A steel-concrete composite structure precast beam

Abstract

The utility model relates to prefabricated beam of steel -concrete combined structure in the technical field of fabricated building structure, specifically relates to prefabricated beam of steel -concrete combined structure, and prefabricated beam of steel -concrete combined structure adopts the combination of reinforced concrete beam section, beam end steel structure connecting assembly and beam bottom steel structure embedded part, and beam column joint, beam wall joint, beam plate joint basically cancel cast-in-situ concrete operation, compared with traditional wet operation amount reduction > 80%, single node construction time -consuming shortening, construction waste reduction > 50%, directly bear floor load by concrete overhanging lug plate, cancel the erection of full hall scaffold, beam end steel structure connecting assembly is installed after beam end instant formation stable frame structure, save temporary support cost 12~16%, the installation efficiency of floor, wallboard is improved significantly, the installation of the main body structure of steel -concrete combined structure prefabricated beam only needs hoisting shift operation, since most of the technology has been integrated in the component by component factory, multi -process integration, cross operation reduces 80%, is favorable for reducing the density of on -the -spot personnel, saves manpower cost expenditure.

Description

Technical Field

[0001] This utility model relates to the field of prefabricated building structure technology, specifically to a prefabricated beam with a steel-concrete composite structure. Background Technology

[0002] With the acceleration of industrialization in the construction industry, precast concrete beams, as the core horizontal components of prefabricated structures, directly affect construction speed and building quality through their connection efficiency and structural performance.

[0003] In current prefabricated building construction, the application of precast concrete beams still relies on traditional connection and construction methods, which has the following drawbacks: (1) In terms of floor slab installation, a large number of temporary supports need to be set up to bear the floor slab load, which leads to the extension of the construction period. The erection and dismantling are time-consuming and labor-intensive, which restricts the construction progress.

[0004] (2) In beam-column joint connections, wet construction methods are often used, and the on-site concrete pouring process is cumbersome. The construction quality of traditional wet construction joints is greatly affected by the on-site environment, the force transmission path is unclear, there are structural safety hazards, and the reliability of beam-column joint connections is insufficient. High proportion of wet construction: The construction time of wet construction joints is 2.1 times that of dry connections, and it is easy to generate construction waste, which does not conform to the concept of green construction.

[0005] (3) The beam-wall connection is not flexible, lacks standardized pre-embedded structure, and the wall installation accuracy is low and the stability is insufficient.

[0006] Based on the above, it is clear that the current technical system still suffers from a series of problems that urgently need to be addressed, including low efficiency in floor slab installation, high costs of temporary supports, insufficient reliability of beam-column joint connections, and a high proportion of wet work. Therefore, there is an urgent need for a precast steel-concrete composite structure beam to solve the problems existing in the current technology. Utility Model Content

[0007] The purpose of this utility model is to provide a precast steel-concrete composite structure beam, which is a solution for precast steel-concrete composite structure beams that has undergone multiple optimizations to address the technical problems of existing systems. This solution achieves higher on-site assembly, eliminates the need for supports and formwork, and enables completely dry operation at joints. The specific technical solution is as follows: A precast steel-concrete composite beam includes a reinforced concrete beam segment, steel structure connection components at the beam ends, and steel structure embedded parts at the bottom of the beam. The reinforced concrete beam segment includes beam segment skeleton reinforcement and a concrete layer; the beam segment skeleton reinforcement includes interconnected beam body longitudinal reinforcement and beam body stirrups; The beam end steel structure connection assembly is installed at at least one end of the reinforced concrete beam segment; The steel structure embedded parts at the bottom of the beam are set at the bottom of the reinforced concrete beam segment; The side of the reinforced concrete beam segment is provided with a concrete cantilever slab that can overlap with the floor slab. The concrete cantilever slab includes a cantilever slab skeleton reinforcement and a concrete layer. The cantilever slab skeleton reinforcement includes interconnected cantilever longitudinal bars and cantilever stirrups. The concrete cantilever slab is provided with at least one connector that corresponds to the installation hole reserved on the floor slab. At least one rebar connection groove is provided at the top of the reinforced concrete beam segment, and the protruding rebars on the floor slab are connected to the rebar connection groove.

