CN112536896A

CN112536896A - Ring-axis symmetric supporting-fixing type hollow slab core mold construction process

Info

Publication number: CN112536896A
Application number: CN201910909697.7A
Authority: CN
Inventors: 于凤河; 陈常友; 王海峰
Original assignee: Heilongjiang Nongken Highway Bridge Project Co ltd
Current assignee: Heilongjiang Nongken Highway Bridge Project Co ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2021-03-23

Abstract

The invention relates to a construction process of a ring axisymmetric supported hollow slab core mold, which comprises the following steps: the method comprises the following steps of core mold support type framework manufacturing (1) → core mold template manufacturing (2) → core mold assembling (3) → hollow slab core mold fixing and mounting positioning (4) → hollow slab casting (5) → hollow slab curing (6) → core mold extraction and effect testing (7). The core mould has simple structure and ingenious conception, changes the traditional disposable core mould into the core mould which can be used for a plurality of times, can be used for the prefabrication production of hollow plate beams with various shapes such as multi-prismatic shapes, circular shapes and the like, and saves labor and force and improves the benefit.

Description

Ring-axis symmetric supporting-fixing type hollow slab core mold construction process

The technical field is as follows:

the invention relates to prefabrication production of hollow slab beams, in particular to a construction process of a ring axis symmetric supported hollow slab core mold.

Background art:

generally, a traditional polygonal hollow slab core mold, particularly a hollow slab core mold of about 20m, is a disposable template formed by splicing narrow wood strips according to the structural size, and each hollow slab beam is processed into a set of core mold. The construction method takes time and materials, reduces the construction progress and increases the construction cost.

The invention content is as follows:

in order to overcome the defects in the prior art, the invention provides a circular symmetry supporting and fixing type core mold construction process for a concrete hollow slab, which can be recycled and practical.

The technical scheme adopted by the invention is as follows:

core mold supporting type framework manufacturing → core mold template manufacturing → core mold assembling → core mold fixing and positioning of the hollow plate → hollow plate casting → curing of the hollow plate in a curing way → core mold extraction and effect testing.

The core mould supporting skeleton includes three parts of central shaft, supporting parts and pull rod, and when it is used, the central shaft is folded to form a circular centre, the supporting parts are supported by the pull rod to form core mould, and when it is not used, the pull rod can be taken out, and the supporting parts can be successively inclined toward one side of central shaft.

The core mould plate is made and clamped on the edge of the supporting component, and the ring periphery is closed.

The number of the core mould templates is the same as the row number of the supporting parts on the core mould supporting framework.

The invention has the advantages that:

1. the core mould described by the process has a simple structural form and a smart concept; meanwhile, raw materials for manufacturing are easy to purchase, and processing operation procedures are easy to master.

2. The original traditional disposable core mould is changed into a circular-axis-symmetric erected type stable, detachable and extractable reusable core mould which can be remodeled and changed in length, so that the construction is convenient, the energy is saved, the construction progress is accelerated, and the economic and social benefits are improved.

3. The temporary occupied area is reduced, and the working hour cost, the material cost and the mechanical cost for processing and manufacturing the template are reduced. Not only reduces the construction cost, but also plays a great role in environmental protection.

4. Simple structure, easy dismounting, the transportation of being convenient for.

5. With the continuous maturity and improvement of the process technology, the manufacturing method of the ring-axis symmetric supported core mold can be gradually popularized.

The specific implementation mode is as follows:

1. a construction process of a ring-axis symmetric supported hollow slab core mold comprises the following steps: the method comprises the following steps of core mold support type framework manufacturing (1) → core mold template manufacturing (2) → core mold assembling (3) → hollow slab core mold fixing and mounting positioning (4) → hollow slab casting (5) → hollow slab curing (6) → core mold extraction and effect testing (7).

2. The construction process of the annular axisymmetric supported hollow slab core mold according to claim 1, characterized in that: the core mould supporting type framework manufacturing (1) comprises a middle shaft, a supporting part and a pull rod, when in use, a hinge on the middle shaft is taken as a circle center, the supporting part is supported to form a core mould under the action of the pull rod, and when the core mould supporting type framework is not used, the pull rod is taken out, and the supporting part is sequentially inclined towards one side of the middle shaft.

3. The construction process of the annular axisymmetric supported hollow slab core mold according to claim 1, characterized in that: the core mould template is made (2) and is clamped on the edge of the support component to form a ring-shaped peripheral closing body.

