Steel-concrete laminated slab composite beam structure and assembly method

Abstract

The invention discloses a steel-concrete laminated slab composite beam structure and an assembly method, the structure comprises a steel plate shear connector, the left side and the right side of the steel plate shear connector are symmetrically provided with a group of concrete prefabricated bottom plates respectively, and a concrete post-pouring layer is arranged above the concrete prefabricated bottom plates; a plurality of clamping grooves are formed in the upper end of the steel plate shear connector, transverse additional steel bars are clamped in the clamping grooves, and the transverse additional steel bars extend to the left side and the right side to the position below the concrete post-pouring layer; each concrete prefabricated bottom plate comprises a middle plate and end plates located at the front end and the rear end of the middle plate, the upper surface of each middle plate and the upper surface of each end plate are each provided with a plurality of dovetail grooves in the front-back direction, and a plurality of seam splicing steel bars are jointly connected into the coaxial dovetail grooves in a clamped mode. The structure solves the problem that a traditional steel-concrete composite beam anti-shear connecting piece is limited in anti-shear performance; the prefabricated bottom plate is low in production efficiency and difficult to hoist and transport; during construction of plate end and plate side connecting structures, horizontal reinforcing steel bars conflict, and transverse additional reinforcing steel bars and abutted seam reinforcing steel bars are difficult to position.

Description

Technical Field

[0001] The present invention relates to the technical field of building structures, and particularly relates to a steel-concrete composite slab composite beam structure and an assembly method thereof. Background Art

[0002] Steel-concrete composite beams can make full use of the mechanical properties of steel and concrete, and have the advantages of small self-weight, high bearing capacity, and large stiffness. With the development of prefabricated buildings, composite beams composed of composite slabs and steel beams have been widely used in the engineering field due to the advantages of less on-site wet work, low formwork usage, and high construction efficiency. The traditional steel-concrete composite slab composite beam mainly connects the concrete composite slab and the steel beam into a whole through stud shear connectors. Although the stud shear connectors have simple structures and strong applicability, their shear bearing capacity and stiffness are limited, resulting in a reduction in the cooperative action between the steel beam and the concrete composite slab, and the overall performance of the composite beam cannot be fully exerted. Moreover, there is stress concentration around the studs, which is likely to cause local concrete crushing and splitting cracks.

[0003] At present, the concrete composite slab in the composite beam is composed of a precast bottom slab and a cast-in-place concrete slab. The end of the precast bottom slab needs to extend out reinforcing bars, which are commonly known as beard bars in the industry. The existence of the extended reinforcing bars not only brings many inconveniences to the production, hoisting, and transportation of the bottom slab, but also at the plate end support, the extended reinforcing bars are prone to collision and crossing with each other and with the stud shear connectors, resulting in a complex end connection structure and increasing the construction difficulty. In recent years, a method of not extending bars at the plate end support has been proposed, that is, placing additional reinforcing bars at the connection between the end of the precast bottom slab and the steel beam to replace the beard bars. However, practice has proved that the placed additional reinforcing bars are prone to displacement during the subsequent concrete pouring.

[0004] Due to limitations in size and transportation conditions, the precast bottom slabs in the concrete composite slabs need to be spliced together in multiple pieces. The traditional lateral joint forms of the bottom slabs mainly include integral joints and separated joints. The integral joint usually adopts the form of a post-cast strip. Although this joint has good overall performance, the plate side needs to extend out reinforcing bars, which not only reduces the production and construction efficiency of the bottom slab, but also additional formwork needs to be added at the post-cast strip, increasing the construction process and prolonging the construction period. Compared with the integral joint, the separated joint does not need to extend out reinforcing bars on the plate side, and only additional reinforcing bars need to be placed on the plate top. The joint structure is relatively simple. However, the distance between the additional reinforcing bars on the plate top and the bottom slab reinforcing bars is relatively far along the plate thickness direction, making it difficult to achieve two-way force transfer of the plate, and there is a problem of displacement of the additional reinforcing bars on the plate top during the construction process.

