CN101566010A - Compaction forming construction method of concrete poured on the base of structure and device thereof - Google Patents

Abstract

A compaction forming construction method of the concrete poured on the base of the structure and a device thereof belong to the field of civil engineering. The invention relates to the compaction forming construction method for directly pouring concrete on the lower part of prior structure and the device thereof. The method and the device of the invention are not restricted by the obstruction of the upper structure. The concrete can be extruded and pushed to a formwork to be poured and extruded to compact for forming in a horizontal direction of the side surface or a vertical direction from bottom to up. The bearing capacity of the prior structure is improved or the prior structure is reinforced. The extruding device is installed to the bottom or side surface of the existing structure. The concrete to be poured is filled in a cylinder body (4). After an extruding plate (5) is pushed for squeezing the concrete (15) forwards in the horizontal direction or upwards in the vertical direction through a force applying nut (11) or a jack, the stable pushing force is kept for extruding the new concrete to compact in one time for completing the pouring task. The device of the invention is composed of a cylinder body (4) with circular or square cross section, a piston type pushing extraction plate (5), a force transmitting screw bolt (6), the force applying nut (11), etc.

Description

The compaction forming job practices and the device of structural base concreting

Affiliated technical field

The structure such as building, bridge, tunnel, dam, liquid storage tank, silos, nuclear reactor shell body that the present invention relates to concrete structure are because of transforming or reinforce compaction forming job practices and the device that needs at existing structure bottom or side concreting.Field of civil engineering.

Background technology

Because concrete has certain trickling (slump), traditional concreting method is to found good template by the member designs shape earlier, concrete is directly toppled in the progressive die plate from top to bottom again, and vibration compacting solidifies the back and forms structural element.

In [concrete structure reinforcement design specifications] GB50367-2006, listed " increasing the strengthened section method ", promptly bent, the cross section expansion method of compressed member, with enlarged cross section at the bottom of the beam is example, standard does not point out how to build with wide newly watering partly with existing beam section, for this cross section for ease of building, must strengthen the width that newly waters part, as not removing redundance, can influence attractive in appearance after the concrete setting; Perhaps to carry out damaging cutting to redundance; Or adopt the static(al) cutting, must increase the cutting expense.

Listed other reinforcement means in [standard] generally all needs to rely on existing member section and carries out, and does not satisfy as the cross section condition, and then other measure is not taked in explanation, and the designer generally can only remove existing member and reform.And " increasing the fulcrum reinforcing method " also relates to the problem of how to build between the existing member of newly placed concrete fulcrum and top when not opening superstructure, and the increase fulcrum can cause certain obstacle to function of use.

[standard] be not to entering construction in the superstructure, in the time of promptly can not opening the top concrete structure or not remove superstructure, existing beam needs to increase under three (two sides and bottom surface) enlarged cross section or the plate concrete beam could be satisfied under the actual situation about requiring, any suggestion is not proposed, therefore, the designer at concrete structure because of reinforcement or improve in the transformation or stabilization works that bearing capacity carried out, often need build new concrete in the bottom or the side of existing structure, generally can only remove earlier and build the original structure member that the face top stops, the old and new's structure is built in the lump again.So, the one, increased investment cost, the 2nd, construction period prolongs, and the 3rd, as run into structure top and be other people property right, because of it has influence on other people the normal use to structure, also relate to the co-ordination problem.

In addition, under the situation that superstructure can not be removed, the designer be because the restriction of existing concrete job practices at present can only design the supporting member that makes new advances below distance existing structure certain distance, and employing is laid bricks or filled other lump bodies and carry out power transmission between the new and old structure; Also can newly do a girder steel, fill in the gad piece between girder steel and the top concrete structure and come power transmission in the existing structure bottom surface.Use these comparatively inadequate Scheme of Strengthening, all can not make new and old structure form overall structure, be unfavorable for the whole stressed of structure, simultaneously also very uneconomical.

Summary of the invention

(1) technical problem of required solution

(1) in building renovation or the stabilization works, the concrete building roof system that has built up needs structural strengthening or improves bearing capacity, employing is increasing concrete column under directly newly-increased concrete beam or the beam below the floor structure, or the beam technical measures that increase down concrete shear force wall are not only to have saved time but also economical approach, and structure can form whole stressed simple and direct approach again simultaneously.But realize this technical scheme, just require in the existing structure bottom casting and compacting of concrete is closely knit.Between the bonding surface of existing structure bottom and newly placed concrete, under the situation of not opening superstructure, use conventional construction method, be the concrete with certain slump can't be watered from the side to smash assigned address, the pumping of concrete of premixing particularly, the slump is fluidised form substantially more than 16cm, then can not guarantee the density of concreting, can not guarantee the tight bond combination between the new-old concrete bonding surface.Therefore, do not opening or removing superstructure, from the side of existing structure below, to intend on the pouring mouth of concreting between the basal surface of existing structure, this small space zone concrete built because of the execution conditions that do not possess conventional construction method and can not realize.

