Prefabricated concrete frame structure system and construction method thereof

Abstract

The application relates to the technical field of building structures, and provides a fabricated concrete frame structure system and a construction method thereof, the structure system comprising: a prefabricated column, the four corners of the cross section of which are provided with column longitudinal steel bars; a prefabricated node core area, the outer sides of which are provided with horizontally extended lap steel bars; the four corners of the prefabricated node core area are provided with through holes; a prefabricated beam, which adopts a U-shaped membrane shell, the top of the U-shaped membrane shell is open to form an open cavity; a prefabricated composite floor slab, which comprises a prefabricated concrete bottom plate and a post-cast concrete area, the prefabricated concrete bottom plate is provided with a plate end extending steel bar; the post-cast concrete area is provided with an upper layer of steel mesh; in the vertical direction, the column longitudinal steel bars of the lower layer of prefabricated columns pass through the through holes, penetrate into the first through holes of the upper layer of prefabricated columns, and are lapped with the column longitudinal steel bars of the upper layer of prefabricated columns; in the horizontal direction, beam longitudinal steel bars are lapped with the lap steel bars; and in the floor direction, the prefabricated composite floor slab is laid on the prefabricated beam, and the plate end extending steel bar is lapped with the upper layer of steel mesh.

Description

Technical Field

[0001] This invention relates to the field of building structure technology, and in particular to a prefabricated concrete frame structure system and its construction method. Background Technology

[0002] Prefabricated concrete frame structures are an important form of building industrialization. In existing technologies, the connection methods for prefabricated concrete frame structures mainly include sleeve grouting connection and grout anchor connection.

[0003] However, existing technologies for connecting concrete frame structures involve isolated connections with high precision requirements. Sleeve connections require millimeter-level precision in rebar insertion, making on-site installation difficult; even slight deviations can prevent installation. Furthermore, the sleeves and specialized grouting materials are expensive, increasing project costs. Additionally, the joint area has dense rebar reinforcement.

[0004] Therefore, how to provide a prefabricated concrete frame structure and its construction method that allows for a large tolerance range is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a prefabricated concrete frame structure system and its construction method to solve the problem of difficult on-site installation in the prior art, and to achieve large tolerance assembly in three-dimensional space and overall coordinated stress.

[0006] This invention provides a prefabricated concrete frame structure system, comprising: a precast column, with longitudinal steel bars at the four corners of the cross section; a first through hole at each of the four corners of the precast column along its length, the first through hole being used for the lap splicing of the longitudinal steel bars of the upper and lower precast columns; and an inwardly bent section at the end of the longitudinal steel bar extending from the top side of the precast column. The core area of ​​the precast node is equipped with horizontally extending lapped steel bars on the outer side; through holes are provided at the four corners of the core area of ​​the precast node. The precast beam uses a U-shaped membrane shell, with the top of the U-shaped membrane shell open to form an open cavity; the open cavity is provided with longitudinal reinforcement bars of the beam arranged along its length. Precast composite floor slabs include a precast concrete base slab and a post-cast concrete zone. The precast concrete base slab has a steel mesh and has steel bars extending from the slab ends. The post-cast concrete zone has an upper steel mesh. Vertically, the longitudinal reinforcement bars of the lower precast column pass through the through hole, extend into the first through hole of the upper precast column, and lap with the longitudinal reinforcement bars of the upper precast column; horizontally, the longitudinal reinforcement bars of the beam lap with the lapped reinforcement bars; in the floor slab direction, the precast composite floor slab is laid on the precast beam, and the slab end protruding reinforcement bars lap with the upper reinforcement mesh.

[0007] According to the prefabricated concrete frame structure system provided by the present invention, the entire length of the precast beam is a U-shaped membrane shell, the longitudinal reinforcement of the beam is flush with the end of the precast beam, and U-shaped stirrups are pre-embedded at intervals along the length of the U-shaped membrane shell; the U-shaped stirrups are pre-embedded inside the U-shaped membrane shell with the opening facing upward, the bottom and sides are poured into the concrete of the U-shaped membrane shell, the top opening is exposed, and the post-poured concrete area is filled into the open cavity.

[0008] According to the prefabricated concrete frame structure system provided by the present invention, a second through hole penetrating the length of the prefabricated column is provided in the middle of the prefabricated column.

[0009] According to the prefabricated concrete frame structure system provided by the present invention, the first through hole is formed by corrugated pipe, the inner wall of the corrugated pipe has a rough surface, and the outer periphery of the corrugated pipe is provided with spiral stirrups.

