principle):
the thickness of the bottom plate is 700mm (C20@150 double-layer bidirectional) except the reference, and the thickness of the bottom plate of a basement with the height of only one layer is 500mm (C18@150 double-layer bidirectional) except the reference;
(a) The steel bar support columns are arranged in a groined manner, a C20 steel bar pull rod is horizontally added to the middle of each column at the position of a local pit (such as an elevator foundation pit, a water collecting well and the like), the bottom plate beams with the thicknesses of 700mm and 500mm are all C22 steel bars, and the columns are respectively C20 steel bars and C16 steel bars;
(b) As shown in the following figure, the inclined strut C16 steel bars are not oriented in the same direction and are arranged at certain intervals left and right;
17 Basic raft steel bar bracket arrangement principle):
(a) The steel bar support columns are arranged in a groined manner, and a C20 steel bar pull rod is horizontally added to the middle of the columns at the position of a local pit (the position of an elevator foundation pit, a water collecting well and the like);
(b) As shown in the following figures, the diagonal braces are not oriented in the same direction and are arranged at left and right intervals;
(c) The figure is applicable to raft h=2200 mm (20@150) rebar scaffold arrangement;
18 A large-area foundation pile cap reinforcement bracket arrangement principle;
(a) The steel bar support upright posts are arranged in a groined manner;
(b) As shown in the following figures, the diagonal braces are not oriented in the same direction and are arranged at left and right intervals;
(c) The drawing is suitable for the arrangement of the reinforcing steel bar bracket with a larger area of bearing platform h=2100 mm (25@100);
(d) And when the height of the bearing platform is greater than 2m, a C12@200mm reinforcing steel bar net is arranged in the middle of the height of the bearing platform.
3. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the bottom plate concrete placement in the first part specifically is:
firstly, construction requirements;
1) Basement bottom plate adopts inclined plane layering to pour, follows "inclined plane layering, and a slope (pumping concrete is 1: 6-1: 10 The thin layer covering and progressive principle, wherein the thickness of each layer is 500-600 mm, the layers are pushed from one side of the raft foundation to the other side, and then thin layers are poured and smashed in sequence and are topped once; gradually moving upwards from the lower end of the pouring layer during construction so as to ensure the quality of concrete;
2) All pump pipes are supported in place, and each row of conveying pipes are fixed in point and are in charge of each other during pouring;
3) Directly distributing materials on the surface of the bottom plate epithelial steel bar by using a pump pipe or a hose connected in front of the pump pipe, and on the premise of ensuring that the concrete does not generate cold joints, spreading the concrete in a fan shape by using the hose to move left and right, so that the spreading area of the concrete in the mold is increased as much as possible to increase heat dissipation and heat exchange;
4) Covering the poured concrete for a period of time not exceeding the initial setting time of the concrete so as to avoid cold joints;
5) According to the range of concrete flowing speed of the large-volume foundation slab, the construction of pumping concrete in the elevator shaft and the water collecting pit is needed to be carried out in advance, and the concrete is compacted by vibrating; pouring the concrete of the elevator shaft and the water collecting pit to be level with the large bottom plate, and tightly connecting the concrete part of the elevator shaft and the water collecting pit with the concrete part of the foundation bottom plate;
6) The concrete in the elevator shaft and the water collecting pit adopts an intermittent pouring method, the templates are made into a whole and erected in advance, the concrete is poured to be flat with the templates, when the mobility of the pit bottom concrete is not large and the pit wall concrete pressure can be born, the pit wall concrete is poured again, and the quality of the contact position of the bottom and the wall is ensured; the intermittent time is about 2 hours;
7) The pit bottom pouring sequence is poured and pushed from one end to the other end in the length direction, or poured from two ends to the middle; forming a ring loop on the pit wall for layered pouring; when the concrete on the side wall of the water pit is poured, a symmetrical pouring method is adopted to ensure that the stress of the side wall template is uniform;
8) After the concrete is poured and is coated for the first time, covering and curing are started, and a curing method of heat preservation and moisture preservation is adopted;
9) The covering method comprises the following steps: the bottom plate adopts a method of 'single-film single-layer geotextile', namely a layer of heat-preservation gunny bag is covered on a layer of plastic film; the side wall adopts a method of 'single-film double-layer geotextile', namely, a layer of plastic film is covered with two layers of heat-insulating geotextile; the heat-insulating geotextile is covered outside the side mould, so that the moisture and hydration heat on the surface of the concrete are not lost, the internal and external temperature gradients of the concrete can be reduced, the internal and external temperature differences of the mass concrete are ensured, and the strength growth and the crack control of the concrete are facilitated; watering and curing are not needed during covering and heat preservation, the surface temperature is prevented from dropping too fast, meanwhile, the covering tightness of plastic cloth is guaranteed, the lap joint is not less than 200mm, bricks and square timber are pressed, and the side wall is fixed by element nails; the maintenance starting time is when the surface strength can be on the person; the plastic cloth cannot be uncovered at will to perform other operations on the concrete surface during maintenance;
10 During curing and temperature measurement, the highest temperature, the surface temperature and the atmospheric temperature of the concrete at each temperature control point are provided in time, so that the on-site heat preservation and curing are guided, the heat dissipation of the heat preservation layer is reduced at the midday and the afternoon to shorten the heat preservation and curing time, and the heat preservation and curing time is covered again at night;
11 Heat preservation time: according to the temperature measurement record, when the central temperature of the concrete starts to drop and approaches to the surface temperature, and the temperature difference between the central temperature of the concrete and the atmospheric temperature is less than 25 ℃, the heat preservation is started to stop; removing the plastic film and the heat-insulating gunny bag layer by layer, and keeping a certain time interval according to the measured temperature after each layer is removed so as to avoid generating larger temperature gradient;
12 According to the actual measurement data, firstly removing the upper heat preservation layer, then completely removing the heat preservation layer, and carrying out watering maintenance for at least 14 days;
13 The engineering mass concrete structure is of a rectangular structure, temperature measuring points are arranged on the most unfavorable section of the whole basic temperature, rectangular diagonal positions are arranged on the long sides of the rectangle, 4 points are symmetrically arranged on the half sides of each most unfavorable axis, one temperature measuring point is arranged on the center of a plane for the mass structure with smaller size, and three temperature measuring points are arranged along the thickness direction of the structure.
4. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: binding wall steel bars in the second part specifically comprises:
1) The process flow comprises the following steps:
a, treating a root construction joint, overlapping and welding vertical steel bars, checking a welded joint, binding column stirrups, binding non-waterproof wall steel bars, placing cement stay bars, reserving and embedding water and electricity heating, self-checking, mutually checking, cross-checking, reporting, managing and checking;
b, root construction joint treatment, vertical steel bar overlap joint and welding, inspection of welded joints, binding of column stirrups, binding of waterproof wall steel bars, water heating reserved pre-embedding, installation of protective layer cushion blocks, self-checking, mutual checking, handover checking, supervision and inspection acceptance;
2) The hidden column stirrups are perpendicular to the stressed bars, the overlapping positions of the hooks are staggered and bound along the direction of the stressed bars, the crossing points of the corners of the stirrups and the longitudinal steel bars are firmly bound, the binding buckles are splayed when the stirrups are bound, the stirrups are flat and straight, the opposite angles of the openings are staggered and spirally bound, the specification interval is according to the drawing, and the tail parts of the binding wires face to the column center of the wall;
3) When the section of the wall column is changed, the bending part of the reinforcing steel bar must be within the height of the beam column wall node;
4) The beam connecting steel bars are arranged on the inner sides of the longitudinal steel bars of the wall columns;
5) Binding a reinforcing steel bar net of the wall with a foundation, wherein hooks of the reinforcing steel bars face the inner side of the wall column;
6) The shear wall body is manufactured by structures such as horizontal steel bars, vertical steel bars, edge members, connecting beams, hole reinforcements and the like;
7) The shear wall body is double-layer bidirectional reinforcement, the reinforcement is vertically distributed on the inner side, and the reinforcement is horizontally distributed on the outer side;
8) The lacing wires are arranged in plum blossom mode;
9) The horizontal distribution steel bars of the wall limbs in the height range of the shear wall connecting beam are used as waist bars of the connecting beam in the connection Liang Nala;
10 Manufacturing a shear wall constraint edge component structure;
11 Hole on wall must be reserved, and back chisel is not needed; for the discontinuous small hole, when the length of each side of the discontinuous small hole is less than 800mm, the discontinuous small hole is operated according to the sign and reinforced;
12 The allowable deviation of the templates and the walls of the shear wall must be strictly executed according to the relevant regulations of construction acceptance regulations, concrete must be poured and tamped in layers, the pouring heights of the first layer and each later layer must not be more than 500mm and 1000mm respectively, and the interface surfaces must be cleaned, so that good concrete combination is ensured;
13 The specification, the size, the spacing, the row spacing, the lap joint length, the anchoring length, the thickness of the protective layer and the like of the wall steel bars meet the design and specification requirements;
14 The binding of the reinforcing steel bars is firm, all the crossing points should be bound, and the binding buckle should face to the inner side; the positions of the binding overlap joints of the reinforcing steel bars are staggered, the staggered distance meets the requirement, and three binding buckles and three horizontal ribs pass through within the binding overlap range of the vertical ribs of the wall body;
15 The wall body drag hook is bound on the intersection point of the horizontal steel bars and the vertical steel bars, the overlapped part of the hooks is bound in a staggered mode along the direction of the stressed steel bars, and the bound drag hook is clamped by a tool type clamp and then bent, so that the arrangement distance of the steel bars is kept unchanged;
16 A top mold rod for fixing the gate, a steel bar for fixing the box and a grounding wire are tightly forbidden to be welded on the stressed steel bar;
17 Wall measure reinforcing steel bar): in order to ensure that double-layer steel bars of the wall are horizontal and vertical, the distance is uniform and correct, and vertical ladder bars are used for limiting; in order to ensure the thickness of the wall, a short steel bar internal support is added at the opposite-pull screw rod, the two ends of the short steel bar are smooth, and antirust paint is brushed; after the wall rib is bound, correcting the position of a main rib of a door and window opening node to ensure the thickness of the protective layer; the number of the binding threads of the wall body steel bar lap joint is not less than 3, and the binding threads are inwards.
5. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the installation wall body template in the second part specifically is:
1) Positioning and lofting the wall profile before installing the wall template, and alternately installing the template and the batten at one time until the whole wall is installed; before the template is installed, the positions of the opposite-pulling screws are calculated, holes are formed according to the specified intervals, and for the inner wall, the template can be installed first and then the screws are placed for reinforcement; for the outer wall, a counter-pulling water stop screw rod is arranged before the formwork is installed and erected, and then the whole reinforcement is carried out;
2) When the loose-splice shaping template is adopted for supporting the template, the template should be carried out from bottom to top, and the upper layer of the template can be installed after the lower layer of the template is completely fastened; when the lower layer cannot be independently provided with the supporting piece, temporary fixing measures should be taken;
3) When the prefabricated large wall templates are adopted for formwork erection, 2 templates are strictly forbidden to be lifted at the same time, and are positioned, corrected and connected at the same time, and the fixed templates can be unhooked;
4) Before installing the inner wall mould of the elevator shaft, a layer of scaffold board must be firmly fully paved at the position 200mm below the board bottom;
5) Before the split bolts are installed on the template, the plate surface is inclined backwards by a certain angle;
6) When the length of the steel ridge needs to be lengthened, the same number of steel ridges with the same specification or not less than the original specification are added at the joint, and the lap joint length of the steel ridge is not less than 15% -20% of the width or the height of the wall template;
7) The U-shaped cards are required to be installed in a positive and negative alternate mode during splicing, and the distance is not more than 300mm; the U-shaped clamp at the butt joint seam of the 2 templates is fully assembled;
8) The split bolts are vertical to the wall templates, the tightness is consistent, and the wall thickness is correct;
9) The internal and external supports of the wall form board must be firm and reliable, and the integral stability of the form board should be ensured; when the outside of the wall template cannot be provided with a support, the inside of the wall template is provided with a support capable of bearing tension and compression; when the wall templates are integrated with the support, measures should be taken to prevent adjacent templates from deforming when concrete is poured.
6. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the erection support frame in the second part specifically is:
(1) The construction process flow;
paying off and checking, setting up a full framing, paving a main steel pipe keel, paving a wood keel and a wood veneer surface layer, performing self-checking and checking;
(2) Constructing a vertical rod and a horizontal rod;
1) Lap joint requirements: the upright posts at all parts of the project are connected by connecting sleeves, and overlap joint is forbidden;
2) The upright rod connecting sleeve can be a cast steel sleeve or a seamless steel tube sleeve; the length of the vertical rod connecting sleeve in the form of cast steel sleeve is not smaller than 90mm, and the insertable length is not smaller than 75mm; the length of the vertical rod connecting sleeve in the form of a seamless steel pipe sleeve is not smaller than 160mm, and the insertable length is not smaller than 110mm; the gap between the inner diameter of the sleeve and the outer diameter of the upright steel pipe is not more than 2mm;
3) The vertical rod and the vertical rod connecting sleeve are provided with anti-extraction pin holes for fixing the vertical rod connecting piece, the aperture of the pin holes is not more than 14mm, and the allowable size deviation is +/-0.lmm; the diameter of the upright connector is preferably 12mm, and the allowable dimensional deviation is +/-0.lmm;
4) Setting a sweeping rod at the position of the bottom of the vertical rod which is not higher than 500mm away from the ground according to a procedure of longitudinal and transverse directions along the longitudinal and transverse directions;
5) The horizontal rods in the longitudinal and transverse directions of each step are connected and pulled through the disc buckle nodes;
6) Before the vertical rod and the horizontal rod are erected, measuring and paying-off of beam slab rod pieces are carried out according to the erection requirement, the vertical rod point position is checked after paying-off is finished, and rod piece erection can be carried out according with the requirement;
(3) An adjustable base and a jacking;
1) The screw rods of the adjustable base and the adjustable bracket are preferably trapezoidal teeth, the A-shaped upright rod is preferably provided with a 48 screw rod and an adjusting handle, the outer diameter of the screw rod is not less than 46mm, the B-shaped upright rod is preferably provided with a 38 screw rod and an adjusting handle, and the outer diameter of the screw rod is not less than 36mm;
2) The bottom plate of the adjustable base and the adjustable bracket supporting plate are preferably made of Q235 steel plates, the thickness of the adjustable base and the adjustable bracket supporting plate is not smaller than 5mm, the allowable dimensional deviation is 2mm, and the length and the width of the steel plates of the bearing surface are not smaller than 150mm; the steel plate of the bearing surface and the screw rod are subjected to ring welding, and stiffening sheets or stiffening arches are arranged; the adjustable bracket supporting plate is provided with an opening baffle, and the height of the baffle is not less than 40mm;
3) The screw rod of the adjustable base and the adjustable bracket is not smaller than 5 buckles, the thickness of the nut is not smaller than 30mm, the cantilever length of the adjustable bracket of the template bracket extending out of the top level rod or the double-groove steel joist is strictly forbidden to be more than 650mm, the exposed length of the screw rod is strictly forbidden to be more than 300mm, and the length of the adjustable bracket inserted into the vertical rod or the double-groove steel joist is not smaller than 150mm;
4) The exposed length of the adjusting screw rod of the adjustable base of the plate bracket is not more than 300mm, and the height of the bottom horizontal rod serving as the floor sweeping rod from the ground is not more than 550mm;
(4) Diagonal rod and scissors stay arrangement;
1) When the template support in the high formwork supporting area is erected, the vertical diagonal rods are required to be arranged according to the standard requirement, the step distance of the horizontal rods is not more than 1.5m, and the steel pipe fastener scissor supports are required to be arranged at intervals of 4-6 standard step distances along the height; when the periphery is provided with a structure, a reliable drawknot is formed with the periphery structure;
2) When the template support is set up into an independent tower-shaped support without lateral drawknots, each step of distance on each side face of the support body is provided with a vertical diagonal rod; when the torsion prevention requirement exists, a horizontal layer diagonal rod or a steel pipe horizontal scissor brace is additionally arranged on the top layer at intervals of 3-4 steps;
3) The steel pipe scissor support is fixed on a vertical rod or a horizontal rod which is intersected with the steel pipe scissor support by adopting a rotary fastener, and the distance from the center of the rotary fastener to a main node is not more than 150mm; the slenderness ratio of the scissors is not more than 200;
4) When the knife support is connected, the knife support is in lap joint, the lap joint length is not less than 1000mm, not less than 2 rotary fasteners are arranged, and the fasteners at the two ends are fixed at the position not less than 100mm away from the rod end;
5) The knife rest is synchronously erected along with the vertical rod and the horizontal rod in the longitudinal and transverse directions, and cannot be installed in a lagging way;
6) The horizontal scissor support needs to simultaneously tie the column frame body and the beam area frame body;
7) The project frame body adopts standard type support frame bodies, and the design value of the vertical rod axial force is within 40 KN; the specific arrangement requirements of the vertical diagonal rods are as follows:
the vertical shaft axial force design value and the scaffold setting height are the maximum value in the unified independent frame;
each span represents that the vertical diagonal rod is erected along the longitudinal direction and the transverse direction; the first span is the vertical diagonal rods are erected at intervals of 1 span along the longitudinal direction; interval 2 spans, 3 spans and so on;
(5) The spacing does not conform to the modulus adjustment;
1) Setting an adjusting span at the position of the plate when the modulus is not matched;
2) The adjusting span is arranged at the position with smaller bearing load under the plate, and is integrally formed by pulling the steel pipe with the common fastener at each step;
3) The horizontal rod extends to two ends and is at least buckled with the vertical rods of 2 shaping brackets;
4) Gaps with different distances exist in the erecting process of the Liang Banjia body, steel pipes are needed to be connected in a drawknot mode every span, and the connecting fasteners are connected to the vertical rods in a drawknot mode.
7. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the roof template in the second part is installed, specifically:
1) The template can be sealed after the steel bar is concealed and accepted;
2) Template mounting sequence: a vertical structural die, a beam die and a platform die; after each single template is finished, the single template can be transferred to the next procedure after self-checking and technical rechecking; checking the upper port elevation when checking the vertical structure mould;
3) Carefully checking the quality of the entering template, wherein the wood template is required to adopt a perfect clamping plate; the various templates are required to be solid, smooth and intact; checking the size of the fixed processing template;
4) Ejecting all the beams, columns and wallboard edges according to the turnover diagram; the vertical template must be strictly processed according to elastic lines; the lower parts of the wallboards and the columns are limited by welding the reinforcing bars with the wall bars and the column bars;
5) Checking the positions, the sizes, the specifications, the number and the fixing conditions of the embedded parts and the reserved holes before installing the template; the method is coordinated with an installation unit, and the installation of the pipeline in the wall is guaranteed before the template is sealed;
6) Before the column and the wallboard mould are sealed, garbage and sundries in the mould are cleaned, and the floating ash is cleaned by compressed air;
8) The elastic wire vertical bent is required to be horizontal and vertical; the perpendicularity and the interval of the upright posts, the arrangement of the scissors supports and the arrangement of the joints when the upright posts are lengthened are in accordance with the scheme requirements;
9) The net span of the short side of the floor is more than or equal to 4m, and the arch starting value of the center of the floor is 2/1000 net span; the cantilever plate has a cantilever length of more than or equal to 1.5m, and the cantilever section end arch value is 4/1000 of the cantilever length; the span of the beam is more than or equal to 4m, and the span arch value of the beam is 1/1000-3/1000 net span; the beam span is more than or equal to 9m, and the arch starting value in the beam span is 1/500 net span;
10 The beam and column node templates have clear relationship and firm fixation; the joint part is inlaid by a 50mm thick wood die, and the thin plate is forbidden;
11 Flatness control and slurry leakage prevention operation points:
the side dies of the beam and the wallboard are arranged in staggered joint, the templates are tightly spliced, and a box sealing paper tape is stuck at the embedded joint;
before installing the column and the wallboard bottom templates, cleaning the root parts of the column and the wallboard bottom templates, leveling the vertical templates by using mortar to ensure that the elevation of the vertical templates is consistent and preventing slurry leakage from the root parts;
the template at the construction joint part of the stair is provided with a cleaning opening, so that quality common problems such as slag inclusion and the like are avoided;
12 The steel pipe fastener transverse and vertical enclosing purlins and the opposite-pulling screw rods are strictly arranged according to the requirements, the double-spliced transverse enclosing purlins are arranged in a unified length mode, joints are staggered, and hook head bolts are arranged according to the requirements of a turnover diagram so as to effectively control the section size of a component and strengthen the overall rigidity of a beam and a wallboard;
13 The long twine is pulled and fixed firmly with the bent frame when the side die is fixed;
14 The template is installed to be positioned correctly, supported firmly and the plate surface is flat; the special person takes charge of checking and rechecking.
8. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the binding plate reinforcing steel bars in the second part are specifically as follows:
1) The process flow comprises the following steps: installing beam steel bars, sinking beams, correcting and arranging bottom surface and side surface steel bar protection layer cushion blocks, mounting plate steel bars, mounting plate steel bar protection layer cushion blocks, pre-burying and mounting plate surface layer steel bars (upper layer steel bars if double-layer steel bars are adopted), supporting, mounting split heads, self-checking, mutual checking, special checking, reporting, supervision and acceptance;
2) The protective layers of the steel bars at the bottom and the side of the beam adopt mortar/concrete cushion blocks, the steel bars of the beam adopt overhead binding, the beam is submerged by other equipment such as a hoist, and the like,
3) Bending the beam main reinforcing steel bars when the length of the horizontal section of the beam main reinforcing steel bars extending into the wall column is smaller than the anchoring length so that the beam main reinforcing steel bars meet the anchoring length; when the length of the horizontal section of the secondary beam extending into the main beam is less than 0.4La, the joint of the primary beam and the secondary beam should be respectively bent downwards and upwards; if the support meets the anchoring length of the main steel bar of the beam, the steel bar at the bottom of the beam extends at least 5d beyond the axis; when two rows of beam main steel bars are arranged, a cushion block (the short steel bars with the thickness phi of 25) with the thickness not less than 25mm is arranged between the two rows of steel bars; the lap joint binding joints should be provided with three-point binding, and any joints must be staggered; binding each point of the crossing point of the stirrup and the main bar, and folding the end part of the binding wire into the framework;
4) The intersection points of two rows of steel bars at the periphery of the unidirectional plate are all bound, the intersection points of the middle part can be indirectly bound, and the intersection points of the bidirectional stressed bars are all bound;
5) The plate hogging moment bar is positioned by adopting an I-shaped split heads, and the split heads are arranged at the end parts of the hogging moment bars;
6) The steel bar connection mode comprises binding connection, mechanical connection and welding, and the engineering frame column longitudinal bars are preferably mechanically connected; the beam longitudinal reinforcement joint is suitable for avoiding a beam end stirrup encryption area, and mechanical connection cannot be adopted when avoiding; other parts can be bound; the diameter d of the steel bar is more than or equal to 22, and the longitudinal bars of the conversion beam are mechanically connected;
7) Arranging a reinforcing steel bar support frame;
the thickness B=1600 mm of the top plate of the machine room, and the plate reinforcement C25@150mm is double-layer bidirectional; and tie bars which are arranged in a bidirectional quincuncial manner and C8@600 are arranged between the two steel bar meshes in the wall body and the top plate of all the machine rooms.
9. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the concrete of the cast wall and the roof in the second part is specifically:
firstly, constructing mass concrete;
(1) Pouring concrete;
1) The integral and impervious performance requirements of the large-volume concrete foundation slab are high, concrete is poured continuously, and no construction joint is left;
2) Adopting a layered pouring method, wherein the layered pouring can be performed by adopting inclined plane layering and block layering methods;
under the condition of ensuring continuous casting of each layer, the intermittent time between the layers is shortened as much as possible, and after the casting of the lower layer concrete is finished, the pipe is firstly disassembled and returned to the initial casting position, and then the upper layer concrete is cast, so that the continuity of the whole concrete casting process is ensured; the casting thickness of each layer of the large-area concrete is controlled to be about 500 mm;
3) Marking lines of the vertical indicating rod before casting to mark casting thickness of each layer; during pouring, a pump pipe distributing machine is adopted, and each pump is responsible for one area; the total time of concrete transportation, pouring and intermittence does not exceed the initial setting time of the concrete; the construction sequence is reasonably arranged in construction, the concrete is controlled to uniformly rise in the pouring process, the layered pouring can fully radiate hydration heat of the lower layer concrete in the initial setting time, the heat storage capacity of the concrete can be reduced, the accumulation of the hydration heat is prevented, and therefore the temperature stress is reduced;
4) The free falling height is not more than 2m when the concrete is poured, and if the free falling height is more than 2m, a method of lengthening a hose and stringing barrels is adopted; during the pumping process, enough concrete should be in the hopper to avoid the blockage caused by air suction;
(2) Vibrating the concrete;
1) After the concrete is put into a mould, the concrete is flattened and vibrated in place by an inserted vibrating rod;
2) In the pouring process, concrete vibration is an important link, the concrete is strictly operated according to an operation rule, quick insertion and slow pulling are realized, the quick insertion is used for preventing bubbles in lower-layer concrete from being discharged after the compaction of upper-layer concrete, and the slow pulling is used for enabling the concrete to fill up a cavity caused by a rod; in the vibrating process, the vibrating rod slightly moves up and down to compact the concrete, the insertion points are uniform, the distance between the insertion points is controlled to be 50cm, and the distance from the template is 20cm; the single row form is adopted, and the concrete is not required to be mixed with the staggered type so as to avoid vibration leakage, the vibration point time is generally controlled between 20 and 30 seconds until the surface of the concrete is flooded, no air bubbles appear, and the concrete is not sunk;
3) The vibrator can not collide with the reinforcing steel bars, the templates and the embedded parts during vibration;
4) The intermittent time is accurately controlled in the pouring process, the upper layer concrete is poured before the lower layer concrete is initially set, and when the upper layer concrete is vibrated, a vibrating rod is inserted 5cm downwards, so that the upper layer concrete and the lower layer concrete are better combined;
Secondly, concrete construction measures are taken;
(1) Technical measures;
in order to ensure the construction quality of concrete engineering, the following measures are adopted:
1) In order to ensure that the concrete is not cracked, a water reducing agent is added into the concrete;
2) In autumn and winter, the average temperature of the Hangzhou is 17-25.3 ℃, and the concrete pouring should avoid weather; controlling the surface temperature of the concrete to be not more than 30 ℃;
3) And (3) treating the concrete surface of the construction joint: roughening the loose concrete part to expose the hard part, and cleaning with water;
4) In the concrete pouring construction, the protection of reserved and embedded parts is paid attention to;
5) Professional training is carried out on management staff before construction, technical communication is carried out step by step, and construction control key points of a linear accelerator machine room are familiar;
(2) Concrete temperature control and shrinkage crack pre-control measures;
1) Controlling the temperature of the concrete;
in order to effectively control the occurrence and development of harmful cracks, measures which are comprehensively considered in the aspects of controlling hydration temperature rise, delaying temperature reduction rate, reducing shrinkage of concrete, improving ultimate tensile strength of concrete, improving constraint conditions, designing structures and the like of the concrete are necessary;
2) Reducing the temperature of concrete entering a mould;
The retarder is properly used in the concrete stirring engineering to prolong the initial setting time of the concrete, the initial setting time is adjusted to 8-10 hours, and the hydration heat peak is delayed, so that the internal temperature of the concrete is reduced, and the molding temperature of the concrete is controlled;
3) Cooling measures in the concrete pouring process;
the length of the concrete conveying pipe is reduced as much as possible, the elbow is reduced, so that the loss in the concrete slump conveying pipe and the concrete molding temperature are reduced, the concrete is poured in a slope layering and step-type propelling mode, the thickness of each layer of concrete pouring is reduced under the condition that cold seams are not formed, and the thickness of each layer is not more than 300mm, so that hydration heat is sufficiently dissipated in the pouring process, and the later hydration heat is reduced;
(3) Other pre-control measures;
a. when the concrete is poured, the vibration is compact, so that the shrinkage is reduced, and the cracking strength of the concrete is improved; and the panel is smeared and pressed, and the secondary smeared and pressed can be carried out after the initial setting and before the final setting of the concrete so as to improve the tensile strength of the concrete and reduce the shrinkage;
b. the surface of the concrete is subjected to heat accumulation and moisture preservation maintenance, so that the moisture in the concrete can be effectively sealed and evaporated, the concrete can be maintained under a humid condition, the generation of shrinkage cracks is controlled, and a gunny bag is covered for heat preservation, so that the surface heat dissipation is reduced;
c. The moisture preservation maintenance can smoothly carry out cement hydration, improve the ultimate tensile strength of concrete, reduce temperature stress and shrinkage cracks on the surface of the concrete, and finally ensure that the temperature gradient of the internal and external concrete is within the allowable range of design and specification;
d. when gunny bags are hung on the outer side surface and the inner side surface of the wall die, the gunny bags are covered in a strip shape by using iron wires, a cover Yan Tieshi is fixed on the enclosing purlin, and the gunny bags are plugged in the wood baffle area grid; intelligent spraying, heat preservation and moisture preservation are carried out for at least 14 days during maintenance;
e. during the heat preservation period, especially when the top plate is in heat preservation, the linear accelerator chamber entrance door is closed, so that heat dissipation can be effectively prevented;
f. during the heat preservation period, the fire prevention safety work of the adjacent areas is required to be done, and the operation of smoke and nearby fire is strictly forbidden;
g. the removal time of the heat preservation layer refers to the analysis result of the temperature measurement data of the mass concrete engineering; the concrete method is that the insulation materials are removed in layers, and the construction personnel is forbidden to remove the form in advance without permission;
thirdly, constructing a large concrete in a machine room;
pouring concrete of a bottom plate, a wall body and a top plate in layers according to the height of each 300mm, pouring 1 day pump and 1 ground pump into 3 direct-adding machine rooms at the same time, and dividing the pouring range of each pumping mechanical equipment according to the arm length of the day pump and the concrete pouring experience of the bottom plate; taking 3 pouring points of wall concrete, and rotationally pouring pumping mechanical equipment in a range; taking a pouring point every 4 meters of roof concrete, and circularly pouring 3 pumping mechanical equipment from two sides to the middle in the respective range;
Casting a beam slab column in a common area: firstly pouring and constructing a C50 structural column and a shear wall of a main building area, and then pouring a shear wall column of an inner and outer wall connecting area, wherein the connecting parts with different marks are required to be synchronously poured on two sides; the basement outer wall is poured in layers, the layering thickness is not more than 50 cm, and the construction cold joint is prevented from occurring by continuous pouring in place; pouring in a linear acceleration machine room: synchronous pouring of the inner wall and the outer wall, layered synchronous pouring of different labels, taking joint parts of the inner wall and the outer wall as boundaries, pouring from far to near, and pouring impervious parts of the outer wall preferentially, wherein slurry is continuously removed in the process, so that concrete is not accumulated; the overall layered casting height is controlled at 30 cm;
(IV) designing a mixing proportion;
(1) The concrete design requirement;
1. a concrete expansion agent;
1) The engineering basement structure is very long, and the shrinkage-compensating concrete doped with the expanding agent is used for casting and tamping;
2) The adopted expanding agent meets the technical requirements;
3) The material selection, mix proportion design, construction, maintenance, quality inspection and the like of the compensating shrinkage concrete should meet the regulations of related special regulations, specifications or construction methods; the prepared compensating shrinkage concrete is required to be controlled to be maintained in water for 14 days, the requirement of limiting expansion rate is shown in the table, and a compensating shrinkage concrete mixing ratio test is required to be made before construction, so that the design requirement is met; performing spot check on the limited expansion rate of the concrete in construction;
4) Test reference doping amount: post-pouring belt and reinforcing belt-40-60 kg/m; the rest positions are 30-50 kg/m;
5) The expanding agent is not suitable for being used in combination with the chloride-type additive, and the expanding agent should be cautious when being used in combination with the antifreezing agent;
6) The expanding agent does not contain aluminum powder, and the alkali content is less than or equal to 0.75 percent;
7) The admixture such as silica fume, zeolite powder, limestone powder, kaolin powder and the like is tested and demonstrated before the admixture such as foaming agent, accelerator, underwater non-discrete concrete admixture and the like is used together with the expanding agent;
2. adding anti-cracking fibers to the concrete;
1) The basement bottom plate, the basement outer wall and the top plate of the engineering require 0.9kg/m of polypropylene anti-cracking fiber.