4. The construction process of the annular axisymmetric supported hollow slab core mold according to claim 1, characterized in that: the number of the core mould templates (2) is the same as the number of rows of the supporting parts on the core mould supporting framework manufacturing (1).

Description of the drawings:

FIG. 1: hollow slab core mould construction process flow block diagram

FIG. 2: center shaft structure form

FIG. 3: structure of core mould supporting frame and side mould plate

FIG. 4: steel support and pine tree structure sketch map

FIG. 5: schematic diagram of core mold assembling structure

FIG. 6: schematic section structure of hollow slab core mold

Application example:

1. introduction to the word

With the rapid development of transportation in various regions of China, bridges in the form of hollow slab structures are increasingly applied to highway construction.

In recent years, in the process of constructing a plurality of hollow slab bridges, the structural form of the hollow slab bridge is carefully analyzed, a large amount of construction experience is accumulated, and the construction method is popularized and popularized in companies and achieves good effects. Therefore, we summarize the method to form the method.

2. Process characteristics

2.1 the core mould structure described by the process has simple form and ingenious conception; meanwhile, raw materials for manufacturing are easy to purchase, and processing operation procedures are easy to master.

2.2 the original traditional disposable core mould is changed into a circular-axis-symmetric erected type stable, detachable and removable reusable core mould which can be remodeled and changed in length, so that the construction is convenient, the energy is saved, the construction progress is accelerated, and the economic and social benefits are improved.

2.3, the temporary occupied area is reduced, and the working hour cost, the material cost and the mechanical cost for processing and manufacturing the template are reduced. Not only reduces the construction cost, but also plays a great role in environmental protection.

2.4 simple structure, easy dismounting, the transportation of being convenient for.

2.5 with the continuous maturity and improvement of the process technology, the manufacturing method of the ring-axis symmetric supported core mold will be gradually popularized.

3. Application scope

The method is suitable for prefabricating hollow plate beams with the length of 13-25m, such as round holes, regular polygonal holes or flat polygonal holes.

4. Principle of the process

Planning and designing the structural size and the manufacturing quantity of the core mold according to a bridge construction drawing, calculating the material consumption, then processing and manufacturing each part of the structure by a template team according to a planned and designed structure diagram, and splicing, correcting and reinforcing each part into a core mold whole after the manufacturing of each part is finished so that the structural size of the formed core mold meets the standard requirement.

After the core mould structure is corrected and inspected to be qualified, the core mould structure is manually matched with machine tools to be moved and transported, placed to the specific position of the hollow slab to be poured and reinforced.

And after the concrete pouring of the hollow slab is finished and certain strength is achieved, the core mold is immediately detached. Then correcting and maintaining the hollow plate girder, quickly assembling and forming the hollow plate girder, and then prefabricating the next hollow plate girder.

5. Construction process flow

5.1 construction process flow: (see attached FIG. 1)

The construction process mainly comprises the following steps: construction preparation → welding of a core mold support type framework → manufacturing of a core mold side template → assembling of a core mold → moving and transporting of the core mold → installation of the core mold → extraction of the core mold → transfer to the construction of the next slab beam.

5.2 operating points

5.2.1 preparation of construction

1. Preparation of personnel and implement equipment

1) And determining the professional technicians for processing and manufacturing and the planned approach time according to the specific structure, the schedule and the manufactured quantity of the core mold.

2) Various small-sized machines and tools are needed when the core mould is manufactured in a ready mode.

2. Material preparation

1) After the professional technical personnel enter the field, the material supply department makes a material supply plan according to the requirements of the company, and determines the supply location, the quantity, the transportation mode and the field entering time of the required materials.

2) Easily damaged parts such as small-sized machine tools, equipment, power facilities and the like are purchased and stored for standby according to a plan.

3) And (4) according to the approved material supply plan, the purchaser purchases steel plates, rectangular steel, reinforcing steel bars, square timber beams, steel pipes, nuts and other materials into the field in time.

4) The professional technical personnel need to check and accept the materials entering the field, and the qualified materials can be used in the processing and manufacturing of the core mould plate.

3. Technical preparation

Technical preparation is the first important preparation task in the core mold making process. Through technical preparation work, reasonable planning and reasonable arrangement are achieved, the quality and the progress of core mold manufacturing can be guaranteed, and the quality of hollow slab prefabricated products is guaranteed.

1) The professional technical personnel carefully study drawings and other design documents, and are skilled in mastering the design connotation of construction drawings so as to master the structural size and structural characteristics of each part of the hollow slab.