(2) dam, bridge pier, large foundation, nuclear reactor housing invar muscle are intensive, sometimes shake because of vibrate leakiness or leakage, quality accidents such as honeycomb, cave can appear, cut puff and be divided into the hole of a rule, or replenish to build and reserve the hole, these situations, common practices is the side formwork erection at existing member, and stretch out a segment distance laterally and make a funnel, funnel exceeds hole face to be built, from the inside concrete perfusion of bell mouth, treat concrete setting after, cut the unnecessary part in the hole outside.This way is effectively to more shallow hole, to darker hole, because of vibrating head touches upper surface less than inner end, hole, often make the concrete vibrating leakiness, or the air that squeezes into can not arrange, and has certain space, makes structural element still have hidden danger of quality; Cut in addition the concrete at funnel place of external surface of structural member general as after final set (10 hours) cut, because of concrete intensity very low, it strikes that cutter vibration solidifies concrete internal construction and later stage is influential, and promptly the external force vibration crystalline solid that can directly have influence on the hydration reaction in the process of theing cement solidifies forms quality; Behind 28 days freezing periods of concrete, directly strike cutter, also can damage the concrete structural performance that keeps the position, generally need could remove redundance with the static(al) cutting mode, this way must make the construction cost increase, and construction period also need have certain prolongation.

(3) at the bottom of the beam of building top board, bridge, the subterranean tunnel top comes off local concrete damage or damage because of reasons such as burn into blast, fire, earthquake, weathering, need cut porous spot and replenish concreting, these situations, if do not open superstructure, also there are not the technical method and the technological process of direct concreting at present.

(2) technical scheme

At the three class problems that run in the above-mentioned concrete structure engineering construction, the technical scheme of taking is to design three kinds to advance compacted device also to be classified, concrete is entered into template by extruding, further extruding is closely knit again in template, finish the concreting shaping work, thereby adopt the design scheme of direct concreting to pave the way during for engineered reinforcing.

(1) first kind problem collect into, the below of the concrete slab of a sealing, the problem that if can directly build out a concrete beam that closely links to each other with plate is resolved, and the beam problem that increases concrete column, beam down and increase down concrete shear force wall all will be readily solved so.Therefore, the technical measures of how to build out a concrete beam below plate have just become to solve the key of this class problem.Concrete analysis is such, the cross section of beam (section) has certain height, when setting up the template of beam, bed die with beam stands earlier, look the height situation of beam section, with the Side shuttering of beam by highly being divided into two parts, found down earlier half (first), reserve the operating space of the about 30～50cm of the upper half, in this space, be provided with one concrete advanced the compacted device be expressed to assigned address, the formation of this device is, in horizontal plane, set up the concrete platform that gathers materials of stacking at the side form top, platform two vertical planes that gather materials are established two laggings, platform gathers materials, two laggings, constitute the cylinder body of sealing at the bottom of the existing concrete plate, transversely movable piston-type extrusion plate double as is installed in the outside of the platform that gathers materials is advanced the upper half side form (second portion) after putting in place, run through continuous with Screw arbor with nut at both-ends between two stripper plates, screw the nut that stretches out on the side form outside screw rod, make stripper plate have the piston progradation, the concrete of stacking on the platform that will gather materials is advanced to the assigned address of beam section to be poured and pushes closely knit, the one-time-concreting moulding of implementation structure bottom concrete component is called for short compacting method.

Advance in the compacted process at concrete, concrete internal gas inserts electric hammer drill by the aperture that gets out in advance on the stripper plate and stirs effusion; When forming seal air cavity at the bottom of two stripper plate inner concretes pushings is increased to the original structure plate, air is discharged to outside the template by the plastic straw of predetermined fixed on the air cavity top at the bottom of the plate, and this pipe has concrete concurrently and pushes plasma discharge function when closely knit.In the stripper plate progradation, should the preformed hole stopper jam-pack of electric hammer drill will be inserted; Before stripper plate is advanced to assigned address, should in time pull out plastic pipe and seal preformed hole, guarantee the pressure that inside concrete forms, newly placed concrete and original concrete joint surface place are combined closely.

The ability to work of the compacted degree reply screw rod of stripper plate is carried out designing and calculating, and this part content is introduced in the specific embodiment.

(2) second class problems collect the problem into the additional concreting in cave, side of structural element on the existing coagulation.Here the piston-type extrusion plate that still can continue to use the front advances the compacted device of extruding, but stripper plate is not symmetrical arranged, one side only is set, run through two stripper plates to drawing afterburning screw rod to change into: screw rod will stretch into inside, cave, on the face of cave, hole, with structure glue screw rod (being chemical anchor bolts) is implanted in original concrete, overlapped upper extrusion board again, advance the requirement of compacted concrete mechanism thereby satisfy.

