Full-prefabricated assembly type support-free steel bar staggered connection frame and construction method thereof
By using a fully prefabricated, unsupported, staggered rebar connection frame, the problems of temporary support and rebar crossing in prefabricated frame construction are solved, achieving efficient and stable component connection, improving construction efficiency and structural stability, and meeting the requirements of green building.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-04
- Publication Date
- 2026-04-21
AI Technical Summary
Prefabricated frame construction requires a large number of temporary supports, resulting in high material costs, large workspace occupation, and extended construction period. Furthermore, the intersecting reinforcement bars in the joint area make it difficult to place them in place.
The fully prefabricated, unsupported, staggered rebar connection frame is adopted. Through the design of foundation, prefabricated columns, prefabricated main beams, prefabricated secondary beams and prefabricated floor slabs, the post-cast sections and formwork are used to avoid rebar collisions and achieve standardized transportation and on-site connection of components.
The use of temporary supports was reduced, construction costs and safety risks were lowered, construction efficiency was improved, the construction period was shortened, and structural stability was enhanced, which is in line with the concept of green building.
Smart Images
Figure CN121897075A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building construction technology, and in particular to a fully prefabricated, unsupported, staggered rebar connection frame and its construction method. Background Technology
[0002] In the process of promoting prefabricated frame structures, their core advantages (industrialized production and fast construction speed) face a series of specific and interconnected pain points in practice. First, the construction phase still relies heavily on temporary supports: to bear the self-weight of the components and construction loads, each precast beam and slab needs to be equipped with independent vertical temporary supports, which not only results in high material rental costs and occupies work space, but also affects the scheduling of work processes; the erection and dismantling of the support system itself consumes a lot of manpower and time, thus prolonging the construction period. Second, there are obvious spatial conflicts in the joint areas: the protruding steel bars (or sleeves, embedded parts) of the precast beams and columns crisscross in the narrow space, often causing physical interference, making it difficult for the components to be stably positioned. Summary of the Invention
[0003] This invention provides a fully prefabricated, unsupported, staggered rebar connection frame and its construction method, which solves the problem that temporary supports are required during the construction of existing prefabricated frames.
[0004] This invention provides a fully prefabricated, unsupported, staggered-reinforcement connection frame, comprising: a foundation, prefabricated columns, prefabricated main beams, prefabricated secondary beams, and prefabricated floor slabs. A first post-cast section is provided at the upper end of the foundation and the lower end of the prefabricated columns. Positioning bolts of the foundation and the core column of the prefabricated columns are fixed within the first post-cast section, which contains staggered first reinforcing bars. A second post-cast section is provided at the outer side of the upper end of the prefabricated columns and the end of the prefabricated main beams. Steel components of the prefabricated columns and the prefabricated main beams are fixed within the second post-cast section, which also contains staggered second reinforcing bars. The two ends of the prefabricated secondary beams are placed on the prefabricated main beams via crossbeams. The two ends of the prefabricated floor slabs are placed on two prefabricated main beams, and their sides are placed on two prefabricated secondary beams. A third post-cast section is provided between two adjacent prefabricated floor slabs. The upper ends of the prefabricated main beams and the upper ends of the prefabricated columns form the bottom of the post-cast groove, and the two ends of the prefabricated floor slabs form the walls of the post-cast groove.
[0005] Preferably, the upper end of the core column is embedded in the precast column, and the lower end of the core column is fixed with a base plate, the base plate being provided with positioning holes adapted to the positioning screw.
[0006] Preferably, the core column includes two vertical plates arranged in a cross shape. The lower end of the vertical plate is fixed to the base plate, and the upper end of the vertical plate is embedded in the precast column. The vertical plate is provided with connecting holes, and the two connecting holes are connected.
[0007] Preferably, a rib is fixed between the two vertical plates.
[0008] Preferably, the steel component is an I-beam, and the I-beam of the precast main beam is placed on the I-beam of the precast column, and the two I-beams are fixed by welding or bolts.