2) According to the design structure characteristics and the geometric dimension of the hollow slab, professionals draw a hollow slab core mold processing and manufacturing planning drawing in time and count the types and the quantity of materials.

3) And reporting a planning chart for processing and manufacturing the core model by the general engineer in time, and adopting the method after the calculation and verification of the structural form, the stress analysis and the geometric dimension of the core model have no errors.

4. Preparation of construction site

The construction site is cleaned according to the characteristics of the machining scale and the site conditions, the site needs to be hardened and leveled, the requirements of laying of small machines and tools, stacking of materials required for manufacturing and production, machining and manufacturing are met, the power transmission line is erected, and machining and production are guaranteed.

5.2.2 mandrel vertical skeleton welding

One of the advancement and characteristics of the construction method is embodied in the structural form of a standing framework for stabilizing the template, the structural form is that the template is supported symmetrically in a ring shaft manner, and standing parts are connected with middle shaft rectangular steel through a loose-leaf structure made of thin steel pipes. Meanwhile, four rows of supporting parts on four longitudinal surfaces of the rectangular steel along the middle shaft can be flexibly folded and supported like a sheet hinge by the traction of longitudinal traction steel bars and the end turn buckle bolts.

1. And (5) manufacturing a middle shaft.

The axis is a square steel pipe (rectangular steel) 120mm x 120mm reaching the national standard, the thickness of the square steel is 5mm, and the length is generally: 2 x [ precast length of hollow slab/2 +50cm (50 cm longer from slab end at each end) ]. The planning and designing process is carried out according to two parts, so that the disassembly and the assembly are convenient, and the construction and the production are convenient.

Constructors cut round steel pipes with the inner diameter of 16mm and the wall thickness of 3mm into small sections with the length of 3cm, the round steel pipes are welded on processed rectangular steel according to planning drawing requirements, the section interval of ring shaft welding is generally 60cm, four ring shafts are welded on each section, and each round steel pipe is welded at the center of each side and used for being used as a hinge structure to connect and erect steel plates (see attached figure 2). In addition, four steel structure hooks are welded at the rectangular steel end of each core mould structure and used for hanging turn buckle bolts, so that the template can be conveniently tensioned and erected and reinforced (see attached figure 3).

2. Symmetrical support component manufacturing

The symmetrical support component is made of steel plates, the material of the symmetrical support component is hot rolled steel plates meeting the national standard, and the thickness of the symmetrical support component is 5 mm. The length of the processing is based on the specific planned length, and the width is generally 9 cm. Two round steel tubes with the length of 2.5cm are welded at one narrow end and close to the long edge along the transverse direction, the distance between the two round steel tubes is 3.5cm, and the round steel tubes of the middle shaft are conveniently connected to form a hinge structure; the other end is welded with a round steel with the length of 9cm and the diameter of 14mm, the round steel is exposed out of the supporting steel sheet by 3cm and is convenient to be inserted into a screw cap on the steel bar pull rod (see attached figure 2). The welded round steel tube and 9cm long steel bars were on one side.

3. Tie rods and other making

The pull rod for pulling up and erecting is round steel with the diameter of 10mm, a screw cap is welded at the interval of every 60cm according to the requirements of planning drawings, and one end of each pull rod is made into a round hole shape, so that the turn buckle can be conveniently hung.

In addition, part of tool steel is processed according to the requirements of a planning drawing, so that the tool steel is convenient to apply during integral assembly.

4. Welding forming of core mold erecting framework

And according to the processed and manufactured components, splicing the components according to a planning design drawing to form a complete framework structure. (see attached FIG. 3)

The steel bar pull rod of the support framework is in a loose state before the core mould is assembled, and at the moment, the support steel plate and the central shaft rectangular steel are close to each other, so that the support framework is convenient to store, move and transport.

5.2.3 core form making

The core mould is generally made in two steps, the first step is to cut and process the steel plate and other materials according to the size and shape required by the planning design drawing, and the second step is to weld and assemble the processed materials. The steel plate is hot-rolled steel plate with thickness of 3mm according with national standard.

1) The steel plate is cut into semi-finished products by special tools according to a planning design drawing, and the semi-finished products are mainly corner templates and supporting rib reinforcing parts of a core mold. The dimension error of all semi-finished products during processing is between 0 and-1 mm.

2) The qualified processed materials are assembled and welded by professional technicians according to the requirements of a planning design drawing, the distribution distance of the welded support ribs is consistent with that of the symmetrical support structure, namely the distance of the welded support ribs is 60cm, and the support ribs on each side template are welded together by steel plate strips, so that the stability of each side template structure is improved.