[0008] This utility model's precast steel-concrete composite beam utilizes a combination of reinforced concrete beam segments, steel structure connecting components at the beam ends, and embedded steel structure components at the beam bottom. The cast-in-place concrete work is largely eliminated at beam-column, beam-wall, and beam-slab joints, reducing wet work by >80% compared to traditional prefabricated concrete structures, shortening construction time per node, and reducing construction waste by >50%. The concrete cantilevered slabs directly bear the floor load, eliminating the need for full-scale scaffolding. The beam ends, connected by steel structure connecting components, immediately form a stable frame structure, saving 12-16% on temporary support costs and significantly improving the installation efficiency of floor slabs and wall panels. The installation of the main structure of the precast steel-concrete composite beam requires only a hoisting team, eliminating the need for reinforcement workers, formwork workers, and concrete workers. Since most processes are integrated into the components by the component factory, multi-process integration and cross-operation are reduced by 80%, which helps reduce on-site personnel density and save labor costs.

[0009] Preferably, the connectors on the concrete cantilever slab are equipped with anchor heads; the connectors are configured one-to-one with the pre-drilled mounting holes on the floor slab. This further enhances the stability of the connection between the concrete cantilever slab and the floor slab.

[0010] Preferably, the concrete cantilever slab is provided with an asphalt felt and a cement mortar leveling layer; a filling layer, a PE rod, a sealant layer, and a grout layer are also provided between the connector and the pre-drilled installation hole on the floor slab to form a solidified joint; a mortar layer is provided on the outside of the solidified joint. The setting of the solidified joint further enhances the stability of the connection; the mortar layer can effectively correct the appearance and extend the service life of the solidified joint.

[0011] Preferably, the protruding reinforcing bars on the floor slab extend out of the top layer and the bottom layer respectively; the protruding reinforcing bars extend into the reinforcing bar connection groove for connection; a concrete layer is provided at the connection between the protruding reinforcing bars on the floor slab and the reinforcing bar connection groove for reinforcement.

[0012] Preferably, the ends of the surface reinforcement bars on the floor slab are connected to the surface reinforcement bars of the adjacent floor slab as a whole by bending the reinforcement bars to increase the anchorage length or by mechanical connection or welding connection.

[0013] Preferably, the beam-end steel structure connection assembly is an H-beam with cut ends, the main body of which is enclosed within the reinforced concrete beam segment and the web is exposed outside the reinforced concrete beam segment; connection holes are provided on the exposed web; and reinforcing connectors are provided on the surface of the H-beam. Through the combined design of high-strength bolts and connection holes, dry connection between the precast beam and column can be achieved; the design of the reinforcing connectors enhances their synergistic performance with the concrete.

[0014] Preferably, the embedded steel structure component at the bottom of the beam includes an embedded steel plate and a node plate set on the embedded steel plate; the embedded steel plate is connected to the reinforced concrete beam segment through embedded anchor bars; the ends of the embedded anchor bars are provided with bent portions or anchor heads, and the embedded anchor bars are fixedly connected to the embedded steel plate by through-hole plug welding. The precast wall panel can be connected and fixed to the node plate through pin joints, which is convenient to operate.