[0009] Preferably, there is a gap between the front end of the I-beam of the precast main beam and the precast column, and there is a gap between the front end of the I-beam of the precast column and the precast main beam.
[0010] Preferably, the upper surface of the precast main beam formed of concrete is flush with the upper surface of the precast column formed of concrete, and the upper surface of the precast secondary beam formed of concrete is flush with the upper surface of the precast main beam formed of concrete.
[0011] Preferably, a pad is fixed to the bottom of the ox-bearing plate, and there are two ox-bearing plates at the ends of the precast secondary beam.
[0012] Preferably, the precast floor slab is provided with a third reinforcing bar in the third post-cast section, and the precast secondary beam is provided with a fourth reinforcing bar in the third post-cast section. The third reinforcing bars of the two precast floor slabs are staggered, and the third and fourth reinforcing bars are staggered.
[0013] This invention provides a construction method for a fully prefabricated, unsupported, staggered-reinforcement frame as described above, comprising the following steps: S1: The foundation is poured on site, with a positioning screw and the first reinforcing bar reserved above the foundation; S2: Hoist the precast column above the foundation, pass the positioning screw through the positioning hole on the bottom plate of the precast column, tighten the nut on the positioning screw to fix the core column of the precast column on the foundation; install stirrups and tie bars in the first post-cast section, and then install the formwork and pour concrete to connect the precast column and the foundation into a whole. S3: After all precast columns are installed, hoist the precast main beam, place the steel components of the precast main beam on the steel components of the precast column, and fix the two steel components in the second post-cast section together by welding or bolts; install stirrups in the second post-cast section, and then install the formwork and pour concrete to connect the precast column and the precast main beam into a whole. S4: After all precast main beams are installed, hoist the precast secondary beams and place the end plates of the precast secondary beams on the two precast main beams respectively; after all precast secondary beams are installed, hoist the precast floor slabs and place the end plates of the precast floor slabs on the two precast main beams respectively, and place the two side plates of the precast floor slabs on the two precast secondary beams respectively. Pour concrete in the third post-cast section to connect the precast floor slabs and precast secondary beams into a whole.
[0014] Compared with existing technologies, this invention divides the frame into five components: foundation, precast columns, precast main beams, precast secondary beams, and precast floor slabs. These five components are connected together by bolts, welding, or by resting, simplifying the process and speeding up the operation. It eliminates the need for steel reinforcement connections, avoiding issues such as steel reinforcement collisions and difficulties in component placement. First, the cast-in-place foundation provides support for the precast columns. Then, the components are connected together via post-cast sections to form a unified structure, supporting the next component, thus achieving support-free construction. The precast columns, main beams, secondary beams, and floor slabs are columnar or slab-shaped components, improving the standardization of components and facilitating transportation. Secondly, during concrete pouring, only a small number of formwork templates are needed for the first, second, and third post-cast sections and the pouring trench, effectively reducing the workload. Thirdly, the five components—foundation, precast columns, main beams, secondary beams, and floor slabs—are connected as a whole, resulting in good structural stability of the frame. This invention significantly reduces construction costs and safety risks, improves efficiency, shortens construction period, and reduces carbon emissions, thus practicing green concepts; it also helps the development of industrialized building, expands its application scenarios, and provides strong support for the high-quality development of the industry. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the basic structure of the present invention; Figure 3 This is a schematic diagram of the core post structure of the present invention; Figure 4 This is a schematic diagram of the structure of the precast column of the present invention; Figure 5 This is a schematic diagram of the prefabricated secondary beam of the present invention; Figure 6 This is a schematic diagram of the prefabricated main beam of the present invention; Figure 7 This is a schematic diagram of the prefabricated floor slab of the present invention; Figure 8 This is a schematic diagram of the structure for fixing the core post and the positioning screw according to the present invention; Figure 9 This is a schematic diagram of the structure for installing stirrups in the first post-cast section of the present invention; Figure 10 This is a schematic diagram of the structure after the first post-cast section of the present invention has been poured with concrete; Figure 11 This is a schematic diagram of the structure for fixing the precast main beam and precast column according to the present invention; Figure 12 This is a schematic diagram of the structure of the present invention, showing the precast secondary beam placed on the precast main beam; Figure 13 This is a schematic diagram showing the placement of the two steel components of the present invention.