2) The geometrical characteristics and main physical and mechanical index requirements of polypropylene fibers:
shape: y-shape; diameter: 18-20 μm; length of: 6 or 9mm of the diameter of the tube,
the density is 0.91g/cm, and the tensile strength is more than or equal to 400MPa;
the elastic modulus is more than or equal to 3500MPa, and the elongation at break is 15% -20%;
3) The fiber has chemical stability in the concrete mixture and hardened concrete, the strength is not reduced, the fiber is easy to disperse and uniform in the concrete mixture and cannot agglomerate; and has good bonding performance with hardened concrete;
4) When testing fiber concrete, the mixing proportion is determined according to common concrete without considering the influence of the fiber on the compressive strength of the concrete;
5) The fiber has alkali resistance, is not corroded by cement alkaline hydrate in concrete, and has chemical stability to concrete additives;
(2) Designing a concrete supply mixing proportion;
the mass concrete used in the project is produced and supplied by a commercial concrete mixing plant; the project department should carry out special mix proportion design with the concrete mixing station according to the characteristics of the mass concrete; because the structural sizes of the basement bottom plate and the wallboard of the linear accelerator machine room are large in difference, the proportion design is preferably carried out separately;
1) Ordinary silicate cement with low hydration heat is selected, and the cement strength is not lower than 42.5Mpa; the 3d hydration heat is not more than 250kJ/kg, and the 7d hydration heat is not more than 280kJ/kg; the tricalcium aluminate content should not be greater than 8%;
2) The fine aggregate is preferably middle sand, the fineness modulus is preferably more than 2.3, and the mud content is not more than 3%; the sand rate is preferably 38% -42%;
3) The non-alkali active coarse aggregate is selected, the particle size of the coarse aggregate is preferably 5.0 mm-25 mm, the particle size of the coarse aggregate can be properly selected to be large on the premise of not influencing pumping construction, the coarse aggregate is continuously graded, and the mud content is not more than 1%;
4) A certain amount of fly ash or granulated blast furnace slag powder is preferably mixed into the concrete to replace part of cement, so that the hydration heat is reduced; the class F class I or class II fly ash is preferably adopted, the mixing amount is not more than 50% of the dosage of the cementing material, the class S95 is preferably adopted as the slag powder, the specific surface area is not more than 420 square meters per kg, the mixing amount is not more than 15% of the dosage of the cementing material, and the total mixing amount of the fly ash and the slag powder is not more than 50% of the dosage of the cementing material;
5) Proper amount of additive is added into the concrete; such as retarder, for reducing early hydration heat of cement; the water reducing agent reduces the unit water consumption and the cement amount; an expanding agent fills in the gaps of cement, enhances the self-healing capacity of concrete, reduces cracks and the like; the expanding agent adopts calcium sulfoaluminate, the recommended blending amount is 10%, and the specific blending amount is determined by a test;
6) The mixing water dosage is not more than 170kg/m of the solution;
7) The water-gel ratio of the mixture is not more than 0.45, the dosage of the cementing material is preferably in the range of 320-350 kg/m, the chloride ion content is not more than 0.10% of the total amount of the cementing material, and the alkali content is not more than 3.0 kg/m;
8) The specific mixing proportion is designed and determined according to comprehensive experimental consideration by combining the principle;
a. the mixture has good workability, fluidity, cohesiveness, water retention and other properties, and the slump is 160+/-20 mm;
b. The prepared mixture has retarding time and slump loss meeting construction requirements, and the slump loss of 1 hour is less than 30mm;
c. the concrete pumping performance is improved by mixing high-quality fly ash and slag powder, the hydration heat is reduced, and the release speed of the hydration heat is delayed;
d. selecting an FST-6 polycarboxylic acid high-performance water reducer, reducing the water-cement ratio, delaying the release speed of hydration heat and improving the crack resistance of the concrete;
e. the mixing ratio is a mass concrete mixing ratio, and 60d strength is adopted as a concrete strength index;
f. according to the early production and trial-and-development experience of a laboratory, the mixing ratio of C40 and C40P8 is finally determined;
(V) supply and transportation of concrete;
1) The sand and stones in the storage bin of the concrete mixing station should be covered by sunshade;
2) The temperature of the cement entering the machine is not higher than 60 ℃;
3) Ice water can be used for mixing, so that the temperature of the concrete outlet machine is reduced;
4) The weather forecast is closely concerned, and concrete pouring construction is avoided in rainy days, particularly in stormy weather;
5) Before pouring and opening, testers and quality staff are all in place, so that the slump and the expansion degree of concrete of each truck are ensured to meet the site construction requirements; the technical data carried by technicians at the commercial mixing station reaches a construction site along with concrete produced by a first vehicle, and the technical data and site constructors monitor the workability of the concrete together to provide site technical service; the tester visually detects the slump and the expansion degree of the concrete delivered from each car, and tests the slump and the expansion degree when necessary, so as to strictly forbid delivery of unqualified products;
6) The engineering adopts commercial concrete;
7) The material transportation in the rush hours of the early night and the rush hours of the next shift should be avoided;
8) The large-volume concrete transport vehicle should have certain sun-proof measures;
9) In the transportation process, the performance of the mixture is not adjusted by adding water into the mixture; when the additive is needed to be supplemented for adjustment, the stirring transport vehicle should stir rapidly, and the stirring time should not be less than 120s;
10 When slump loss or segregation is serious in the transportation process, pouring into a mould is not needed when the working performance of the concrete mixture cannot be recovered by taking measures;
11 The concrete amount of the engineering is large, the pouring time is long, and traffic is dredged in time;
pouring and vibrating concrete;