If bottom, cave concrete does not satisfy the condition of implanting screw rod, or the bottom, cave is open, i.e. hole of Guan Tonging, but the unapproachable situation of constructor, the inner end of afterburning screw rod should link to each other with two vertical reinforcing bars implanting respectively at top, cave, the ends two corresponding surface (or horizontal two sides).As for the setting platform that gathers materials, the technical scheme of first kind problem is still continued to use in vibration ease gas, exhaust plasma discharge etc.

It is that (seeing from bottom to top) has a recess at the bottom of the dull and stereotyped plate of a sealing that (3) the 3rd class problems collect, and needs concreting is mended flat to this recess.The solution of this class problem is, a circular or square regular hole will be reserved on the concrete bottom die to be poured, the below, hole, one circle or square piston-type extrusion are installed advance compacted device, the shell of this device is that a steel pipe close with dimension of opening is as cylinder body, one bell mouth of cylinder body arranged outside, as concrete charging aperture, insert piston plate in the steel pipe from bottom to top, piston plate moves upward and concrete is advanced in the caveli of concrete slab on top and compacted, the boosting-rod of piston is a screw rod, and screw rod can be used the swivel nut jacking, also available jack jacking.

(4), from job practices, install purposes, divide classification in detail, list table 1 according to above-mentioned three kinds of technical schemes.

Table 1: compacted device classification

(3) beneficial effect

(1) needn't remove existing structure, change traditional form of construction work of concreting from the top down, save the expense of transformation or stabilization works.

(2) engineered or reinforcing design scheme becomes comparatively simple, needn't seek other expensive reinforcement means.

(3) the New-old concrete structure is built and is same integral body, and is stressed clear and definite, calculates simple.

(4) construction period shortens dramatically, and only the part of needs transformation or reinforcing is constructed; Build the side, and the no unnecessary material filling notch portion of widening need cut and repair.

(5) increase the apparatus of building under the series of concrete specified conditions.

(6) expand and the further perfect technical method and the construction technology of field of civil engineering concrete series pouring construction.

Description of drawings and embodiment

(1) description of drawings

Corresponding aforesaid three kinds of technical schemes, wherein accompanying drawing 1,2 is first kind of scheme, and accompanying drawing 3,4 is second kind of scheme, and accompanying drawing 5,6 is the third scheme.

Accompanying drawing 1 is that the concreting extruding of the newly-increased beam of concrete slab or beam below advances compacting apparatus.Accompanying drawing 2 is the I-I section of accompanying drawing 1.

In the accompanying drawing 1: (1) is existing structure concrete slab or beam; (2) be newly-increased concrete beam bottom surface template; (3) be the following half Side shuttering of newly-increased beam; (4) be to pile up the concrete platform that gathers materials; (5) be the piston-type extrusion pushing plate, double as advances the upper half template after putting in place; (6) be Screw arbor with nut at both-ends to the stripper plate reinforcing; (7) be afterburning nut; (8) be billet; (9) be the vibration hole of pre-drilled insertion electric hammer drill, double as plasma discharge hole; (10) be exhaust plasma discharge plastic flexible pipe; (11) be the nailing of fixed plastics flexible pipe; (12) be the PVC sleeve pipe, be convenient to Screw arbor with nut at both-ends and extract repeated use; (13) be stop nut; (14) be stopper, the compacted rear defence sealing mud loss that puts in place of concrete; (15) be newly placed concrete.(18) be reinforcing cage.

In the accompanying drawing 2: (16) are laggings; (17) be diaphragm.

Accompanying drawing 3 replenishes the compacted device of concreting moulding for existing cave, concrete structure side, but the situation of cave inner end plant crab-bolt.

In the accompanying drawing 3: (1) is existing concrete structure member; (2) be to pile up the concrete platform that gathers materials; (3) be to go up the cover template; (4) be the piston-like movement stripper plate, the template after double as is compacted; (5) be billet; (6) be screw rod; (7) be afterburning nut; (8) be the chemical anchor bolts part of screw rod; (9) be stop nut; (10) vibration and plasma discharge hole; (11) be stopper; (12) be plastic flexible pipe; (13) be nailing; (14) be newly placed concrete; (15) be lagging; (16) be that template supports.

Accompanying drawing 4 replenishes the compacted device of moulding of concreting for existing cave, concrete structure member side, the cave inner end does not have plant crab-bolt condition, be that the inner end concrete is thinner, or when not having concrete surface, can only carry out bar planting in the side, cave, promptly the side, cave up and down or about the boring structure glue of symmetric position carry out bar planting.