[0005] In recent years, a slotted close joint structure has been proposed for the lateral splicing of composite slabs. However, the research results show that this joint structure is prone to cracking of the composite surface near the joint, so the joint structure needs to be further optimized. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the present invention proposes a steel-concrete composite slab composite beam structure and an assembly method. This structure can solve the problems of limited shear resistance of traditional steel-concrete composite beam structures, which are prone to cause local concrete cracking and crushing; low production efficiency of precast bottom slabs, difficult hoisting and transportation; conflicts of beard bars during construction at the slab ends and sides, and difficulties in positioning transverse additional steel bars and joint steel bars.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows: A steel-concrete composite slab composite beam structure includes steel plate shear connectors. On the left and right sides of the steel plate shear connectors, a group of concrete precast bottom slabs are symmetrically arranged respectively. Above the concrete precast bottom slabs, there is a concrete cast-in-place layer. At the upper end of the steel plate shear connectors, multiple card slots are arranged at intervals. Transverse additional steel bars are clamped in the card slots, and the transverse additional steel bars extend to the lower part of the concrete cast-in-place layer on both the left and right sides. Each group of concrete precast bottom slabs includes an intermediate slab and end slabs located at the front and rear ends of the intermediate slab. On the upper surfaces of the intermediate slab and the end slabs, multiple dovetail grooves running in the front and rear directions are arranged. Multiple joint steel bars are jointly clamped in the coaxial dovetail grooves.

[0008] Preferably, elastic limit blocks for restricting the upward movement of the transverse additional steel bars are arranged on the side walls of the card slots.

[0009] Preferably, the elastic limit blocks include a spring and a rubber block connected to each other. The end of the spring away from the rubber block is connected to the side wall of the card slot.

[0010] Preferably, the card slots are U-shaped grooves.

[0011] Preferably, there is a set distance between the end of the concrete precast bottom slab and the steel plate shear connector.

[0012] Preferably, hinges are arranged on the side walls of the dovetail grooves. The support shaft of the hinge is located at the top of the dovetail groove. The widths of the two link plates of the hinge are different. Among them, the long link plate is connected to the side wall of the dovetail groove, and the short link plate is suspended.

[0013] Preferably, the hinge is installed at the end of the dovetail groove on the end plate.

[0014] Preferably, the hinge is a 30-degree hinge or a 45-degree hinge, and at least one through hole is arranged on the link plate.

[0015] Preferably, two groups of elastic limit blocks are symmetrically arranged in each card slot, and two groups of hinges are symmetrically arranged in each dovetail groove.

[0016] Preferably, a steel beam is provided below the steel plate shear connector, and the precast concrete floor slab is lapped above the steel beam.

[0017] Preferably, the dovetail grooves on the intermediate plate are of a structure that is transparent from front to back, and the dovetail grooves on the end plate are of a structure with an opening at one end close to the intermediate plate and a closed end at the other end.

[0018] The present application also discloses an assembly method for the above composite beam structure, which is specifically as follows: Step 1: Process multiple parallel card slots at the upper end of the steel plate shear connector, and install elastic limit blocks on the side walls of the card slots; Step 2: Prefabricate an intermediate plate and an end plate with dovetail grooves and hinges on the side walls of the dovetail grooves; Step 3: Weld the steel plate shear connector above the steel beam, and lap the intermediate plate and the end plate correspondingly on the right-angle support platform composed of the steel plate shear connector and the H-shaped steel beam; Step 4: Align the intermediate plate and the end plate laterally, snap the joint steel bars between the two hinges of the dovetail groove, and snap the transverse additional steel bars into the card slots; Step 5: Pour concrete above the intermediate plate, the end plate and the steel plate shear connector to form a concrete post-cast layer.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Compared with the stud shear connectors in traditional composite beams, the card slots and elastic limit blocks in the steel plate shear connectors facilitate the positioning of transverse additional steel bars, and can effectively solve the problem of displacement of transverse additional steel bars during construction.

[0020] 2. The card slots in the steel plate shear connector form a mortise and tenon fit with the concrete and the transverse additional steel bars, significantly improving the shear resistance, reducing the slip at the interface between the steel beam and the concrete, and enhancing the overall mechanical performance of the steel-concrete composite slab composite beam.

[0021] 3. The steel plate shear connector can set different card slot sizes and spacings according to the diameter and number of transverse additional steel bars, with strong applicability.

[0022] 4. The present invention eliminates the end extended steel bars of the precast concrete floor slab, and directly sets the transverse additional steel bars passing through the card slots of the steel plate shear connector at the connection between the precast concrete floor slab and the steel beam, simplifying the end structure, effectively solving the problem of cross collision caused by the end extended steel bars, and improving the production and construction efficiency.