1) The engineering linear accelerator machine room is preferably constructed by adopting integral layered pouring; the layering thickness is 300mm and is not more than 1.25 times longer than the vibrating rod, and the interlayer intermittent time is not more than the initial setting time of the concrete; in the pouring process of each layer of concrete, a method of 'one gradient, thin layer pouring, timely vibrating and one-time top' is adopted, so that the continuous pouring of a thick bottom plate is ensured, the occurrence of construction cold joints is avoided, the radiating surface of the concrete is increased as much as possible, and the early-stage concrete hydration heat dissipation is facilitated;
2) The on-site scheduling management is reinforced when the concrete is poured, so that the poured concrete is covered by the upper layer concrete before initial setting and no cold joint is generated;
3) In the pouring process, the performance of the concrete is not required to be adjusted by adding water into the concrete; the concrete slump must be tested for each car, a tester is responsible for testing the concrete slump constructed on the day, constructors test the slump of each car, and is responsible for checking whether the slump of each car meets the technical requirements of commercial concrete tickets and making slump test records; the slump of the mixture is preferably controlled to be 120-160 mm, and the maximum slump cannot exceed 180mm; if the concrete cannot reach the construction conditions, immediately returning to the concrete mixing station;
4) The temperature of the concrete in the mould is controlled to be 5-30 ℃, and when the conditions permit, the concrete pouring is avoided in a high-temperature period;
5) The vertical falling height of the concrete is not more than 2.0m, and when the conditions are not met, a chute or a string cylinder can be adopted for auxiliary construction;
6) Firstly, scraping the surface of the concrete by using a long scraping ruler, rolling for a plurality of times by using an iron roller before initial setting, and then polishing and compacting by using a wood trowel to close a water collecting crack;
7) In the pouring process, the conditions of the steel bars and the embedded parts are observed frequently, when deformation and displacement are found, pouring is stopped immediately, and measures are taken immediately to finish the concrete well before the poured concrete is coagulated;
8) The concrete is vibrated by using a high-frequency vibrator, the distance between inserting points of the vibrator is 1.5 times the action radius of the vibrator, the concrete is required to be quickly inserted and slowly pulled out during the vibration, and in the vibration process, a vibrating rod is slightly pulled up and down so as to uniformly vibrate up and down, and the vibrating rod is required to be inserted into the lower layer by about 50mm so as to eliminate a joint between the two layers; the vibrating time of each point is preferably 20-30S, but the concrete surface is not obviously sinking any more, no bubble is generated on the surface, and even cement paste is spread on the concrete surface; the steel bar, the template and the embedded part are forbidden to be contacted during vibration; preventing leakage vibration and over vibration;
2) After the concrete is poured, carrying out secondary vibration before the concrete approaches to initial setting for 3-4 hours, and then scraping with a scraping ruler according to elevation lines and lightly wiping and pressing;
3) The surface cement paste of the mass concrete is thicker, and the bleeding phenomenon and the floating paste are serious and should be carefully treated; the concrete surface treatment is performed with three pressing and three leveling; firstly compacting by using a clapping plate according to the elevation of the surface, and scraping by using a long scraping rule; secondly, rolling and leveling the steel plate by using an iron roller for several times before initial setting; finally, before final setting, polishing, compacting and leveling by using the wood crabs to close the water receiving cracks of the concrete; the rolling marks should be mutually connected when the iron roller rolls, and the times are respectively and vertically long and short;
Seventh, concrete surface crack prevention control measures;
after the pumped concrete is vibrated, the surface cement paste is thicker, and surface cracks are easy to cause;
firstly, when the uppermost layer of concrete is vibrated, the vibration time is controlled, and the phenomenon that a thick floating slurry layer is generated on the surface layer is avoided; after pouring and tamping, a 2m long aluminum alloy scraping rule is needed to be used for scraping off the redundant floating slurry layer in time, melon seed slices are used for wiping and pressing, and the concrete surface is scraped and beaten to be flat according to a preset elevation control point; the pit-containing part is filled with concrete, when the concrete slurry is collected to be close to the initial setting, the concrete surface is subjected to secondary trowelling, and the wood trowelling is comprehensively and carefully smeared twice, so that the flatness of the concrete is ensured, the shrinkage dehydration fine seam on the initial surface is closed, and other people except concrete constructors cannot walk on the concrete surface which is not dry and hard at will during the concrete slurry collecting and setting construction;
(eight) placing a concrete test block;
each pouring, the concrete compression-resistant test block and the impervious test block are manufactured together with a commercial concrete factory representative according to the standard requirements, and standard maintenance and on-site maintenance under the same conditions are carried out;
1) Sampling the concrete with the same mixing proportion of not more than 100m3 for each mixing of 100 plates;
2) When the concrete mixed by each working class with the same mixing ratio is less than 100 plates, sampling is not less than once;
3) When the casting is performed continuously for more than 1000 m < 3 >, the concrete with the same mixing proportion is sampled at least once every 200 m < 3 >;
4) The concrete with the same mixing proportion is sampled at least once for each floor;
5) The waterproof concrete impervious test pieces are continuously poured in the same mixing ratio, wherein one impervious test piece is reserved every 500 m < 3 >, and one impervious test piece is 6 impervious test pieces and is not less than 2 impervious test pieces;
6) At least one group of standard maintenance test pieces is reserved for each sampling;
7) The retention of the test blocks is ensured to be in charge of personnel special for project department, the weather condition and the temperature of each day must be recorded in detail by a data room under the same condition, and each group of test blocks are summarized and sent to a detection center in advance for test when the speed reaches 600 ℃/d.