In the accompanying drawing 4: (1) is existing concrete structure member; (2) be to pile up the concrete platform that gathers materials; (3) be to go up the cover template; (4) be lagging; (5) be the piston-like movement stripper plate, promptly double as advances the Side shuttering after putting in place; (6) be billet; (7) be screw rod; (8) be afterburning nut; (9) be to connect steel plate; (10) be main connecting angle; (11) be secondary connecting angle: (12) are connecting bolts: (13) are bar plantings; (14) be plastic flexible pipe; (15) be the fixing nailing of flexible pipe; (16) be stop nut; (17) be vibration and plasma discharge hole; (18) be stopper; (19) be newly placed concrete; (20) be that template supports.

Accompanying drawing 5 is the concrete afterburning compacted device that advances and return of screw rod from bottom to top, and concrete pours into from charging aperture, through repeatedly move back and forth up and down recess at the bottom of being pressed to upper board of piston-type extrusion plate, final compaction forming.

In the accompanying drawing 5: (1) is existing concrete slab; (2) be recess; (3) be the bottom template; (4) be cylinder body; (5) be the piston-like movement stripper plate; (6) be dowel bar; (7) be feed hopper; (8) be the charging aperture gate; (9) be the discharging opening gate.(10) be upper padding plate; (11) be afterburning nut; (12) be lower bolster; (13) be backlash nut; (14) be force transmission rack; (15) be the concrete that adds.

Accompanying drawing 6 is the compacted device of moulding that recess replenishes concreting at the bottom of the dull and stereotyped plate, this device is divided into the afterburning and afterburning dual mode of jack of screw rod to the reinforcing of piston-like movement plate, uses specifically that any will to look size and afterburning numerical value that unit in charge of construction has any equipment, construction volume definite.Drawn in the accompanying drawing 6 diagram of jack reinforcing.

In the accompanying drawing 6: (1) is existing concrete slab; (2) recess to be built; (3) be newly placed concrete; (4) be steel pipe support (scaffold); (5) be the channel-section steel joist; (6) for being with the jack of oil pressure gauge; (7) be the dowel bar base plate; (8) be stiffening rib; (9) be nut, dowel bar is return; (10) be billet; (11) be dowel bar, the screw rod when adopting direct reinforcing of nut (13) or locking; (12) power transmission steel rigid frame, horizontal segment are welded to each other by 2 No. 8 channel-section steels and form, and the every side of vertical section is 1 No. 10 channel-section steel; 8, No. 10 channel-section steels are welded into integral body; Lock nut when (13) being the jack reinforcing, lock nut does not glide when shifting certain position onto on the stripper plate; Or be the afterburning nut of screw rod when afterburning; (14) be that circle or square piston advance steel plate; (15) be the caulking gum sheet; (16) be the circular or square compressed steel plate of going up; (17) be bolt, (14), (15), (16), (17) constitute piston and advance the stripper plate assembly; (18) be round steel pipe or square steel pipe, as the working cylinder of piston pushing plate, steel pipe and the weldering of bottom power transmission rigid frame are for whole; (19) be the concrete in advancing; (20) be the concrete feed hopper; (21) be concrete charging aperture gate steel plate, seal in the piston pushing plate progradation; (22) be cylinder body upper end intake and exhaust tube heads, there is internal thread the tube head outer end; (23) be the blind bolt of tube head; (24) be tube connector; (25) be the flange of cylinder body upper end; (26) be the lower flange of cylinder head; (27) be the sealing outer tube of last lower flange; (28) be the upper flange plate of cylinder head; (29) be discharging opening gate steel plate, steel plate intert in cylinder head in the slit between the lower flange; (30) open power transmission transverse slat on the discharging opening gate steel plate, transverse slat thickness is no less than 10mm, and gets out internal thread hole, screws in for the advance and retreat screw rod; (31) be the power transmission floor; (32) be the advance and retreat screw rods, the right part is screw head and handle; (33) for being screwed in the double nut of advance and retreat screw rod left part, double nut is further divided into left and right sides nut, after right nut is twisted well, with electric welding nut and screw rod hoop are welded, with file screw thread between the space of two nuts is rasped to round slip surface, again the screw rod left end is inserted in the circular hole of steel plate (41), left nut is screwed on the screw rod, with electric welding left nut and screw rod are welded along hoop, rotary handle or screw head can make the discharge gate steel plate open and close again; (34) be the junction plate of steel plate (42) and cylinder body (18); (35) be the connecting bolt that is welded on the cylinder head lower flange; (36) be nut on the connecting bolt of cylinder body and cylinder head; (37) be that the bar reinforcement that passes through template passes the function of shaking, the bubble in the effusion concrete that shakes for vibration; (38) exhaust plasma discharge plastic flexible pipe; (39) nailing of fixed plastics flexible pipe; (40) be concrete base template to be poured.