[0015] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1 This is a schematic diagram of the precast steel-concrete composite beam in this embodiment; Figure 2 yes Figure 1 Front view of the precast steel-concrete composite beam structure; Figure 3 yes Figure 1 Top view of the precast steel-concrete composite beam structure; Figure 4 yes Figure 1 Schematic diagram of the embedded parts at the bottom of the central beam; Figure 5 yes Figure 1 Schematic diagram of the middle beam end connection component; Figure 6 yes Figure 1 Schematic diagram of the connection node between the beam and slab; Figure 7 yes Figure 1 Top view of the beam-slab connection node; Among them, 1. Reinforced concrete beam segment, 101. Longitudinal reinforcement of beam body, 102. Stirrups of beam body; 2. Steel structure connection components at beam ends, 201. Steel joint, 202. Reinforcing connector, 203. Connection hole; 3. Embedded steel structure components at the bottom of beam, 301. Node plate, 302. Embedded steel plate, 303. Embedded anchor bar; 4. Concrete cantilever ear plate, 401. Longitudinal reinforcement of cantilever ear, 402. Stirrups of cantilever ear; 5. Connector, 501. Anchor head, 502. Filling layer, 503. PE rod, 504. Sealant layer, 505. Mortar layer, 506. Grout layer, 507. Cement mortar leveling layer, 508. Asphalt felt; 6. Reinforcing bar connection groove; 7. Precast floor slab, 701. Floor slab reinforcement, 702. Concrete layer. Detailed Implementation

[0017] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0018] Example: See Figures 1-7 A precast steel-concrete composite beam specifically includes a reinforced concrete beam segment 1, a steel structure connection assembly at the beam end 2, and a steel structure embedded part 3 at the bottom of the beam. The detailed structure is as follows: The reinforced concrete beam segment 1 is the main structural element, comprising the beam segment skeleton reinforcement and a concrete layer; the beam segment skeleton reinforcement includes interconnected longitudinal reinforcement 101 and stirrups 102, as detailed below. Figure 1 and Figure 2 Concrete of strength grade C30 or above is used for pouring. The beam body is equipped with longitudinal reinforcement 101 of grade HRB400 or above and stirrups 102 of grade HPB300 / HRB400. The diameter of the longitudinal reinforcement is generally selected as φ20~25mm according to the stress calculation, and the diameter of the stirrups shall not be less than φ8mm. The spacing is set according to the seismic requirements.

[0019] The reinforced concrete beam segment 1 has a concrete cantilevered slab 4 on its side, which can overlap with the floor slab. The concrete cantilevered slab 4 includes a cantilevered slab skeleton reinforcement and a concrete layer. The cantilevered slab skeleton reinforcement includes interconnected cantilevered longitudinal bars 401 and cantilevered stirrups 402. At least one connector 5 is provided on the concrete cantilevered slab 4, corresponding to the installation holes reserved on the floor slab (precast floor slab can be used here). Preferably, the connector 5 on the concrete cantilevered slab 4 is provided with an anchor head 501. The connector 5 is provided one-to-one with the installation holes reserved on the floor slab. The concrete cantilevered slab 4 is provided with asphalt felt 508 and cement mortar leveling layer 507. A filling layer 502, a PE rod 503, a sealant layer 504, and a grout layer 506 are also provided between the connector 5 and the installation holes reserved on the floor slab to form a consolidation node. A mortar layer 505 is provided on the outside of the consolidation node. See details. Figure 6The protruding reinforcing bars on the floor slab extend out of the top and bottom layers respectively; the protruding reinforcing bars are connected by inserting them into the reinforcing bar connection groove; a concrete layer 702 is provided at the connection between the protruding reinforcing bars on the floor slab and the reinforcing bar connection groove 6 to reinforce the connection, see details. Figure 7 The ends of the surface reinforcement bars on the floor slab are connected to the surface reinforcement bars of the adjacent floor slab as a whole by bending the reinforcement bars to increase the anchorage length or by mechanical connection or welding connection. In this embodiment, the concrete cantilever slab 4 is provided with cantilever longitudinal reinforcement bars 401 and cantilever stirrups 402, see details. Figure 3 Its dimensions and reinforcement are determined according to structural calculations; anchor bolts (i.e. connectors 5) with anchor heads are pre-embedded on the top surface of the cantilever, and the bolt spacing corresponds one-to-one with the reserved holes on the floor slab.