[0010] According to the present invention, a prefabricated concrete frame structure system is provided in which the through hole is formed by a sleeve; the inner wall of the sleeve is provided with stiffening ribs or studs.

[0011] According to the prefabricated concrete frame structure system provided by the present invention, the inner wall of the U-shaped membrane shell is set as a rough surface.

[0012] According to the prefabricated concrete frame structure system provided by the present invention, it further includes: The sealing stirrup connects to the open end of the U-shaped stirrup to form a closed stirrup.

[0013] According to the prefabricated concrete frame structure system provided by the present invention, the surface of the prefabricated bottom plate of the prefabricated composite floor slab is roughened or indented.

[0014] According to the prefabricated concrete frame structure system provided by the present invention, multiple longitudinal steel bars for columns are provided in the first through hole.

[0015] This invention also provides a construction method for a prefabricated concrete frame structure system, comprising: S1. Factory Prefabrication: Prefabricate precast columns, precast beams, precast composite floor slabs, and precast core areas of nodes according to design drawings; when prefabricating precast columns, first through holes are reserved at the four corners and second through holes are reserved at the center. Spiral stirrups are set in the lap area of ​​the longitudinal reinforcement around the first through holes. The part of the longitudinal reinforcement extending beyond the top of the column is pre-bent to form an inwardly bent section; when prefabricating the core area of ​​nodes, reinforcing sleeves are pre-embedded in the four corner holes, closed stirrups are tied, and lapped reinforcement is reserved; when prefabricating beams, the entire beam adopts a U-shaped membrane shell form, the longitudinal reinforcement of the beam is pre-embedded, and U-shaped stirrups are pre-embedded at intervals along the length of the beam inside the U-shaped membrane shell; when prefabricating composite floor slabs, the steel mesh inside the slab is tied, and protruding reinforcement is reserved at the end of the slab. S2. Installation of lower-level columns: Hoist the lower-level precast columns into place, and temporarily fix them after correcting their verticality and position; S3. Installation of the node core area: The prefabricated node core area is hoisted into place so that the longitudinal reinforcement of the lower column passes through the four corner through holes of the node core area. S4. Beam hoisting: Hoist the precast beam into position so that the open cavity of the U-shaped membrane shell at the beam end fits onto the horizontally extended lapped steel bars in the core area of ​​the node. The horizontally extended lapped steel bars extend into the open cavity of the membrane shell, forming a staggered lapped relationship with the longitudinal steel bars of the beam. S5. Beam end stirrup closure: Tie a sealing stirrup to the top of the beam end. The sealing stirrup is connected to the open end of the U-shaped stirrup pre-embedded inside the U-shaped membrane shell to form a closed stirrup together. S6. Floor slab laying: The precast composite floor slab is laid on the precast beam, and the steel bars extending from the end of the slab are tied and lapped with the continuous steel bars in the post-cast area at the top of the beam. S7. Binding the upper layer of steel mesh: Binding the upper layer of steel mesh above the precast composite floor slab; S8. Post-pouring construction: Concrete is poured into the four corner through holes of the core area of ​​the node, the first through hole of the four corner of the column, the open cavity of the U-shaped membrane shell, the post-pouring area of ​​the beam top and the post-pouring layer of the floor slab to form the overall structure of this layer. S9. Upper column hoisting: After the concrete of this layer reaches the required strength, hoist the upper precast column and guide it through the core area of ​​the node by using the inward bending section of the longitudinal reinforcement at the end of the lower column, and into the first through hole at the four corners of the bottom of the upper column. Repeat S2 to S8 to carry out the construction of the next layer.

[0016] This invention provides a prefabricated concrete frame structure system and its construction method. Vertically, the longitudinal reinforcement of the lower-level precast columns passes through through holes, extending into the first through hole of the upper-level precast column and lapping with the longitudinal reinforcement of the upper-level precast column. Horizontally, the longitudinal reinforcement of the beams laps with the lapped reinforcement. In the floor slab direction, precast composite floor slabs are laid on precast beams, with the slab end reinforcement lapping with the upper-level steel mesh. That is, tolerance design is adopted in the vertical, horizontal, and floor slab directions, forming a three-dimensional, large-tolerance connection network. Vertically, centimeter-level vertical tolerance is achieved by utilizing the guiding fit between the inwardly bent sections of the column reinforcement and the first through holes at the four corners of the upper-level precast column, as well as the tolerance space of the large-diameter through holes in the core area of ​​the nodes. Horizontally, the open cavity body accommodates the lapped reinforcement in the core area of ​​the nodes, lapping with the longitudinal reinforcement of the beams, eliminating the need for precise alignment. In the floor slab direction, the slab end reinforcement laps with the upper-level steel mesh, allowing for a certain degree of deviation. The omnidirectional tolerance design significantly reduces the construction difficulty of the entire frame structure, relaxing the traditional "millimeter-level alignment" requirement to "centimeter-level tolerance range".