[0023] 5. The present invention eliminates the externally extended steel bars on the side of the precast concrete bottom slab. By arranging dovetail grooves along the width direction of the bottom slab, i.e., the front-back direction, where the through dovetail grooves are arranged on the middle slab, and the dovetail grooves are arranged on the end slab on the side close to the middle slab. Each precast concrete bottom slab is directly and closely joined. The joint steel bars are placed in the aligned dovetail grooves, and the upward movement of the joint steel bars is restricted by hinges, thereby improving the overall mechanical properties of the closely joined joints.

[0024] 6. Compared with the post-cast strip joint, the present invention not only solves the problems of low production efficiency of the bottom slab and high construction difficulty caused by the externally extended steel bars, but also simplifies the joint structure on the side of the bottom slab, reduces the formwork erection at the joint, and lowers the construction difficulty. Compared with the separated joint, the through dovetail grooves arranged along the width direction of the slab facilitate the positioning of the joint steel bars, and the dovetail grooves can increase the effective height of the joint steel bars, making the lateral force transfer of the slab more effective, and thus realizing the two-way force transfer of the slab.

[0025] 7. The dovetail grooves with wider upper part and narrower lower part arranged along the width direction of the slab form a wedge effect with the post-cast concrete, generating a self-locking effect in the force direction. Compared with ordinary strip grooves, it can effectively improve the biting effect between the precast bottom slab and the post-cast layer concrete. The chain plate of the hinge is increased with through holes, and the integral embedded connection between the hinge and the concrete slab can be realized both during the production of the precast bottom slab and during the post-cast concrete pouring, with strong firmness and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is Figure 1 a partial enlarged view of A in Figure 3 is a structural diagram of the overall structure after removing the post-cast concrete layer; Figure 4 is Figure 3 a partial enlarged view of B in Figure 5 is a top view of the overall structure of the present invention; Figure 6 is Figure 5 a sectional view taken along C-C in Figure 7 is Figure 6 a partial enlarged view of E in Figure 8 is Figure 5 a sectional view taken along D-D in Figure 9 is Figure 8 a partial enlarged view of F in

[0027] In the figure: 1. Horizontal additional reinforcement; 2. Steel beam; 3. End plate; 4. Intermediate plate; 5. Post-cast concrete layer; 6. Steel plate shear connector; 7. Rubber block; 8. Spring; 9. Joint reinforcement; 10. Long chain plate; 11. Short chain plate. Detailed implementation mode

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0029] Embodiment 1: The present invention discloses a steel-concrete composite slab composite beam structure as Figures 1-9 shown, which includes a steel beam 2, a steel plate shear connector 6, a horizontal additional reinforcement 1, a joint reinforcement 9, a precast concrete floor slab, a post-cast concrete layer 5, etc.

[0030] The steel beam 2 uses an H-shaped steel beam or a box-shaped steel beam. The upper end of the steel plate shear connector 6 is provided with a plurality of U-shaped card slots at intervals for placing the horizontal additional reinforcement 1, and is welded to the upper flange of the steel beam 2 along the center line of the steel beam 2.

[0031] The precast concrete floor slab includes an end plate 3 with a dovetail groove opened on one side, an intermediate plate 4 with a dovetail groove opened through, and a joint reinforcement 9 with a bent end. The plate sides of the end plate 3 and the intermediate plate 4 are both flat surfaces without protruding beard bars. The end plate 3 and the intermediate plate 4 are closely joined. The intermediate plate 4 is placed between two adjacent end plates 3 to make the dovetail groove penetrate through the end plate - intermediate plate - end plate, and the end of the precast concrete floor slab is lapped on the upper flange of the steel beam 2. The joint reinforcement 9 is placed in the dovetail groove to connect the end plate 3 and the intermediate plate 4.

[0032] Each dovetail groove is distributed between two adjacent steel bars in the front-back direction at the bottom of the precast concrete floor slab, and the depth of the dovetail groove is ensured not to conflict with the steel bars in the left-right direction at the bottom of the precast concrete floor slab.

[0033] The post-cast concrete layer 5 includes post-cast concrete and surface layer steel bars. The post-cast concrete is poured on the upper surface of the precast concrete floor slab. The steel plate shear connector 6 with a U-shaped card slot and the horizontal additional reinforcement 1 are embedded in the post-cast concrete layer 5.

[0034] The steel plate shear connector 6 with a U-shaped card slot adopts a one-piece design, which is convenient for the positioning and placement of the horizontal additional reinforcement 1. The length is adjusted according to the length of the beam. A certain length is reserved at the end of the steel plate shear connector 6 and the end of the steel beam 2, and it is welded to the upper flange of the steel beam 2 along the center line of the steel beam 2.