[0020] The beam-end steel structure connection assembly 2 is disposed at at least one end of the reinforced concrete beam segment 1. In this preferred embodiment, the beam-end steel structure connection assembly 2 is detailed below. Figure 5 Specifically, a steel section joint 201 is used, which is a Q355B grade H-beam with cut ends. Its main body is encased in the reinforced concrete beam segment 1 and its web is exposed outside the reinforced concrete beam segment 1. A connection hole 203 is opened on the exposed web. Here, the connection hole 203 is preferably a high-precision bolt hole for passing through a 10.9 grade high-strength bolt. The surface of the H-beam is provided with a reinforcing connector 202. The reinforcing connector 202 is preferably a Φ19×80mm stud. The spacing is set according to the shear resistance requirements of the steel-concrete interface to enhance the synergistic performance with the concrete.

[0021] The steel structure embedded part 3 at the bottom of the beam is installed at the bottom of the reinforced concrete beam segment 1. In this preferred embodiment, the steel structure embedded part 3 at the bottom of the beam is detailed below. Figure 4 Specifically, it includes a pre-embedded steel plate 302 and a node plate 301 set on the pre-embedded steel plate 302; the pre-embedded steel plate 302 is connected to the reinforced concrete beam segment 1 through pre-embedded anchor bars 303; the ends of the pre-embedded anchor bars 303 are provided with bent parts or anchor heads, and the pre-embedded anchor bars 303 are fixedly connected to the pre-embedded steel plate 302 by through-hole plug welding. More preferably, the pre-embedded steel plate is Q355B grade, the pre-embedded anchor bars are HRB400 grade, the thickness of the pre-embedded steel plate is 16~25mm, and the Φ16~Φ20mm pre-embedded anchor bars are fixed by through-hole plug welding. The ends of the pre-embedded anchor bars can be bent or provided with anchor heads to shorten the anchorage length; the node plate is used for the pin connection of the wall panel. When the production is carried out flat, the node plate is not welded to the contact surface of the mold table temporarily, and is welded later.

[0022] At least one steel bar connection groove 6 is provided at the top of the reinforced concrete beam segment 1, and the outward steel bars on the floor slab are connected to the steel bar connection groove 6.

[0023] Applying the technical solution of this embodiment, the key processes of factory prefabrication and on-site construction operation are as follows: I. Key processes in factory prefabrication: The beam end steel structure connection component 2 (i.e., the beam end H-beam) is precisely cut in a specialized factory, and the end cutting ensures the flatness of the connection surface. Gas shielded welding is used when welding the reinforcing connector 202 (i.e., the weld stud), and the weld quality reaches level two or above. The connection hole 203 (i.e., the web bolt hole) must be of guaranteed precision. The embedded steel plate 302 and the embedded anchor bar 303 of the beam bottom embedded part are connected by through-hole plug welding. After welding, the weld slag is cleaned and the welding quality is inspected.

[0024] High-precision steel molds are used in the fabrication of precast beams for steel-concrete composite structures. The H-beams at the beam ends are fixed according to the design, ensuring accurate embedment depth and exposed web position. When tying the longitudinal reinforcement 101 of the beam body, it is welded to the upper and lower flanges of the H-beams, with a weld length ≥ 5d (d is the diameter of the longitudinal reinforcement). Simultaneously, the longitudinal reinforcement 401 and stirrups 402 of the cantilevered concrete ear plates 4 are tied to ensure the concrete cover thickness meets requirements. Where reinforcement connection grooves 6 are required, the groove size is pre-reserved to match the diameter of the floor slab reinforcement, ensuring continuity of the steel reinforcement on the beam.

[0025] II. On-site construction operation procedures: Before hoisting, the position of the column connection node was checked. Using a special hoisting tool in the existing technology, the reinforced concrete beam segment 1 was hoisted to the installation position, so that the exposed web of the H-beam at the beam end was aligned with the column node. After temporary fixation, the elevation and level of the beam were adjusted, and then the high-strength bolts were tightened in stages.