[0017] Figure label: 1. Foundation, 2. Precast column, 3. Precast main beam, 4. Precast secondary beam, 5. Precast floor slab, 100. First post-cast section, 200. Second post-cast section, 300. Third post-cast section, 400. Post-cast groove, 11. Positioning bolt, 12. First reinforcing bar, 21. Core column, 22. Steel component, 23. Second reinforcing bar, 211. Base plate, 2111. Positioning hole, 212. Vertical plate, 2121. Connecting hole, 213. Rib plate, 31. Fifth reinforcing bar, 41. Bracket plate, 42. Pad plate, 43. Fourth reinforcing bar, 51. Third reinforcing bar, 52. Sixth reinforcing bar. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0019] See attached document Figure 1 This embodiment provides a fully prefabricated, unsupported, staggered-reinforcement connection frame, including: a foundation 1, prefabricated columns 2, prefabricated main beams 3, prefabricated secondary beams 4, and prefabricated floor slabs 5. A first post-cast section 100 is provided at the upper end of the foundation 1 and the lower end of the prefabricated columns 2, as shown in the attached diagram. Figure 8 The positioning screw 11 of foundation 1 and the core column 21 of precast column 2 are fixed in the first post-cast section 100, and the first post-cast section 100 is provided with staggered first reinforcing bars 12; the outer side of the upper end of precast column 2 and the end of precast main beam 3 are provided with a second post-cast section 200, as shown in the attached figure. Figure 11The steel components 22 of the precast column 2 and the steel components 22 of the precast main beam 3 are fixed in the second post-cast section 200, and the second post-cast section 200 is provided with staggered second reinforcing bars 23; the two ends of the precast secondary beam 4 are placed on the precast main beam 3 through the crossbeam 41, the two ends of the precast floor slab 5 are respectively placed on the two precast main beams 3, and the two sides are respectively placed on the two precast secondary beams 4, and a third post-cast section 300 is provided between two adjacent precast floor slabs 5. The upper end of the precast main beam 3 and the upper end of the precast column 2 are the bottom of the post-cast groove 400, and the two ends of the precast floor slab 5 are the groove walls of the post-cast groove 400. In this invention, the frame is divided into five components: foundation 1, precast column 2, precast main beam 3, precast secondary beam 4 and precast floor slab 5. Only the foundation 1 is cast on site, and the other four components are precast in the factory and then transported to the site, reducing the amount of on-site casting. Furthermore, the precast columns 2, precast main beams 3, precast secondary beams 4, and precast floor slabs 5 are columnar or slab-shaped components, facilitating transportation. The precast columns 2 are fixed to the foundation 1 via positioning bolts 11 and core columns 21, receiving support from the foundation 1 without the need for temporary supports. Concrete is poured within the first post-cast section 100 to connect the precast columns 2 and the foundation 1 as a single unit. When the precast main beam 3 is fixed to the precast columns 2 via steel components 22, it receives support from the precast columns 2, eliminating the need for temporary supports. Concrete is poured within the second post-cast section 200 to connect the precast main beams 3 and precast columns 2 as a single unit. When the precast secondary beams 4 are placed on the precast main beams 3 via bracing 41, they receive support from the precast main beams 3. When the precast floor slabs 5 are placed on the precast main beams 3 and precast secondary beams 4, they receive support from the precast main beams 3 and precast secondary beams 4. Concrete is poured within the third post-cast section 300 to connect the precast secondary beams 4 and precast floor slabs 5 as a single unit. Part of the precast floor slab 5 is placed on the precast main beam 3, forming a stepped shape. When the precast floor slab 5 is laid on the precast main beam 3 or precast wall panels are installed to form another wall of the post-casting groove 400, concrete is poured in the post-casting groove 400 to connect the precast main beam 3 and the precast floor slab 5 into one unit. Through this structural design, the precast column 2 is first supported by the foundation 1, and then the two are connected together by the first post-casting section 100 to serve as the support for the next component. Then, the two are connected together again by the post-casting section to serve as the support for the next component, and so on, connecting the five components of foundation 1, precast column 2, precast main beam 3, precast secondary beam 4, and precast floor slab 5 into a whole, resulting in good structural stability of the frame. Secondly, when pouring concrete, only a small amount of formwork is needed for the first post-casting section 100, the second post-casting section 200, the third post-casting section 300, and the post-casting groove 400, which can effectively reduce the amount of formwork. The components can provide support for the formwork, which can effectively reduce the difficulty of formwork.