(2) embodiment

The lawn that Nanjing China's light milky way gulf entrance, sub-district initial stage is planned to build into the square formula, underground is the parking lot, make civil air defense constructions and installations wartime, the developer is subsequently for improving the quality of this sub-district, the lawn scheme is changed into pile up mound, transplant the trees flowers, set up the pond, foot bridge, flowing water, road, etc. landscape planting.Needs when opening the set because of the sub-district, basement top earthing view has been caught up with to rob and has been finished, and basement roof does not have enough time to reinforce, and supports with full hall scaffold temporarily.This basement is a frame shear wall structure, the earthing that bears was only thick for 0.7m originally, and existing earthing reaches about 2.3m, and the load increase is bigger, floor structure is reinforced, and design scheme needs a part of beam, post are adopted enlarged cross section and the plate method for designing of newly-increased a part of beam column built from concrete down.The difficult point of this project is that cast-in-place plate does not allow to remove even punch, and the plate below need be built with raw sheet and is linked as whole beam column, with the opposing blast impulse load in wartime.For this reason, we adopt compacted device to implement, and promptly a concrete beam that is connected as a single entity with upper board with direct compacted method, is built out in the concrete slab of sealing below, and compacted device as shown in Figure 1; Beam, column section enlarge and the position that links to each other at the bottom of the plate, also adopt this method to carry out pouring construction, and compacted device as shown in Figure 3.This project is not because of shedding earthing, dismantling concrete beam slab not, and the duration saved 4 months, and cost is saved 6,000,000 yuan of about RMB.Publication that the paper of this embodiment " has increased the research of air's structural strengthening design of view load and construction technique " is on 2008 o. 11th " industrial construction ".

The specific embodiment

(1) design part

The compacted device of piston-like movement is mainly formed by depositing concrete sealing template chamber of propelling or cylinder body, stripper plate, screw rod etc.Screw rod as reinforcing usefulness needs to overcome concrete viscosity resistance (when boosting, containing gravity) in progradation; Nut self-locking when propelling puts in place; For guaranteeing combining closely of concrete density and new-old concrete interface, newly placed concrete should have certain internal pressure stress.

(1) concrete horizontal advances the resistance in the compacted process to be determined by concrete viscous force R (N), viscous force is by the angle of internal friction of coarse aggregate, the viscosity resistance decision of coarse aggregate extruding lifting, write according to Jiang Zhengrong, Zhu Guojun, by publish China Construction Industry Press in July, 1999 " during simple and clear calculation on Construction handbook (second edition) propelling stroke am, pipe inner concrete viscous force R formula:

$R=\frac{2a}{r}(3.0-0.01S)\×{10}^2\left(N\right)---\left(1\right)$

Wherein r is pipe radius (m), and S is the slump (cm), in the time of straight up, and caliber 150mm, multiplying factor 5.Constitute the square-section cylinder body of sealing by former concrete slab bottom surface and both sides, bed die, after being converted to circular cross-sectional area again by a plurality of circular arrangement behind the cylinder body cross sectional area, multiply by 1.5 times of coefficients of irregularity again

(2) the afterburning screw rod of the piston plate of circular cross-section cylinder body generally only is single screw rod, and cylinder body afterburning screw rod in square-section is vertical with side of cylinder block for guaranteeing the pushing plate face, then adopts twin-screw or four screw rods to push propelling simultaneously.The design of single afterburning screw rod:

A. swivel nut overcomes that the required torque T of resistance is in the screw thread:

$T=Q\tan (\mathrm{\&lambda;}+{\mathrm{\&rho;}}_v)\frac{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="A20091013250100171.png,A20091013250100172.png"\; state="\{\{state\}\}">d</figure-callout>}}_2}{2}---\left(2\right)$

Wherein: Q is thrust (clamping force), and λ is a lift angle, ρ _vBe angle of friction, d ₂Be footpath in the screw rod.

$\tan \mathrm{\&lambda;}=\frac{S_0}{{\mathrm{\&pi;<figure-callout\; id="2"\; label="d"\; filenames="A20091013250100171.png,A20091013250100172.png"\; state="\{\{state\}\}">d</figure-callout>}}_2}=\frac{\mathrm{zp}}{\mathrm{\&pi;}{d}_2}---\left(3\right)$

Wherein: S ₀Be helical pitch, z is the line number of screw thread, and p is a pitch.

The tooth form oblique angle of standard coarse plain thread:

$\mathrm{\&gamma;}=\frac{\mathrm{\&alpha;}}{2}---\left(4\right)$

Wherein: tooth form angle α=60 °.

The pass of angle of friction, tooth form oblique angle, friction factor f is:

$\tan {\mathrm{\&rho;}}_v=\frac{f}{\cos \mathrm{\&gamma;}}---\left(5\right)$

Act on the torque capacity on the screw rod:

T＝F _maxl (6)

Wherein: l is for manually applying the effective radius of power, and is accurate for guaranteeing the power value that applies, and uses the spring scale application of force.