The sideform length is typically: the hollow slab is prefabricated in length of 2+10 cm.

After welding and forming, correcting each template to reach the standard of a planning drawing, and enabling the geometric dimension allowable deviation of each template to be 0-2 mm. Generally, for an octagonal hollow core slab, one set of core slabs requires 8 corner sideforms to be made.

The side forms are shown in figure 3, a structure diagram of the core mould supporting framework and the side forms.

5.2.4 core Assembly

In the core mold assembling process, constructors mainly do three tasks: firstly, fully preparing; secondly, carefully assembling and reinforcing according to a planning drawing; third, the test structure shape and geometry are carefully calibrated.

1. Ready for work

First, various types of small construction machines are inspected. Such as: a manual trolley for carrying each template and erecting the framework, a manual steel belt binding machine for reinforcing the templates and the like. The small-sized construction machine has good state and meets the construction requirement.

Secondly, 6-8 steel supports for assembling the core mould are made of materials such as channel steel (126mm multiplied by 53mm) and rectangular pipes (30mm multiplied by 30mm), construction personnel assemble the core mould with the aid of the steel supports, and the internal geometric structure of the steel supports is consistent with the external structure of the core mould. Meanwhile, each set of core mold needs 8 pine wood purlin of 10cm multiplied by 10cm, the length is slightly larger than that of each template, the processed section is hexagonal, and the specific structural shape is shown in a structural schematic diagram of a steel bracket and the pine wood purlin in attached figure 4.

The processed square timber purlin is in a hexagonal pattern, and a hexagonal square timber purlin is connected between every two side templates during assembly. Therefore, the angle of the joint of the pine wood purlin and the side template is elaborately processed and manufactured strictly according to the requirements of a drawing, so that the surface of the connected template is compact and flat.

2. Splicing reinforcement

1) And (4) arranging stable steel supports according to the requirements of the assembly planning drawing, and enabling all the steel supports to be on the same plane.

2) The sheet templates and the supporting frameworks are moved to the front of the steel support for assembly by a trolley, and the core mold is assembled by a professional through the assistance of the steel support.

Firstly, two side templates are placed at the bottom of a steel bracket along the length direction of the template, a processed and formed pine tree purlin is placed between the two templates, and the position of the side templates is adjusted.

The steel bar pull rod is pulled through the turn buckle, so that the support steel plate is perpendicular to the middle shaft rectangular steel to form a support framework structure, and then the support framework is placed in the core mold structure which is being assembled.

Finally, other side templates and pine wood purlin are arranged to complete the assembly process.

The adjustment is carried out while the installation is carried out in the assembling process so as to ensure that the structural form and the geometric dimension of the composite material meet the requirements of planning and design. According to the planning requirement, two sections of core moulds are assembled on each plate beam.

3) After assembling, the core mold is firstly tightened by a chain block and then tightened by a binding steel belt through a manual steel belt binding machine and a steel belt fastener so as to ensure the integral stability of the core mold.

4) The calibration mandrel structure dimensions and geometry are checked until specification requirements are met.

3. The core mold formed by assembly is shown in figure 5 as a core mold assembly structure schematic diagram.

4. The section structure schematic diagram of the hollow plate beam core mold such as the round hole, the regular multi-edge hole or the flat multi-edge hole is shown in the attached figure 6.

5.2.5 core die moving and transporting

The core mould reinforced by the self-made small flat plate handlebar is transported to the position near the hollow plate to be poured, if the assembly position is close to the position near the hollow plate to be poured, the core mould can be directly transferred away from the assembly site by a crane during installation without moving, and then the core mould is directly installed by manual cooperation.

5.2.6 core mold seating

The core mould is placed by manually matching with a crane. Before placing, the core mould is tightly wrapped by plastic cloth, the plastic cloth must be uniformly attached to the periphery of the core mould during wrapping, and the phenomena of wrinkling and loosening are avoided, otherwise, the concrete wall thickness of the hollow slab is uneven, or the hollow slab wall generates a plastic cloth interlayer, so that the prefabrication quality of the hollow slab is influenced.

During placement, the core mold is lifted by an 8t crane, a crane operating hand follows the command of construction professionals, the core mold is slowly placed at a designated position, then the core mold is adjusted to a reasonable position required by design by a plurality of professionals, and the core mold can be bound and fixed after being qualified by quality inspection personnel. After the fixing is finished, the accuracy of the placement position of the core mold and the firmness of the core mold are rechecked again, and the next procedure can be carried out only after the confirmation is correct, so that quality accidents do not occur during the prefabrication of the hollow slab.