[0017] This invention establishes clear vertical, horizontal, and floor-slab force transmission paths, with the three-dimensional force flows converging at the core node area to form a complete spatial force transmission network. Vertical force flows are transmitted through the through-holes in the core node area. Horizontal force flows converge into the core node area after the lapped reinforcing bars in the core node area overlap with the longitudinal reinforcing bars of the beam within the U-shaped membrane. Floor-slab force flows are jointly stressed by the precast base slab reinforcement mesh and the post-cast layer reinforcement mesh, and then transmitted through the protruding reinforcing bars at the slab ends to the post-cast concrete area at the top of the beam, ultimately also converging into the core node area. The force transmission in each direction is independent and works collaboratively, with a simple and clear force transmission path. The core node area, as the force flow convergence hub, experiences reasonable stress distribution.

[0018] Precast columns are reinforced with spiral stirrups in the lap joint area to create strong constraints, and reinforced sleeves are built into the core area of ​​the nodes to form composite nodes. Precast beams achieve ductile failure mechanism through staggered lap joints within a U-shaped membrane shell. The core areas of precast columns and precast nodes have higher load-bearing capacity and ductility, and ductile failure is achieved through lap joints at the beam ends, fully realizing the seismic design principle of "strong column-weak beam, strong node-weak component".

[0019] The U-shaped stirrups are pre-embedded inside the U-shaped membrane shell, with the opening facing upwards. The bottom and sides are already cast in concrete, so they will not interfere with the beam hoisting. After the beam is hoisted into place, only simple sealing stirrups need to be tied at the top and connected to the open end of the U-shaped stirrups to form a complete closed stirrup. The purpose of this design is to simplify the complex work of tying the beam end stirrups to a top sealing operation, reducing the difficulty of on-site construction, while ensuring the integrity and restraint effect of the closed stirrups at the beam ends.

[0020] Precast columns, precast beams composed of U-shaped membrane shells, precast joint core areas, and precast composite floor slabs are all prefabricated in the factory. On-site work only requires hoisting, tying a small amount of additional reinforcement, and pouring concrete for the joint cavities, beam end membrane shells, and post-cast floor slab layers. The open cavity of the U-shaped membrane shell directly serves as the formwork for the post-cast concrete after the beams are hoisted, eliminating the need for additional formwork. This results in rapid construction, a clean site, and aligns with the development trend of industrialized construction. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is an overall schematic diagram of the connection node of the prefabricated concrete frame in an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 Exploded view.

[0024] Figure 3 This is a schematic diagram of the assembly of the node area with beams, slabs and columns in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the structure of the precast column in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the core area of ​​the prefabricated node in an embodiment of the present invention; Figure 6 This is a schematic diagram of the precast beam in an embodiment of the present invention.

[0026] Figure label: 1. Precast column; 2. Precast beam; 3. Precast node core area; 4. Precast composite floor slab; 5. Longitudinal reinforcement of column; 6. First through hole; 7. Second through hole; 8. U-shaped stirrup; 9. Lap reinforcement; 10. Slab end extension reinforcement; 11. Upper layer reinforcement mesh; 12. Sealing stirrup; 13. Post-cast concrete area; 14. Spiral stirrup; 15. Inward bending section; 16. Reinforcing sleeve; 17. U-shaped membrane shell. Detailed Implementation

[0027] 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.

[0028] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] The following is combined Figures 1 to 6 The prefabricated concrete frame structure system provided in the embodiments of the present invention includes prefabricated columns 1, prefabricated node core area 3, prefabricated beams 2, and prefabricated composite floor slabs.