Maximum clamping force is propulsive force Q:

$Q=\frac{2T}{\tan (\mathrm{\&lambda;}+{\mathrm{\&rho;}}_v)d_2}---\left(7\right)$

B. behind the nut screwing clamping, the condition of self-locking of screw pair is:

λ≤ρ _v (8)

(3) afterburning screw rod draw, the checking computations of compressive stress

${\mathrm{\&sigma;}}_s=\frac{Q}{\frac{\mathrm{\&pi;}{{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="A20091013250100171.png"\; state="\{\{state\}\}">d</figure-callout>}}_1}^2}{4}}\&le;f_s(N/{\mathrm{mm}}^2)---\left(9\right)$

Wherein, f _sBe the design strength value of steel, d ₁Be the screw rod path.

Thrust-drag margin F is:

F＝nQ-R (10)

Wherein, not reduction of pressure surface is taken advantage of 0.9 coefficient perpendicular to the side pressure surface of pressure surface; N is a screw rod quantity.

New-old concrete compressive stress at the interface is σ _c:

${\mathrm{\&sigma;}}_c=\frac{F}{A}(N/{\mathrm{mm}}^2)---\left(11\right)$

Wherein: A is the stripper plate area.

The unrestricted condition of the concrete free lifting height H that is squeezed at the interface _Z:

$H_Z=\frac{{\mathrm{\&sigma;}}_c}{{\mathrm{\&sigma;}}_z}\left(m\right)---\left(12\right)$

Wherein: σ _zBe the attach most importance to compression stress ot of concrete 1m when high _z=γ _cH=0.024N/mm ²

New-old concrete compressive stress at the interface be influence the concrete of newly building can with former concrete tight bond key index together, but when this value is too big, to produce very big pressure to template system, support system, this just causes construction cost to rise, for the influence degree of this index is described, it is converted into concrete deadweight height, the promptly unrestricted condition free lifting height H that is squeezed _z, just can reflect more intuitively.

For making concrete both build closely knitly, be unlikely to template again, support the too big pressure of generation, H _zUsually value is between 1.5～2.5m, and certainly, this value neither be absolute, and when certain experience was arranged, this value also can be smaller again, but to guarantee that closely knit between the new-old concrete is principle.

Therefore, the design of afterburning screw rod, processing and manufacturing, act on torque on the spanner, be that the product etc. of the length of the size of power and the arm of force is the key factor of decision concreting compaction rate.

, introduce the calculated examples of two afterburning screw rods here, example 1 is the afterburning screw rod of square-section cylinder body, and example 2 is the afterburning screw rod of circular cross-section cylinder body.

Example 1: the long 1.0m of stripper plate, high 0.3m, the deck-siding of being built is 0.5m, and every side stripper plate level is to full cylinder advance distance a=0.25m, and concrete slump 16cm selects twin-screw M12 for use, Q235 steel, double thread z=2, pitch p=1.75mm, middle footpath d ₂=10.863mm, path d ₁=10.106mm, the standard coarse thread, friction factor f=0.15 acts on the power F on the spanner _Max=100N,, arm of force effective radius l=500mm.

Example 2: φ 150mm circular cross-section cylinder body, the compacted 1m that boosts selects single screw rod M16 for use, Q345 steel, middle footpath d ₂=14.701mm, path d ₁=13.835mm acts on the power F on the spanner _Max=144N, arm of force effective radius l=500mm, other parameter is with example 1.

Tabulation is calculated, and table 2 is the afterburning screw rod design calculation process of the compacted propelling concreting of piston type moulding and the internal pressure stress of newly placed concrete.

Afterburning screw rod design of table 2:M12, M16 and concrete internal pressure stress