[0026] Before hoisting the floor slab, lay asphalt felt 508 and a 20mm thick cement mortar leveling layer 507 on the concrete cantilever ear plate 4 in sequence. After curing to a strength ≥15MPa, hoist the precast floor slab 7, aligning the reserved holes of the floor slab with the connecting parts 5 (i.e., the ear plate fixing bolts). The gap between the precast floor slab 7 and the concrete cantilever ear plate 4 is filled with a filling layer 502 (i.e., polystyrene board 2). PE rods 503 and a sealant layer 504 are then embedded on the outside in sequence. The bolt holes are filled with a grout layer 506 (i.e., CGM grout). After curing, the surface is smoothed with a filling mortar layer 505. For high-stress areas, the slab reinforcement 701 on the surface layer of the precast floor slab needs to extend beyond the Lae length (seismic anchorage length) and into the top beam reinforcement connection groove 6. The slab reinforcement 701 on the bottom layer should be extended short. The ends of the slab reinforcement on the floor slab should be bent, mechanically connected or welded to the adjacent slab reinforcement to form an integral whole. A concrete layer 702 (i.e., UHPC layer) should be poured into the groove and cured to the design strength.

[0027] When a wall panel is required below reinforced concrete beam segment 1, the node plate 301 is welded to the embedded steel plate 302 according to the position of the wall panel, and the weld length is ≥10d (d is the thickness of the node plate). The wall panel is connected and fixed to the node plate by a pin.

[0028] The technical solution applied in this embodiment is as follows: The sides of the main reinforced concrete beam segment need to be designed with concrete cantilevered ear plates according to the structural layout, which are used to overlap the precast floor slab and achieve support-free operation; the steel structure connection components at the beam ends are arranged at both ends of the beam length, and longitudinal bars, stirrups and bent-up bars are arranged between them according to the structural calculation. The longitudinal bars and bent-up bars need to be precisely welded to the upper and lower flange plates of the end components according to their positions (weld length ≥ 5d (bar diameter)).

[0029] The concrete cantilever slabs need to be equipped with stirrups and longitudinal bars according to structural calculations, and high-strength connecting bolts (M20 grade, with anchor heads) should be pre-embedded at the top of the slab to match the reserved ducts in the precast floor slab. For areas with large loads, steel bar connection grooves should be opened at the top of the main beam segment, with the groove size matching the diameter of the floor slab steel bars. The steel bars on the beams should be retained, and the floor slab steel bars can be connected to the adjacent floor slabs by hook lap splicing, welding or mechanical connection to form a continuous force system.

[0030] Regarding key details: The beam end connection assembly uses H-beams with machined ends. The main section is embedded in concrete, with only the web of the machined section exposed as the connection surface. High-precision bolt holes are drilled in the exposed web. Studs are welded to the sides of the H-beam web embedded in the concrete, significantly improving the shear resistance of the steel-concrete interface. The beam bottom embedded part of this utility model consists of an embedded steel plate and a welded node plate. The embedded steel plate is fixed with anchor bars by through-hole plug welding. Considering the production process limitations of the flat formwork, only an embedded plate is set at the contact surface of the embedded part with the formwork. The position is adjusted according to the wall layout, and the node plate is welded later.

[0031] The technical solution of this embodiment has the following advantages: First, the fully dry construction system: Beam-column joints (H-beam bolt connections), beam-wall joints (embedded pin connections), and beam-slab joints (bolt-grouting / UHPC grooves) essentially eliminate cast-in-place concrete work. Compared to traditional prefabricated concrete structures, this reduces wet work by >80%, shortens construction time per joint, and reduces construction waste by >50%.

[0032] Second, the support-free structural system: the floor load is directly borne by the cantilevered concrete slabs, eliminating the need for full-scale scaffolding. The beam ends are connected by H-beam end joints, instantly forming a stable frame structure. This process saves 12-16% on temporary support costs and significantly improves the installation efficiency of floor slabs and wall panels.

[0033] Third, optimization of construction trades and manpower: The installation of the main structure only requires the hoisting team, eliminating the need for reinforcement workers, formwork workers, and concrete workers. Since most processes have been integrated into the components by the component factory, multi-process integration and cross-operation are reduced by 80%. This helps reduce on-site personnel density and saves labor costs.