[0030] The precast column 1 has longitudinal steel bars 5 at its four corners. The precast column 1 also has first through holes 6 at its four corners along its length. The first through holes 6 are used for the lap joint of the longitudinal steel bars 5 of the upper and lower precast columns 1. The ends of the longitudinal steel bars 5 extending from the top side of the precast column 1 are provided with inward bending sections 15. The inward bending sections 15 guide the longitudinal steel bars 5 into the first through holes 6 at the four corners of the upper precast column 1, forming a staggered lap joint with the longitudinal steel bars 5 of the upper column within the constraint zone of the spiral stirrups 14.

[0031] The outer sides of the core area 3 of the precast node are provided with horizontally extending lapped steel bars 9; through holes are provided at the four corners of the core area 3 of the precast node.

[0032] Precast beam 2 adopts a U-shaped membrane shell 17, with an open top forming an open cavity; longitudinal reinforcement bars are installed on the open cavity along its length. The entire length of precast beam 2 uses a U-shaped membrane shell 17, significantly reducing its self-weight compared to a solid beam; the floor slab is a composite slab, consisting of precast thin slabs and a post-cast layer. The overall structural self-weight is significantly reduced, lowering transportation and hoisting costs.

[0033] The precast composite floor slab includes a precast concrete base slab and a post-cast concrete zone 13. The precast concrete base slab is equipped with a steel mesh and has steel bars 10 extending from the slab ends. The post-cast concrete zone 13 is equipped with an upper steel mesh 11. The upper steel mesh 11 set in the post-cast concrete layer and the steel mesh built into the concrete base slab together form a two-way reinforcement and are integrally cast with the top post-cast zone of the precast beam 2.

[0034] Vertically, the longitudinal steel bars 5 of the lower precast column 1 pass through the through hole and extend into the first through hole 6 of the upper precast column 1, and overlap with the longitudinal steel bars 5 of the upper precast column 1; horizontally, the longitudinal steel bars of the beam overlap with the lapped steel bars 9; in the floor slab direction, the precast composite floor slab is laid on the precast beam 2, and the steel bars 10 extending from the slab end overlap with the upper steel mesh 11.

[0035] This invention employs tolerance design in the vertical, horizontal, and floor slab directions, forming a large-tolerance connection network in three-dimensional space. Vertically, it utilizes the guiding fit between the inwardly bent section 15 of the column reinforcement and the first through-hole 6 at the four corners of the upper column, as well as the tolerance space of the large-diameter through-hole in the core area of ​​the node, to achieve centimeter-level vertical tolerance. Horizontally, it utilizes the open cavity of the U-shaped membrane shell 17 to accommodate the lap joint of the node's reserved reinforcement and the beam reinforcement, eliminating the need for precise alignment. In the floor slab direction, it utilizes the lap joint of the slab-end protruding reinforcement with the beam top reinforcement, allowing for a certain degree of deviation. This omnidirectional tolerance design significantly reduces the construction difficulty of the entire frame structure, relaxing the traditional "millimeter-level alignment" requirement to a "centimeter-level tolerance range."

[0036] In a feasible embodiment of the present invention, the entire length of the precast beam 2 is a U-shaped membrane shell 17, the longitudinal reinforcement of the beam is flush with the end of the precast beam 2, and U-shaped stirrups 8 are embedded at intervals along the length of the U-shaped membrane shell 17. The U-shaped stirrups 8 are embedded inside the U-shaped membrane shell 17 with their openings facing upwards, and the bottom and sides are poured into the concrete of the U-shaped membrane shell 17, with the top opening exposed. The post-poured concrete area 13 fills the open cavity.

[0037] In a feasible embodiment of the present invention, a second through hole 7 extending through the length of the precast column 1 is provided in the middle of the precast column 1. The second through hole 7 is formed of lightweight tubing and is a hollow channel penetrating the column body to reduce the structural weight. The second through hole 7 extends through the entire column body without the need for concrete pouring.

[0038] In a feasible embodiment of the present invention, the first through hole 6 is formed by corrugating tube, the inner wall of the corrugated tube has a rough surface, and the outer periphery of the corrugated tube is provided with spiral ribs 14.

[0039] In a feasible embodiment of the present invention, the through hole of the core area 3 of the precast node is formed by sleeve molding; the inner wall of the sleeve is provided with stiffening ribs or studs to ensure coordinated work with the inner and outer concrete; the node area is formed by post-pouring concrete to form a composite node.

[0040] In one of the above embodiments, the first through hole 6 can be formed using corrugated pipes of various materials, the central second through hole 7 can be formed using various lightweight pipes, and the reinforcing sleeve 16 of the prefabricated node core area 3 can be made of steel pipe or other high-strength materials. Expensive special sleeves and grouting materials are unnecessary; cost-effective materials can be selected according to the actual project conditions, reducing project costs.