(2) construction part

(1) mode one, the former concrete slab below of a sealing, cast-in-placely go out a concrete beam, according to accompanying drawing 1, (1) ejects the sideline, the outside (deck-siding and two stripper plate thickness sums) of the beam side of precoating at the bottom of original plate, and the vertical graduation mark (spacing 1cm) that marks stripper plate (5) propelling process with the side line, with control propelling process; Upright good beam bottom board (2), assembling reinforcement cage (18), prop up and make half Side shuttering (3), the platform that gathers materials (4) of the upright level of bogie side frame outside side form (3) suitable for reading, beam length is being told multistage about by about 1m on the flat upper surface of gathering materials, lagging (16) and diaphragm (17) are set between every section, lagging (16), diaphragm (17) up and down respectively with (1) at the bottom of the former concrete slab, the flat upper surface of gathering materials (4) is fixing, platform (4) gathers materials, lagging (16), diaphragm (17), (1) constitutes the cylinder body of the square-section of sealing at the bottom of the former concrete slab, reinforcing value according to the screw rod design processes afterburning screw rod (6), amount of concrete to be poured (surpassing 3%～5% approximately) is deposited on the platform that gathers materials, use "T"-shaped push pedal, manually concrete (15) is shifted onto in the template and as far as possible and heaped; Afterburning screw rod puts pvc pipe (12), two stop nuts (13) of screwing on again, and the thickness sum of the length of pvc pipe and two stop nuts is deck-siding to be poured, and the effect of pvc pipe can be extracted afterburning screw rod after concrete setting, reuse; Afterburning screw rod is disposed across on the beam section, stripper plate (5) is through on the afterburning screw rod (6), the stripper plate side is every the vibration hole (9) of 15～20cm boring insertion electric hammer drill; Screw rod stretches out the stripper plate Outboard Sections and puts billet (8), screw afterburning nut (7), two row stripper plates (5) to both sides push propelling simultaneously, when the process graduation mark of stripper plate at the bottom of the former concrete slab during near the sideline, the outside of template, from preformed hole (9) the insertion electric hammer drill and the power-on of template face concrete bodies is stirred, bubble in the concrete is overflowed, plastic flexible pipe at the bottom of the gas slave plate (10) is discharged, continue pushing and vibration, the concrete that makes unnecessary volume is by in exhaust, discharge pipe and the adjacent vibration hole cement paste being discharged; For making extruding closely knit, control the numerical value of afterburning nut torque well, accurate reinforcing reaches the design load of power to spanner with spring scale.In to concrete extrusion process, gradually use stopper (14) to stop up vibration hole (9), finally extract plastic flexible pipe (10), stop up the hole that passes through plastic pipe on the stripper plate face with stopper equally, and retention nut makes the concrete extruding closely knit to the steady pressure of stripper plate.

It should be noted that, concrete blinding to be poured, support, top original structure plate all need to bear extruding institute externally applied forces, the dismounting of concrete side template to be poured simultaneously, because of concrete has been applied in certain built-in compressive stress, need after concrete possesses certain intensity, can carry out, carry out getting final product as for work such as form removal maintenances according to existing " concrete structure engineering construction quality standards of acceptance " GB50204.

(2) mode two, replenish concreting in the time of can implanting the situation of screw rod on cave, the side inner end of existing concrete structure member, according to diagram 3, loose concrete in the cave is removed and rinsed well, the cave inner end is dug out the plane of rule as far as possible, the rectangle of rule is dug out at the hole, in cave end face fixedly exhaust plasma discharge plastic flexible pipe (12) of nailing (13), on the inner end of cave, hole, drilling depth is generally waits to plant screw rod 10d, aperture d+4mm dips in absolute alcohol or acetone with rayon balls institute's boring is cleaned up, and with structure glue screw rod (6) is implanted in the hole, screw rod is by designing requirement processing, template is set in cave mouth place supports (16), set up the platform that gathers materials (2), lagging (15), last envelope template (3) constitutes cylinder body; Concrete to be poured (14) is deposited on the platform that gathers materials (2), volume of concrete exceeds 3%～5% of amount to be poured, again stop nut (9) is screwed on the afterburning screw rod (6), at last stripper plate (4) double as Side shuttering is set on the afterburning screw rod, load onto billet (5), the afterburning nut (7) of screwing on, beginning pushing gets into, in the progradation, with in the electric hammer drill insertion vibration hole vibrated in the concrete being overflowed, escaping gas is discharged through the plastic flexible pipe (12) at top, cave, increasing along with propulsive force, cement paste is from the vibration hole, flow out in the exhaust hose, should use stopper (11) shutoff vibration hole gradually, extract plastic pipe (12) at last, also with the hole of passing through of plastic pipe on the stopper shutoff stripper plate, simultaneously afterburning nut (7) is pressurized to design load, afterburning method is no longer repeated here by the aforementioned spring scale that can be.Afterburning screw rod can not be reused in this method, uses the angle sander after the form removal and cuts off, and screws out stop nut, mends the Ping Keng hole with cement mortar.

As be circular hole, the compacted propulsion plant horizontal positioned construction of the round cylinder body in the available mode of introducing below (four), this device removes feed hopper and changes into straight up, and all the other are constant; Because of jack generally is difficult for putting, afterburning mode is generally the fastening nut reinforcing.

(3) mode three, and is thin or do not have situation such as concrete surface as the inner end concrete in the time of can not bar planting on the concrete surface of inner end, teeming cave, then adopts the shaped device of accompanying drawing 4.Remove inner end in this device and implant the side implantation reinforcing bar that chemical screw rod changes the cave into, all the other are all identical with mode (two).

Specific practice is: reinforcing bar to be planted (13) is welded together with secondary connecting angle (11) in advance, main connecting angle (10) (bigger than secondary angle steel), connection steel plate (9), afterburning screw rod (7) weld together, hole in the cave medial surface, implant reinforcing bar (13), again the major-minor connecting angle is connected as a single entity with bolt (12), constitute force transfer system, all the other construction sequences and technological process and mode (two) are no longer repeated together.