[0034] Fourth, improved structural reliability: The collaborative working performance of the steel-concrete composite interface is enhanced by reinforcing bars and studs, realizing an effective force transmission path. Moreover, the steel structure connection technology is quite mature, and the node calculation model of the steel-concrete composite precast beam can be designed with reference to the steel structure logic.

[0035] This implementation method achieves high efficiency and structural reliability in precast beam construction through standardized prefabrication and dry connection, and is suitable for beam component installation in low-rise and multi-story prefabricated buildings.

[0036] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A precast beam with a steel-concrete composite structure, characterized in that, It includes reinforced concrete beam segments (1), steel structure connection components at beam ends (2), and steel structure embedded parts at the bottom of beams (3); The reinforced concrete beam segment (1) includes beam segment skeleton reinforcement and concrete layer; the beam segment skeleton reinforcement includes interconnected beam body longitudinal reinforcement (101) and beam body stirrups (102). The beam end steel structure connection assembly (2) is provided at at least one end of the reinforced concrete beam segment (1); The steel structure embedded part (3) at the bottom of the beam is set at the bottom of the reinforced concrete beam segment (1); The side of the reinforced concrete beam segment (1) is provided with a concrete cantilever slab (4) that can overlap with the floor slab. The concrete cantilever slab (4) includes a cantilever slab skeleton reinforcement and a concrete layer. The cantilever slab skeleton reinforcement includes interconnected cantilever longitudinal reinforcement (401) and cantilever stirrups (402). At least one connector (5) is provided on the concrete cantilever slab (4) that corresponds to the installation hole reserved on the floor slab. At least one steel bar connection groove (6) is provided at the top of the reinforced concrete beam segment (1), and the outward steel bars on the floor slab are connected to the steel bar connection groove (6).

2. The precast steel-concrete composite structure beam according to claim 1, characterized in that, An anchor head (501) is provided on the connector (5); The connector (5) is set one-to-one with the pre-drilled mounting holes on the floor.

3. The precast steel-concrete composite structure beam according to claim 2, characterized in that, The concrete cantilever ear plate (4) is provided with asphalt felt (508) and cement mortar leveling layer (507); A filling layer (502), a PE rod (503), a sealant layer (504), and a grout layer (506) are provided between the connector (5) and the pre-reserved installation hole on the floor to form a solidified node; a mortar layer (505) is provided on the outside of the solidified node.

4. The precast steel-concrete composite structure beam according to claim 3, characterized in that, The protruding reinforcing bars on the floor slab extend out of the top and bottom layers respectively; the protruding reinforcing bars are connected by inserting them into the reinforcing bar connection groove. A concrete layer (702) is provided at the connection between the outward reinforcing bars on the floor slab and the reinforcing bar connection groove (6) to reinforce the connection.

5. The precast steel-concrete composite structure beam according to claim 4, characterized in that, The ends of the surface reinforcement bars on the floor slab are connected to the surface reinforcement bars of the adjacent floor slab as a whole by bending the reinforcement bars to increase the anchorage length or by mechanical connection or welding connection.

6. The precast steel-concrete composite beam according to any one of claims 1-5, characterized in that, The beam end steel structure connection component (2) is an H-beam with cut ends. Its main body is enclosed in the reinforced concrete beam segment (1) and its web is exposed on the reinforced concrete beam segment (1). Connection holes (203) are opened on the exposed web. The surface of the H-beam is provided with reinforcing connectors (202).

7. The precast steel-concrete composite structure beam according to any one of claims 1-5, characterized in that, The embedded steel structure component (3) at the bottom of the beam includes an embedded steel plate (302) and a node plate (301) set on the embedded steel plate (302); the embedded steel plate (302) is connected to the reinforced concrete beam segment (1) through embedded anchor bars (303); the end of the embedded anchor bar (303) is provided with a bent part or an anchor head, and the embedded anchor bar (303) is fixedly connected to the embedded steel plate (302) by through-hole plug welding.

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