10. The construction method of the medical room radiation protection concrete structure according to claim 1, characterized in that: the structural concrete curing construction specifically comprises the following steps:
1) After pouring is completed, adopting a heat preservation and moisture preservation measure of covering a film and covering geotextile; the inner wall adopts the measure of spraying maintenance with a mould, the outer wall is covered with a film and covered with geotextile for maintenance after the mould is removed, the top plate is covered with a film and geotextile for maintenance, and mortar is used for painting the back sill for water storage maintenance after the strength is reached;
2) The mass concrete should be maintained by heat preservation and moisture preservation; after the concrete is poured, covering or spraying maintenance work is needed to be carried out immediately before initial setting; maintaining the temperature for not less than 14 days; the temperature difference (without concrete shrinkage equivalent temperature) between the inner surface and the outer surface of the concrete casting body is not more than 25 ℃, the cooling rate of the concrete casting body is not more than 2.0 ℃/d, the alarm temperature is 1.5 ℃, the temperature difference between the surface of the concrete casting body and the atmosphere is not more than 20 ℃, and the alarm temperature is 18 ℃;
3) The bottom plate and the floor concrete are cured by adopting a method of covering the thin film with geotextile, adding water and retaining water for curing; the insulation coating is removed gradually in layers, and when the maximum temperature difference between the surface temperature of the concrete and the environment is less than 20 ℃, the concrete can be completely removed; spraying and curing with templates are adopted on two sides of the inner wall and the outer wall of the linear accelerator machine room, and an intelligent spraying system is used for curing for not less than 14 days;
4) The temperature difference change is effectively controlled by adopting a heat preservation and moisture preservation maintenance method;
after the concrete is finally set, a plastic film coating is adopted on the surface of the concrete, so that moisture on the surface of the concrete cannot be lost, and the upper cover geotextile is covered by heat insulation, the surface of the concrete is maintained by water storage, the wall is maintained by spraying with a mold, and the time for protecting the mass concrete is not less than 14d; ensuring that the difference between the center temperature and the surface temperature of the concrete is not more than 25 ℃;
5) A temperature control method of cooling by adopting a circulating condensate pipe is adopted;
circulating condensation water pipes are uniformly distributed in the walls and the plates of the machine room, and when the temperature difference between the inside and outside of the concrete exceeds a temperature control value, the temperature is controlled by timely passing through the condensation water, so that the temperature is prevented from rising too fast;
installing cooling water circulation cooling pipe networks between wall steel mesh sheets after binding of the machine room wall steel bars is completed and before installing the templates, and connecting the cooling water circulation cooling pipe networks by using DN40 galvanized steel pipes, wherein steel pipe risers are reliably fixed on wall steel mesh sheet additional ribs by using binding tapes; binding the reinforcing steel meshes at the middle layer of the floor slab, and horizontally installing a cooling water circulation pipe network in the floor slab by using a DN40 galvanized steel pipe; after the concrete curing period is finished, the cooling water circulation pipe network uses 1: grouting and filling high-grade expansion cement mortar of 0.5; the water pipes are arranged at intervals of 1500 in the transverse and longitudinal directions and are arranged at the central position of the wallboard;
and (3) temperature control:
1) The engineering temperature measurement adopts a JDC-2 portable electronic temperature measuring instrument to measure the temperature, and consists of a host machine and temperature measuring wires, wherein the host machine is a portable instrument and is provided with a power switch, an illumination switch, a socket and a liquid crystal display screen, the measured temperature value can be digitally displayed, the temperature measuring wires are embedded and are made of plugs, wires and temperature sensors, and each temperature measuring wire can measure one point of temperature; the temperature measuring wire is pre-buried before concrete pouring, a power switch of the host computer is pressed down when temperature measurement is completed after pouring, a plug of the temperature measuring wire is inserted into a socket of the host computer, and a display screen of the host computer can display the temperature of a corresponding temperature measuring point;
2) The large-volume concrete pouring body is responsible for heat preservation and maintenance work by special personnel, and is subjected to test records, wherein the test items are temperature difference between the inner surface and the outer surface, cooling rate and environmental temperature; the temperature measurement time interval is 2h after 1-3 d, 4-7 d is 4h after concrete pouring, and 8h after the concrete pouring; the mold entering temperature is measured, and each shift should not be less than 2 times; the temperature measurement duration time is from the time when the initial setting of the concrete pouring is finished to the time when the maximum temperature difference between the surface temperature of the concrete and the environment is measured to be less than 20 ℃, and the temperature is maintained after the removable covering, and is not less than 14d;
3) Monitoring points in the large-volume concrete casting body are arranged at the middle positions of a 3-surface thick wall with the thickness of 3000mm and a 2-block thick plate with the thickness of 2500mm, and are 5 points in total and fixed in place by adopting steel bars;
4) When measuring the temperature, firstly, using a thermometer to test and record the ambient air temperature and the temperature of the concrete surface; then, testing the temperature by using a temperature measuring instrument according to the serial number sequence of the temperature measuring points, and reading data after the display number of the temperature measuring instrument is stable during testing;
5) Recording temperature measurement data;
6) The temperature is reported every day, and the technical part makes statistics and data arrangement, and reports and manages; when the temperature measurement data is abnormal, after the problem of temperature measurement equipment is eliminated, a layer of geotextile should be additionally covered for controlling the temperature difference in an emergency way.
CN202311275280.2A 2023-09-28 2023-09-28 Construction method of medical house radiation-proof concrete structure Pending CN117385886A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118071876A (en) * 2024-04-17 2024-05-24 中国建筑西南设计研究院有限公司 Automatic sample-turning method, equipment and medium for special-shaped plate bottom ribs
CN118288386A (en) * 2024-06-06 2024-07-05 中铁四局集团有限公司 Prefabricated box Liang Liangmian cloth vibration integrated intelligent integrated control system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118071876A (en) * 2024-04-17 2024-05-24 中国建筑西南设计研究院有限公司 Automatic sample-turning method, equipment and medium for special-shaped plate bottom ribs
CN118288386A (en) * 2024-06-06 2024-07-05 中铁四局集团有限公司 Prefabricated box Liang Liangmian cloth vibration integrated intelligent integrated control system

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