[0035] The additional transverse reinforcement 1 is a key component to ensure the effective connection between the precast concrete base plate and the steel beam 2, and serves as the longitudinal shear reinforcement of the composite beam.

[0036] A dovetail groove, wider at the top and narrower at the bottom, is provided on the upper surface of the precast concrete base plate to enhance the combined effect of the post-cast concrete layer 5 and the precast concrete base plate. Adjacent precast base plates are closely joined, with joint reinforcement 9 placed in the dovetail grooves. Finally, the composite slab is formed by post-cast concrete.

[0037] Example 2: In this embodiment, the length of the precast concrete base plate resting on the steel beam is typically 40-50 mm. There is a distance between the end of the precast concrete base plate and the steel plate shear connector 6, so the precast concrete base plate does not directly contact the steel plate shear connector 6. This arrangement not only reduces the use of precast concrete base plates, but also allows post-cast concrete to be poured into the gap between the end of the precast concrete base plate and the steel plate shear connector 6 during concrete pouring, allowing the entire composite plate to fit together and interlock, enhancing the combined effect of the steel beam and composite plate.

[0038] Example 3: In this embodiment, elastic limit blocks are provided on the side walls of the U-shaped slot of the steel plate shear connector 6 to limit the upward movement of the transverse additional steel bars 1 during the subsequent pouring of concrete. A set of elastic limit blocks are installed on the front and rear side walls of each U-shaped slot. Each set of elastic limit blocks includes a rubber block 7 and a spring 8. The spring is a cylindrical compression spring, one end of which is welded to the side wall of the slot and the other end is connected to the rubber block 7. The opposite side of the two rubber blocks is sloped, which is convenient for the transverse additional steel bar 1 to be inserted. Moreover, the distance between the two rubber blocks 7 is smaller than the diameter of the transverse additional steel bar 1. The transverse additional steel bar 1 squeezes the rubber block 7 to both sides along the slope, so that the spring 8 is deformed and inserted into the slot. After the spring 8 recovers its deformation, the distance between the two rubber blocks 7 becomes smaller, and the transverse additional steel bar 1 is stuck in the U-shaped slot and cannot move upward.

[0039] Example 4: In this embodiment, a set of hinges are installed on each side wall of the dovetail groove, and the opening and closing angles of the hinges are 30 degrees or 45 degrees. The support axis of the hinge is located at the top of the dovetail groove. The two chain plates of the hinge have different widths. The long chain plate 10 is connected to the side wall of the dovetail groove, and the short chain plate 11 is suspended. Both the long chain plate 10 and the short chain plate 11 are processed with multiple through holes for connecting to the bottom concrete precast slab and the concrete post-casting layer 5 as a whole. The joint steel bar 9 squeezes the two opposite short chain plates 11, and the short chain plates 11 rotate along the support axis to both sides. The distance between the two short chain plates 11 increases, and the joint steel bar 9 is stuck in the dovetail groove. The short chain plates 11 return to a position close to each other under the action of elastic force, and the joint steel bar 9 is stuck in the dovetail groove to prevent the joint steel bar 9 from moving up.

[0040] Embodiment Five: In this embodiment, the hinge is only installed at the end of the dovetail groove of the end plate 3, and no hinge is provided in the dovetail groove of the intermediate plate 4. Such a setting can facilitate construction operations, prevent over-positioning of the joint reinforcement 9, and save the usage amount of the hinge.

[0041] Embodiment Six: The present invention also discloses an assembly method for the above composite beam structure, which is specifically as follows: Step 1: Process multiple U-shaped card slots at intervals on the upper end of the steel plate shear connector 6, and weld elastic limit blocks on the side walls of the U-shaped card slots; Step 2: Support the formwork - place the bottom plate steel bar mesh - place the dovetail groove formwork at the dovetail groove - install hinges on both sides of the dovetail groove formwork - pour concrete - remove the dovetail groove formwork after the concrete curing is completed; when pouring concrete, part of the concrete just flows into the through holes of the long link plate 10, and the long link plate 10 and the concrete are prefabricated into the intermediate plate 4 and the end plate 3 with dovetail grooves and hinges on the side walls of the dovetail grooves; Step 3: Weld the steel plate shear connector 6 above the steel beam 2, and correspondingly lap the intermediate plate 4 and the end plate 3 on the right-angle support platform formed by the steel plate shear connector 6 and the steel beam 2; Step 4: Snap the joint reinforcement 9 into the space between the two hinges of the dovetail groove, and snap the transverse additional reinforcement 1 into the U-shaped card slot; Step 5: Pour concrete above the intermediate plate 4, the end plate 3 and the steel plate shear connector 6. The concrete flows into the dovetail groove and the through holes of the short link plate 11 to form a post-cast concrete layer 5 connected to the precast concrete bottom plate as a whole.