[0020] One embodiment of the core post 21: Refer to the appendix Figure 3The upper end of the core column 21 is embedded in the concrete of the precast column 2, and the lower end of the core column 21 is fixed with a base plate 211. The base plate 211 has positioning holes 2111 that are compatible with the positioning screws 11. The core column 21 is located at the center of the precast column 2, with a certain distance from all four sides of the precast column 2. The base plate 211 is in contact with the foundation 1, which can expand the support area. Specifically, a connecting plate is fixed to the upper end of the core column 21, and the connecting plate is embedded in the precast column 2.
[0021] In another embodiment of the present invention: the core column 21 includes two vertical plates 212, which are arranged in a cross shape. The lower end of the vertical plate 212 is fixed to the base plate 211, and the upper end of the vertical plate 212 is embedded in the concrete of the precast column 2. The vertical plate 212 is provided with a connecting hole 2121, and the two connecting holes 2121 are connected. The connecting hole 2121 facilitates the passage of the tie rod, and facilitates the formation of an interlocking relationship with the concrete when the concrete is poured in the first post-cast section 100.
[0022] As another embodiment of the present invention: a rib plate 213 is fixed between the two vertical plates 212, and the connection hole 2121 reduces the structural strength of the core column 21, while the rib plate 213 can effectively ensure the structural strength of the core column 21.
[0023] Specifically, the core column 21 is embedded in the concrete of the precast column 2 with a length of 400~500mm.
[0024] As another embodiment of the present invention: refer to the appendix Figure 4 Steel component 22 is an I-beam. One end of one I-beam is located within the second post-cast section 200, and the other end is embedded in the concrete of the precast main beam 3. The other I-beam has one end located within the second post-cast section 200, and the other end is embedded in the concrete of the precast column 2. The I-beams of the precast main beam 3 are placed on the I-beams of the precast column 2. The two I-beams are fixed by welding or bolts, a simple fixing method. When fixed by bolts, the I-beams have mounting holes for bolts to pass through.
[0025] As another embodiment of the present invention: refer to the appendix Figure 13 There is a gap between the front end of the I-beam of the precast main beam 3 and the precast column 2, and there is a gap between the front end of the I-beam of the precast column 2 and the precast main beam 3.
[0026] As another embodiment of the present invention: refer to the appendix Figure 12 The upper surface of the precast main beam 3, formed by concrete, is flush with the upper surface of the precast column 2, formed by concrete. The upper surface of the precast secondary beam 4, formed by concrete, is flush with the upper surface of the precast main beam 3, formed by concrete. This structural design facilitates the installation of precast floor slabs 5.
[0027] As another embodiment of the present invention: refer to the appendix Figure 5 The bottom of the ox-bearing plate 41 is fixed with a pad 42. There are two ox-bearing plates 41 at the ends of the precast secondary beam 4. Through this structural design, the bearing area can be expanded.
[0028] As another embodiment of the present invention: refer to the appendix Figure 7 The precast floor slab 5 has a third reinforcing bar 51 within the third post-cast section 300, and the precast secondary beam 4 has a fourth reinforcing bar 43 within the third post-cast section 300. The third reinforcing bars 51 of the two precast floor slabs 5 are staggered within the third post-cast section 300, and the third reinforcing bars 51 and the fourth reinforcing bars 43 are also staggered within the third post-cast section 300. The precast secondary beam 4 is placed on the precast main beam 3 via a support plate 41. It is not fixed to the precast main beam 3. Through the reinforcement structure design, the connection between the precast floor slab 5 and the precast secondary beam 4 is made more secure after the concrete is poured in the third post-cast section 300.