5.2.7 core mold extraction

When the concrete pouring strength of the prefabricated hollow slab reaches more than 40% of the design strength, the turn buckle can be detached, and each subsection structure of the core mould is extracted.

When the steel bar is drawn out, the turnbuckle is firstly removed, so that the steel bar of the drawing support framework can be loosened, then a constructor slightly pulls the axis rectangular steel outwards by hands, the loose-leaf support steel sheet can be folded, and the support framework can be easily drawn out. After the support framework is extracted, the templates and the wood beams on the upper part, the two sides and the bottom of the core mold are sequentially detached, so that the core mold extraction work is finished.

5.2.8 core mould correction and reassembling

And (4) immediately correcting and maintaining the extracted core die loose part by a professional, and then assembling and forming the core die loose part according to requirements for prefabricating the next hollow slab beam.

5.3 labor organization

According to the structural characteristics of the core mould of the hollow slab and the process requirements of processing and manufacturing, specific construction requirements in the prefabrication process are combined, specific professional operators are reasonably arranged, and about 9 persons are generally arranged in each team. The division is shown in Table 5.3 as the main labor organization table.

TABLE 5.3 Main labor organization Table

6. Materials and apparatus

The main materials in the construction method comprise steel plates, square timber beams, rectangular steel pipes and the like.

The steel plate is required to be a hot rolled steel plate meeting the national standard; the pine wood purlin adopts northeast needle-shaped larch, and the diameter of the pine wood is required to be more than 20cm, and the straight, decay-free and crack-free I wood and other woods are required; the wall thickness of the rectangular steel pipe is not less than 3mm, and the material and the geometric dimension meet the national standard.

The adopted machines and equipment are shown in a table 6, and the main machine and equipment allocation table of the core mold construction method is shown.

Table 6 core mould working method main machine equipment outfit table

Serial number	Implement equipment name	Unit of	Number of	Type and specification	Use of
						1	Electric welding machine	Table (Ref. Table)	2	Within 30kw	Welding templates and other parts
2	Toothless saw	Table (Ref. Table)	1	Diameter of 500cm	Cutting reinforcing bar and steel plate
						3	Woodworking circular sawing machine	Table (Ref. Table)	1	Diameter of 1000cm	Processing wood purlin and the like
4	Small handcart	Table (Ref. Table)	2	Self-made	Transporting tools, forms, or the like
						5	Wheel crane	Table (Ref. Table)	1	8t	Core mould for moving, transporting and hanging
6	Flower basket bolt	An	20	Standard of merit	Erecting core mould
						7	Manual steel belt packaging machine	An	2	SKZ19/16	Bundling core mould
8	Steel belt snap fastener	An	2	C318	Steel belt lock catch
						9	Hand pulling block	An	2		Core mould for holding

7. Quality control

7.1 establishing a sound and effective core mould quality assurance system and a self-checking system.

7.2 establishing a prefabricated hollow slab template team, determining template team leaders and members, determining post responsibilities at all levels, establishing a strict assessment system, and hooking economic benefits and quality.

7.3, the construction design drawing is familiar, the relevant technical and quality requirements in the core mould planning drawing are mastered, and the operation is strictly followed in the manufacturing process.

7.4, strengthening the technical quality management and implementing the bottom-crossing work of various technologies. And (4) meeting the specific construction technology and specification requirements to each member in the template team.

7.5 Special workers need to be certified.

7.6 in core mould preparation and the hollow core slab production process, strict control plays several aspects of decisive influence effect to engineering quality: a skilled operator; good mechanical equipment; high quality engineering materials; a correct construction process; an effective monitoring means; strict detection acceptance criteria.

7.7 allowable deviations of the mandrel process test items are shown in Table 7.6.

TABLE 7.6 actual measurement items of mandrel process

Unit: mm is

8. Safety measures

8.1 in the construction process, the method is strictly executed according to the national construction engineering construction safety management regulations and the relevant regulations of the safety manual of our unit, and always carries out the policy of 'prevention is the main, safety is the first', establishes the safety consciousness of the whole staff, and implements planned and systematized safety production management on the whole construction process.

8.2, implementing the pre-post training system, the special work type must be on duty, and each work type and each post personnel are responsible for coordinating the cooperation construction among the work types.