[0041] Therefore, this invention employs a system-level collaborative design: the first through holes 6 at the four corners of the column are vertically aligned with the through-holes in the core area 3 of the precast node, forming unobstructed vertical force flow channels; the length of the horizontally extending reinforcements in the core area 3 of the precast node matches the depth of the U-shaped membrane shell 17, ensuring the lap length; the open cavity of the U-shaped membrane shell 17 matches the space of the reserved reinforcement in the node, providing operational space for the lap; the post-cast area at the top of the beam is integrally cast with the post-cast layer of the floor slab, forming a complete horizontal force-bearing system. The matching design and collaborative work between the components make the overall structural performance superior to the simple superposition of the performance of each component.

[0042] In one feasible embodiment of the present invention, the inner wall of the U-shaped membrane shell 17 is provided with a rough surface to ensure adhesion to the post-poured concrete.

[0043] In a feasible embodiment of the present invention, a sealing stirrup 12 is further included, which is connected to the open end of the U-shaped stirrup 8 to form a closed stirrup.

[0044] In a feasible embodiment of the present invention, the surface of the precast base plate of the precast composite floor slab is roughened or indented to ensure adhesion to the post-cast layer; the steel mesh and the upper steel mesh 11 set in the precast base plate are configured according to the stress requirements.

[0045] In a feasible embodiment of the present invention, multiple longitudinal steel bars 5 are provided in the first through hole 6.

[0046] In one specific embodiment, please refer to Figures 1 to 6 The prefabricated concrete frame structure system provided in the embodiments of the present invention.

[0047] It includes precast columns 1, precast beams 2, precast node core area 3, and precast composite floor slabs 4.

[0048] Precast column construction The longitudinal reinforcement of the precast column 1 uses column longitudinal reinforcement 5, which is concentrated at the four corners of the column cross-section and arranged close to the inner wall of the first through holes 6 at the four corners. The column body has a composite cavity, including four first through holes 6 at the four corners and one second through hole 7 in the center. The first through holes 6 at the four corners are formed by corrugated pipes, and their diameter is determined according to the number and diameter of the longitudinal reinforcement to be accommodated at the corner, which can accommodate all the longitudinal reinforcement at that corner and provide sufficient tolerance space for the reinforcement insertion. The second through hole 7 in the center is formed by lightweight pipe, runs through the entire column body, and is not filled with concrete during pouring, forming a permanent hollow channel, which effectively reduces the self-weight of the structure.

[0049] Spiral stirrups 14 are installed around the first through-hole 6 at the four corners, corresponding to the area where the upper and lower longitudinal reinforcement bars overlap, forming a high-constraint zone. The ends of the longitudinal reinforcement bars 5 extending from the top of the column are provided with inwardly bent sections 15, which are used to guide the longitudinal reinforcement bars through the core area of ​​the node and into the first through-hole at the four corners of the upper precast column during hoisting and docking.

[0050] Precast beam construction The precast beam 2 adopts a U-shaped membrane shell 17 throughout its length, meaning the beam's cross-section is U-shaped, precast on three sides, and open at the top. The longitudinal reinforcement of the beam does not extend beyond the beam ends but is embedded in the bottom and side walls of the U-shaped membrane shell 17. U-shaped stirrups 8 are embedded at intervals along the beam length inside the U-shaped membrane shell 17, with the openings facing upwards. The bottom and sides of the stirrups are poured into the concrete of the U-shaped membrane shell 17, with only the top opening exposed. The inner wall of the U-shaped membrane shell 17 has a roughened surface to ensure adhesion to the subsequently poured concrete.

[0051] Prefabricated node core area construction The precast node core area 3 is a factory-prefabricated hollow block, serving as the central area for beam-column connections. Through-holes are located at the four corners of the precast node core area 3, allowing the longitudinal reinforcement of the lower precast column 1 to pass through and extend into the first through-holes 6 at the four corners of the bottom of the upper precast column. Reinforcing sleeves 16 are pre-embedded in the inner walls of the through-holes. Stiffening ribs or studs can be installed on the inner walls of the reinforcing sleeves 16 as needed to ensure coordinated operation with the inner and outer concrete. The precast node core area 3 is equipped with closed stirrups, and lapped reinforcing bars 9 are prefabricated on the four sides of the node, extending into the U-shaped membrane shell 17 of the precast beam 2 to lap with the longitudinal reinforcement of the beam.