[0029] As another embodiment of the present invention: refer to the appendix Figure 6 The upper end of the precast main beam 3 is provided with a fifth reinforcing bar 31, and multiple sixth reinforcing bars 52 are fixed on the side of the precast floor slab 5 facing the fifth reinforcing bar 31. After pouring concrete in the post-casting groove 400, the connection between the precast floor slab 5 and the precast main beam is made more secure.
[0030] This invention provides a construction method for a fully prefabricated, unsupported, staggered-reinforcement frame as described above, comprising the following steps: S1: Refer to Appendix Figure 1 Foundation 1 is poured on site. Positioning screws 11 and first reinforcing bars 12 are reserved above foundation 1. When pouring foundation 1, the pre-embedded positioning screws 11 are positioned using screw positioning molds, and the position of the first reinforcing bars 12 is checked at the same time. Foundation 1 is poured after the position is confirmed to be correct. S2: Measure and lay out the precast column 2 to determine its position, correct the column reinforcement position, level with steel shims, and hoist the precast column 2 above the foundation 1 using slings and lifting equipment. The positioning screw 11 passes through the positioning hole 2111 on the base plate 211 of the precast column 2. The base plate 211 rests horizontally on the top surface of the foundation 1. After verifying the elevation and position, tighten the nut on the positioning screw 11. Refer to the attached document. Figure 8 This fixes the core column 21 of the precast column 2 to the foundation 1. The first reinforcing bar 12 of the precast column 2 is staggered with the first reinforcing bar 12 on the foundation 1. The installation of the other precast columns 2 is completed according to the above steps. (See attached diagram.) Figure 9 Supported by foundation 1, stirrups and tie bars are installed in the first post-cast section 100, as shown in the attached diagram. Figure 10 Install the formwork and pour concrete to connect the precast column 2 and foundation 1 into a whole; S3: After all precast columns 2 are installed, mark the positioning axis and the positioning control line of the precast main beam 3. Mark the lines on the side of the precast column 2 for positioning control. Verify the elevation of the pre-embedded steel components 22 on the top side of the precast column 2, and level the elevation using shims. Hoist the precast main beam 3, placing the steel components 22 of the precast main beam 3 onto the steel components 22 of the precast column 2. After verification, fix the two steel components 22 within the second post-cast section 200 together by welding or bolts, referring to the attached diagram. Figure 11 This fixes the precast main beam 3 to the precast column 2. The second reinforcing bars 23 of the precast column 2 and the second reinforcing bars 23 of the precast main beam 3 are staggered. The installation of other precast main beams 3 is completed according to the above steps. The precast column 2 provides support. Stirrups are installed in the second post-cast section 200. Then, the formwork is installed and concrete is poured to connect the precast column 2 and the precast main beam 3 into a whole. S4: After all precast main beams 3 are installed, measure and lay out the lines, and verify the top surface elevation of the support plate 41 of the precast secondary beams 4 on the precast main beams 3. After verification, hoist the precast secondary beams 4, placing the support plates 41 at both ends of the precast secondary beams 4 on the two precast main beams 3 respectively. After all precast secondary beams 4 are installed, measure and lay out the lines, hoist the precast floor slabs 5, placing the two ends of the precast floor slabs 5 on the two precast main beams 3 respectively, and placing the two side plates of the precast floor slabs 5 on the two precast secondary beams 4 respectively. Refer to the attached diagram. Figure 12 At both ends of the third post-cast section 300, formwork is installed and concrete is poured to connect the precast floor slab 5 and the precast secondary beam 4 into a whole.
[0031] S5: Hoist the precast floor slab 5 or precast wall panel to form the wall of the post-cast trench 400, refer to the attached document. Figure 1 Concrete is poured into the post-cast trench 400 to connect the precast main beam 3 and the precast floor slab 5 into one unit.