8.3 deepens the safety education and strengthens the safety awareness. Before the workers go on duty, the workers must carry out work and technique training and safety education.

8.4 signing responsibility of safety production, and making safety production person responsible.

And 8.5, the standardized management of a construction site is enhanced, the standardized consciousness of constructors is enhanced, and the standardized operation quality of the constructors is improved.

8.6 the core mould is moved and transported and hoisted strictly according to the operation rules, the unified command is strengthened, and the action pace is consistent. Construction areas strictly prohibit unrelated people from entering the hazardous area.

8.7 each process is well done with safety technology to meet the end, and the operation can be carried out only after the operation place meets the safety requirement.

8.8 timely providing labor protection, the hand-held electric tool must wear qualified insulating gloves, and all electrical switches are provided with leakage protection devices.

8.9 carry out a weekly large inspection system, carry out a comprehensive inspection on construction machinery, equipment machines and tools, instruments, tools and the like, and find out problems and correct the problems in time.

8.10 the safety responsible person is determined on site, and safety inspection is carried out before and during construction every day.

9. Environmental protection measure

People are responsible for protecting the environment. Therefore, the project department takes various effective measures in the construction process, strictly controls various channels which are easy to cause environmental pollution, and creates good ecological environment for production and living areas.

9.1 seriously executing the environmental protection laws, regulations and regulations established by the national and local governments and strictly carrying out construction production according to the requirements of the superior competent departments.

9.2 strengthening the environmental protection education. Before the operation, all constructors are organized to learn knowledge of ecological environment protection, understand and master various laws, regulations and standards of national and local environment protection, improve propaganda strength and enhance environmental awareness.

And 9.3, standard deployment of a construction site. The construction site is reasonably arranged, the original vegetation is not damaged as much as possible, the phenomena of hacking and cutting are avoided, and the stacking standards of materials and garbage are met. The sanitary work of production and living areas is well done, and meanwhile, flowers, plants and trees are planted around the living areas, so that the living environment is beautified.

9.4 water environment protection measures. Strictly controlling production and domestic wastes and avoiding polluting domestic water sources; the production and domestic sewage must be treated and can be discharged after being detected to meet the discharge standard.

9.5 atmospheric environmental protection measures. When the equipment is selected, low-pollution equipment is selected, water is frequently sprayed to a construction site and a transportation road to keep the ground moist, dust is reduced, volatile products such as gasoline and the like are stored in a sealed manner, and the storage time is controlled as much as possible.

9.6 noise reduction measures. The operation workshop is arranged on engineering equipment used on site, or a temporary sound insulation barrier is built, so that noise transmission is reduced, and the influence of noise on the surrounding environment is reduced.

9.7 solid waste measure. The production, the household garbage and the like are transported to the appointed place to be placed and treated, the messy placement is not abandoned, and the harmful substances are transported to the appointed place of the local environmental protection department to be treated.

9.8 the temporary facilities are cleaned after the project is finished, and the original appearance is recovered.

10. Comprehensive benefit analysis

10.1 the process has the advantages of ingenious design, reasonable design, simple operation and construction quality guarantee.

10.2 in the construction process of the company, the process is well mastered by most of professional technicians and is flexibly applied to the prefabrication of the hollow slab beam.

10.3 because of adopting the advanced construction process, changed the construction process that adopts disposable wooden mold in the past, adopted the pin-connected panel mandrel that can reuse, reduced capital investment and the processing quantity of processing the mandrel, greatly accelerated the construction progress, shortened the time limit for a project, improved economic benefits. The improved core mould of the D standard section hollow slab of the coastal great road in the Yingkou city saves 21 more ten thousand yuan, the Wuji high-speed B13 project in Jiangxi province saves 19 more ten thousand yuan, and the release great bridge in the agricultural reclamation and the Sanjiang province is saved by 9 more ten thousand yuan.

10.4 practice proves that the self-made ring-axis symmetric support type framework has unique conception and reasonable structure, meets the integral stability of the core mould and ensures the construction quality of the hollow slab. Through the change of the structure, each part of the core mould is easy to disassemble and extract, and meanwhile, the core mould is also fast assembled and molded.

10.5 according to the structural superiority and the operating characteristics of the ring axisymmetric supported core mould, each set of core mould can be applied to the prefabrication work of hollow slabs of different models through welding modification, thereby saving a large amount of funds for engineering projects.

10.6 the process is summarized by the company for long-term construction, has simple construction organization, clear construction process and small modification difficulty, and is an economical construction process.