[0052] Precast composite floor slab construction The precast composite floor slab 4 is made of precast thin concrete slab with a steel mesh inside. A certain length of end-stretcher 10 extends from the slab end for lap splicing with the continuous reinforcement in the post-cast zone at the top of the beam. The surface of the precast base slab is roughened or indented to ensure adhesion to the post-cast layer. Above the precast base slab, before the post-cast concrete is poured, an upper layer of steel mesh 11 needs to be tied to form bidirectional reinforcement of the composite floor slab.

[0053] All-directional staggered lap splice This system adopts staggered lap joint connection in all directions: Vertical connection: The longitudinal reinforcement 5 of the lower precast column 1 passes through the through-hole of the core area 3 of the precast node, and is guided by the inward bending section 15 at the end to enter the first through-hole 6 at the four corners of the bottom of the upper precast column, overlapping with the longitudinal reinforcement of the upper column in a staggered manner. The spiral stirrups 14 around the first through-hole 6 at the four corners form a strong constraint on the overlapping area. The vertical force flow transmission path is: longitudinal reinforcement of the upper precast column → first through-hole 6 at the four corners of the upper precast column (constrained area of ​​spiral stirrup 14) → through-hole at the four corners of the core area 3 of the precast node → longitudinal reinforcement of the lower precast column.

[0054] Horizontal connection: The open cavity of the U-shaped membrane shell 17 at the end of the precast beam 2 fits onto the horizontally extended lapped steel bars 9 in the core area 3 of the precast node. The longitudinal steel bars of the beam and the horizontally extended lapped steel bars 9 form a staggered lap joint within the U-shaped membrane shell 17. After the beam is hoisted into place, the U-shaped stirrups 8 at the beam end are tied with sealing stirrups 12, which connect with the open end of the U-shaped stirrups 8 to form closed stirrups. The horizontal force flow transmission path is: longitudinal steel bars of the precast beam → lapped with the horizontally extended lapped steel bars 9 in the core area of ​​the node within the U-shaped membrane shell 17 → core area 3 of the precast node.

[0055] Floor slab connection: Precast composite floor slab 4 is laid on precast beam 2, with the slab end protruding steel bars 10 lapped and tied to the continuous steel bars in the post-cast zone at the top of the beam. The upper layer steel mesh 11 is tied according to design requirements, forming a two-way reinforcement system together with the precast bottom slab steel mesh. The post-cast floor slab layer and the post-cast zone at the top of the beam are cast integrally, forming a complete floor load-bearing system. The force flow transmission path of the floor slab is: precast bottom slab steel mesh → upper layer steel mesh 11 of the post-cast layer → slab end protruding steel bars 10 → continuous steel bars in the post-cast zone at the top of the beam → core area 3 of the precast node.

[0056] A second aspect of the present invention provides a construction method for a prefabricated concrete frame structure system, comprising: S1. Factory Prefabrication: Prefabricate columns 1, beams 2, core area of ​​prefabricated nodes 3, and composite floor slabs 4 according to the design drawings. For column 1, corrugated pipes are pre-embedded at the first through-hole 6 at each of the four corners, and lightweight pipes are pre-embedded at the second through-hole 7 in the center. Spiral stirrups 14 are tied around the longitudinal reinforcement lap area outside the first through-hole 6 at each of the four corners. The portion of the longitudinal reinforcement 5 extending beyond the top of the column is pre-bent to form an inwardly bent section 15. For core area of ​​prefabricated nodes 3, reinforcing sleeves 16 are pre-embedded in the four corner ducts, closed stirrups are tied, and lapped reinforcement 9 is reserved. For beam 2, a U-shaped membrane shell 17 is used for the entire beam length, with embedded longitudinal reinforcement. U-shaped stirrups 8 are pre-embedded at intervals along the beam length inside the U-shaped membrane shell 17. For composite floor slab 4, the internal steel mesh is tied, and end-extending reinforcement 10 is reserved at the slab ends.

[0057] S2. Lower-level column installation: Hoist the lower-level precast column 1 into place, and temporarily fix it after correcting its verticality and position.

[0058] S3. Installation of the core area of ​​the node: The prefabricated core area 3 is hoisted into place so that the longitudinal reinforcement of the lower column passes through the four corner through holes of the prefabricated core area 3.