[0032] High-strength steel fiber reinforced concrete is poured in the first post-pouring section 100, the second post-pouring section 200, the third post-pouring section 300, and the post-pouring trough 400.
[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A fully prefabricated, unsupported, staggered-reinforcement connection frame, characterized in that, include: The system comprises a foundation, precast columns, precast main beams, precast secondary beams, and precast floor slabs. A first post-cast section is provided at the upper end of the foundation and the lower end of the precast columns. Positioning bolts of the foundation and the core column of the precast columns are fixed within the first post-cast section, which contains staggered first reinforcing bars. A second post-cast section is provided at the outer side of the upper end of the precast columns and the end of the precast main beams. Steel components of the precast columns and the precast main beams are fixed within the second post-cast section, which also contains staggered second reinforcing bars. The two ends of the precast secondary beams are placed on the precast main beams via slabs. The two ends of the precast floor slabs are placed on two precast main beams, and their sides are placed on two precast secondary beams. A third post-cast section is provided between two adjacent precast floor slabs. The upper ends of the precast main beams and the upper ends of the precast columns form the bottom of the post-cast groove, and the two ends of the precast floor slabs form the walls of the post-cast groove.
2. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 1, characterized in that, The upper end of the core column is embedded in the precast column, and the lower end of the core column is fixed with a base plate. The base plate is provided with positioning holes that are compatible with the positioning screw.
3. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 2, characterized in that, The core column includes two vertical plates arranged in a cross shape. The lower end of the vertical plate is fixed to the base plate, and the upper end of the vertical plate is embedded in the precast column. The vertical plate is provided with connecting holes, and the two connecting holes are connected.
4. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 3, characterized in that, A rib is fixed between the two vertical plates.
5. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 4, characterized in that, The steel component is an I-beam, and the I-beam of the precast main beam is placed on the I-beam of the precast column. The two I-beams are fixed by welding or bolts.
6. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 5, characterized in that, There is a gap between the front end of the I-beam of the precast main beam and the precast column, and there is a gap between the front end of the I-beam of the precast column and the precast main beam.
7. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 6, characterized in that, The upper surface of the precast main beam formed of concrete is flush with the upper surface of the precast column formed of concrete, and the upper surface of the precast secondary beam formed of concrete is flush with the upper surface of the precast main beam formed of concrete.
8. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 7, characterized in that, The bottom of the ox-bearing plate is fixed with a pad, and there are two ox-bearing plates at the ends of the precast secondary beam.
9. The fully prefabricated, unsupported, staggered rebar connection frame according to claim 8, characterized in that, The precast floor slab has a third reinforcing bar in the third post-cast section, and the precast secondary beam has a fourth reinforcing bar in the third post-cast section. The third reinforcing bars of the two precast floor slabs are staggered, and the third and fourth reinforcing bars are staggered.
10. A construction method comprising the fully prefabricated, unsupported, staggered-reinforcement frame according to any one of claims 1-9, characterized in that, Includes the following steps: S1: The foundation is poured on site, with a positioning screw and the first reinforcing bar reserved above the foundation; S2: Hoist the precast column above the foundation, pass the positioning screw through the positioning hole on the bottom plate of the precast column, tighten the nut on the positioning screw to fix the core column of the precast column on the foundation; install stirrups and tie bars in the first post-cast section, and then install the formwork and pour concrete to connect the precast column and the foundation into a whole. S3: After all precast columns are installed, hoist the precast main beam, place the steel components of the precast main beam on the steel components of the precast column, and fix the two steel components in the second post-cast section together by welding or bolts; install stirrups in the second post-cast section, and then install the formwork and pour concrete to connect the precast column and the precast main beam into a whole. S4: After all precast main beams are installed, hoist the precast secondary beams and place the end plates of the precast secondary beams on the two precast main beams respectively; after all precast secondary beams are installed, hoist the precast floor slabs and place the end plates of the precast floor slabs on the two precast main beams respectively, and place the two side plates of the precast floor slabs on the two precast secondary beams respectively. Pour concrete in the third post-cast section to connect the precast floor slabs and precast secondary beams into a whole.