(4) mode four, and recess replenishes the compacted device of moulding of concreting at the bottom of the dull and stereotyped plate, and accompanying drawing 6 installs the jack (6) by reinforcing, cylinder body (18), and piston-like movement stripper plate (14), cylinder head (26) is formed; Without jack, the also available dowel bar that links to each other with stripper plate (11) is screwed the afterburning and self-locking of nut (13).

When the concrete of place's recess is compacted put in place after, unload the connecting bolt (36) at lower cylinder body and cylinder head place, cylinder body moves to next place and uses, and could dismantle when cylinder head then should be treated the concrete setting collapsible die.

Concrete construction sequence is: set up scaffold earlier, manually cut and clean out the float stone in the depression, loose block, water washes down again; Fix with the plastic flexible pipe (38) of nailing (39) in recessed top the exhaust plasma discharge; Set up the bottom surface template of recess; Set up steel pipe support (4) is installed, cylinder head part (26～28) is placed on the top of support (4), hold out against with upper mould; Channel-section steel (5) is placed in bottom at support, places the jack of band oil pressure gauge on the channel-section steel; Cylinder body (18) assembly and cylinder head (26) are connected with bolt (36); Open gate (21) and cylinder head upper lock gate (29) on the cylinder body; Penetration concrete in feed hopper (20) shuts gate (21), presses jack (6) jacking reinforcing, notices that the backlash nut (9) on screw rod this moment need go downwards to certain position, can not hinder the work of power transmission screw rod; As then screwing afterburning nut (13) for the screw rod reinforcing, the concrete in the cylinder body is pushed through in the caveli at the bottom of the plate, insert gate (29), unclamp exhaust opening bolt (23), return jack (6), the backlash nut on the rotary screw (9), the stripper plate of backing off (14); Carry out feeding in raw material the second time, shut gate (21), secondary is pushed, when having cement paste to extrude in stack (22) mouth, (23) then tight a bolt, pull out gate (29), be expressed to concrete in the caveli once more, repeated multiple times when plastic flexible pipe (38) flows out cement paste, is extracted flexible pipe (38), stop up the passage of flexible pipe on template, continuation is applied to till the extruding thrust of design with jack or afterburning nut, shuts gate (28), turn nut (36), cylinder body is unloaded, move to next place's construction.The afterburning available spanner of nut, spring scale are implemented, and the jack reinforcing can be according to the Numerical Control in the calibrating table of jack " oil pressure reading-Li value ".

In the time of in concrete is pushed through caveli, carry out the flank attack vibration to passing shake reinforcing bar (37), the bubble effusion in the concrete is risen, discharge through plastic flexible pipe with the small vibrating rod.When treating concrete setting, dismantle cylinder head gradually, template, support, water seasoning concrete to detachable template.

(5) mode five, and recess replenishes the compacted device of moulding of concreting at the bottom of the dull and stereotyped plate, accompanying drawing 5, and stripper plate changes screw rod (6), the afterburning propelling of nut (11) into by jack, is return by screw rod (6), nut (13).

(6) mode six, for satisfying the needs that add in a large number with improvement project, also for improving the efficient of producing, change the manual jack (6) in the accompanying drawing 6 into electric oil pump jack (hydraulic control one-way valve of band oil pressure gauge and pressurize effect), directly produce the approved product of the compacted device of piston-like movement concreting by factory, " the QF type separate type oil pump jack " that the electric oil pump jack can adopt Shanghai Hoisting Jack Factory to produce, model are series such as " QF20T-20 ".

Claims (1)

1, the compaction forming job practices and the device of structural base concreting, in the concrete structure reinforcement design, existing member is taked enlarged cross section or increased supporting member is that a kind of technology is simple, stressed reliable, the reinforcement means of advantages such as the reinforcing expense is cheap, but it requires to open or remove the existing structure that top stops concreting, otherwise concrete can't from up to down water, maybe need excise the member that is reinforced because of unnecessary pouring notch portion is arranged, as enlarged cross section at the bottom of the beam, its both sides exceed newly watering partly or damaging cutting of former deck-siding, the static(al) cutting could keep the regular shape in cross section, and superstructure is forbidden to open or remove, the Scheme of Strengthening that must be close to the superstructure concreting does not again also have job practices to implement at present; The feature of this method and device is to build new concrete not need to remove superstructure, directly the concrete extruding is advanced in the template of member to be poured, a compaction forming, no redundance needs excision, be specially concrete to be poured is poured in the cylinder body (4) of circle or square-section in advance, insert piston-like movement stripper plate (5), the concrete propelling is expressed in the template of member to be poured, the afterburning value of control makes concrete have certain internal pressure stress, reach and once push closely knit molding effect, stripper plate links to each other with screw rod (6), screw rod is afterburning or single bolt and nut (11) reinforcing of Screw arbor with nut at both-ends, the screw pair self-locking conditions satisfied, the electronic or manual jack reinforcing of the also available band oil pressure gauge of single screw rod.

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