[0059] S4. Beam hoisting: Hoist the precast beam 2 into place so that the open cavity of the U-shaped membrane shell 17 at the beam end fits onto the horizontally extended lapped steel bar 9 in the core area 3 of the precast node. The horizontally extended lapped steel bar 9 extends into the open cavity of the U-shaped membrane shell, forming a staggered lapped relationship with the longitudinal steel bar of the beam.

[0060] S5. Beam end stirrup closure: Tie the sealing stirrup 12 at the top of the beam end. The sealing stirrup 12 is connected to the open end of the U-shaped stirrup 8 pre-embedded inside the U-shaped membrane shell 17 to form a closed stirrup together.

[0061] S6. Floor slab laying: The precast composite floor slab 4 is laid on the precast beam 2, and the steel bars 10 extending from the end of the slab are tied and lapped with the continuous steel bars in the post-cast area at the top of the beam.

[0062] S7. Binding the upper layer of steel mesh: Bind the upper layer of steel mesh 11 above the precast composite floor slab 4.

[0063] S8. Post-casting construction: Concrete is poured integrally into the four corner ducts of the core area 3 of the precast node, the first through hole 6 at the four corners of the column, the open cavity of the U-shaped membrane shell, the post-cast area at the top of the beam, and the post-cast layer of the floor slab to form the overall structure of this floor. The construction of this floor is completed after the concrete reaches the design strength.

[0064] S9. Upper Column Hoisting: Hoist the upper precast column 1, using the inwardly bent section 15 at the end of the lower column's longitudinal reinforcement to guide it through the core area 3 of the precast node and into the first through hole 6 at the four corners of the bottom of the upper column. Repeat steps 2 to 8 to construct the upper layer structure until the overall frame is completed.

[0065] By adjusting the diameter and arrangement of corrugated pipes and lightweight pipes, as well as enhancing the wall thickness and construction measures of the sleeves, the structural stress performance and weight reduction effect can be optimized, significantly reducing the structural self-weight and seismic response. The design of integrally casting the post-cast zone at the beam top with the post-cast layer of the floor slab reduces construction steps while ensuring the integrity of the floor structure. The design of U-shaped stirrups at the beam ends and sealing stirrups forming closed stirrups facilitates the hoisting of precast beams and ensures the sealing and stress performance of the beam end stirrups. The placement of the upper layer of steel mesh in the slab ensures the bidirectional stress performance and integrity of the composite floor slab. The design of the protruding steel bars at the slab ends ensures a reliable connection between the floor slab and the beams and the transfer of force.

[0066] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0068] 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 prefabricated concrete frame structure system, characterized in that, include: The precast column (1) has longitudinal steel bars (5) at the four corners of its cross section. The four corners of the precast column (1) are provided with first through holes (6) along its length. The first through holes (6) are used for the lap splicing of the longitudinal steel bars (5) of the upper and lower precast columns (1). The ends of the longitudinal steel bars (5) extending from the top side of the precast column (1) are provided with inwardly bent sections (15). The core area (3) of the prefabricated node is provided with horizontally extended lapped steel bars (9) on the outer side; through holes are provided at the four corners of the core area (3) of the prefabricated node. The precast beam (2) adopts a U-shaped membrane shell (17), with the top of the U-shaped membrane shell (17) open to form an open cavity; the open cavity is provided with longitudinal beam reinforcement along its length. The precast composite floor slab (4) includes a precast concrete base slab and a post-cast concrete zone (13). The precast concrete base slab is equipped with a steel mesh and has steel bars (10) extending from the slab ends. The post-cast concrete zone (13) is equipped with an upper steel mesh (11). In the vertical direction, the longitudinal steel bars (5) of the lower precast column (1) pass through the through hole and extend into the first through hole (6) of the upper precast column (1), and lap with the longitudinal steel bars (5) of the upper precast column (1); in the horizontal direction, the longitudinal steel bars of the beam lap with the lapped steel bars (9); in the floor direction, the precast composite floor slab is laid on the precast beam (2), and the steel bars (10) extending from the end of the slab lap with the upper steel mesh (11).

2. The prefabricated concrete frame structure system according to claim 1, characterized in that, The entire length of the precast beam (2) is a U-shaped membrane shell. The longitudinal reinforcement of the beam is flush with the end of the precast beam (2). U-shaped stirrups (8) are embedded at intervals along the length of the U-shaped membrane shell. The U-shaped stirrups (8) are embedded inside the U-shaped membrane shell (17) with their openings facing upwards. The bottom and sides are poured into the concrete of the U-shaped membrane shell (17), and the top opening is exposed. The post-cast concrete area (13) is filled into the open cavity.

3. The prefabricated concrete frame structure system according to claim 1, characterized in that, A second through hole (7) is provided in the middle of the precast column (1) to extend through the length of the precast column (1).

4. The prefabricated concrete frame structure system according to claim 1, characterized in that, The first through hole (6) is formed by corrugated tube, the inner wall of the corrugated tube has a rough surface, and the outer periphery of the corrugated tube is provided with spiral ribs (14).

5. The prefabricated concrete frame structure system according to claim 1, characterized in that, The through hole is formed by a sleeve; the inner wall of the sleeve is provided with stiffening ribs or studs.

6. The prefabricated concrete frame structure system according to claim 1, characterized in that, The inner wall of the U-shaped membrane shell (17) is set to a rough surface.

7. The prefabricated concrete frame structure system according to claim 2, characterized in that, Also includes: The sealing stirrup (12) is connected to the open end of the U-shaped stirrup (8) to form a closed stirrup.

8. The prefabricated concrete frame structure system according to claim 1, characterized in that, The surface of the precast concrete base plate of the precast composite floor slab (4) is roughened or indented.

9. The prefabricated concrete frame structure system according to claim 1, characterized in that, Multiple longitudinal steel bars (5) are installed inside the first through hole (6).

10. A construction method for a prefabricated concrete frame structure system, characterized in that, include: S1. Factory prefabrication: Prefabricate precast columns (1), precast beams (2), precast composite floor slabs (4) and precast node core areas (3) according to the design drawings; When prefabricating precast columns (1), first through holes (6) are reserved at the four corners and second through holes (7) are reserved in the center. Spiral stirrups (14) are set in the lap area of ​​longitudinal reinforcement outside the first through hole (6). The part of the longitudinal reinforcement (5) of the column extending out of the column top is pre-bent to form an inwardly bent section (15); When prefabricating node core areas (3), reinforcing sleeves (16) are pre-embedded in the four corner holes, closed stirrups are tied, and lap reinforcement (9) is reserved; When prefabricating beams (2), the entire beam adopts the form of a U-shaped membrane shell (17), the longitudinal reinforcement of the beam is pre-embedded, and U-shaped stirrups (8) are pre-embedded at intervals along the beam length inside the U-shaped membrane shell (17); When prefabricating composite floor slabs (4), the steel mesh inside the slab is tied, and the extended reinforcement is reserved at the end of the slab. S2. Lower column installation: The lower precast column (1) is hoisted into place, and its verticality and position are corrected before temporary fixing. S3, Installation of the node core area: The prefabricated node core area (3) is hoisted into place so that the longitudinal reinforcement of the lower column passes through the four corner through holes of the node core area; S4. Beam hoisting: Hoist the precast beam (2) into place so that the open cavity of the U-shaped membrane shell (17) at the beam end fits onto the horizontally extended lapped steel bar (9) in the core area of ​​the node. The horizontally extended lapped steel bar (9) extends into the open cavity of the membrane shell and forms a staggered lapped relationship with the longitudinal steel bar of the beam. S5. Beam end stirrup closure: Tie a sealing stirrup (12) at the top of the beam end. The sealing stirrup (12) is connected to the open end of the U-shaped stirrup (8) pre-embedded inside the U-shaped membrane shell (17) to form a closed stirrup together. S6. Floor slab laying: The precast composite floor slab (4) is laid on the precast beam (2), and the steel bars (10) extending from the end of the slab are tied and lapped with the continuous steel bars in the post-cast area of ​​the beam top. S7. Binding the upper layer of steel mesh (11): Bind the upper layer of steel mesh (11) above the precast composite floor slab (4); S8. Post-pouring construction: Concrete is poured in the four corner through holes of the core area of ​​the node, the first through hole (6) of the four corner of the column, the open cavity of the U-shaped membrane shell (17), the post-pouring area of ​​the beam top and the post-pouring layer of the floor slab to form the overall structure of this layer. S9. Upper column hoisting: After the concrete of this layer reaches the strength, hoist the upper precast column (1), and use the inward bending section (15) at the end of the longitudinal reinforcement of the lower column to guide it through the core area of ​​the node and into the first through hole (6) at the four corners of the bottom of the upper column. Repeat S2 to S8 to carry out the construction of the upper layer.

Images