[0042] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent replacements or changes, and should be covered by the protection scope of the present invention.

Claims

1. A steel-concrete composite slab composite beam structure, characterized in that, It includes steel plate shear connectors (6), and a set of concrete precast bottom plates are symmetrically arranged on the left and right sides of the steel plate shear connectors (6), and a concrete post-cast layer (5) is arranged above the concrete precast bottom plates; Multiple grooves are arranged at intervals at the upper end of the steel plate shear connectors (6), and transverse additional steel bars (1) are clamped in the grooves, and the transverse additional steel bars (1) extend to the lower part of the concrete post-cast layer (5) on the left and right sides respectively; Each set of concrete precast bottom plates includes an intermediate plate (4) and end plates (3) located at the front and rear ends of the intermediate plate. Multiple dovetail grooves running front and back are arranged on the upper surfaces of the intermediate plate (4) and the end plates (3), and multiple joint bars (9) are jointly clamped in the coaxial dovetail grooves.

2. A steel-concrete composite slab composite beam structure according to claim 1, characterized in that, Elastic limit blocks for restricting the upward movement of the transverse additional steel bars (1) are arranged on the side walls of the grooves.

3. A steel-concrete composite slab composite beam structure according to claim 2, characterized in that, The elastic limit blocks include a spring (8) and a rubber block (7) connected to each other, and one end of the spring (8) away from the rubber block (7) is connected to the side wall of the groove.

4. A steel-concrete composite slab composite beam structure according to claim 2, characterized in that, Hinges are arranged on the side walls of the dovetail grooves. The support shafts of the hinges are located at the top of the dovetail grooves. The widths of the two link plates of the hinges are different. Among them, the long link plate (10) is connected to the side wall of the dovetail groove, and the short link plate (11) is suspended.

5. A steel-concrete composite slab composite beam structure according to claim 4, characterized in that, The hinges are installed at the ends of the dovetail grooves on the end plates (3). The hinges are 30-degree hinges or 45-degree hinges, and at least one through hole is arranged on the link plates.

6. A steel-concrete composite slab composite beam structure according to claim 5, characterized in that, The grooves are U-shaped grooves. Two groups of elastic limit blocks are symmetrically arranged in each groove, and two groups of hinges are symmetrically arranged in each dovetail groove.

7. A steel-concrete composite slab composite beam structure according to claim 1, characterized in that A set distance is provided between the ends of the concrete precast bottom plates and the steel plate shear connectors (6).

8. A steel-concrete composite slab composite beam structure according to claim 1, characterized in that A steel beam (2) is arranged below the steel plate shear connectors (6), and the concrete precast bottom plates are lapped above the steel beam (2).

9. A steel-concrete composite slab composite beam structure according to claim 1, characterized in that, The dovetail grooves on the intermediate plate (4) are of a structure that is transparent from front to back, and the dovetail grooves on the end plates (3) are of a structure with one end open and the other end closed near the intermediate plate (4).

10. An assembly method for the steel-concrete composite slab composite beam structure according to any one of claims 1 to 9 is as follows: Step 1: Process multiple mutually parallel grooves at intervals at the upper end of the steel plate shear connectors (6), and install elastic limit blocks on the side walls of the grooves; Step 2: Precast an intermediate plate (4) and end plates (3) with dovetail grooves and hinges on the side walls of the dovetail grooves; Step 3: Weld the steel plate shear connectors (6) above the steel beam (2), and correspondingly lap the intermediate plate (4) and the end plates (3) on the right-angle support platform composed of the steel plate shear connectors (6) and the steel beam (2); Step 4: Align the intermediate plate (4) and the end plates (3) laterally, insert the joint bars (9) between the two hinges of the dovetail grooves, and insert the transverse additional steel bars (1) into the grooves; Step 5: Pour concrete above the intermediate plate (4), the end plates (3) and the steel plate shear connectors (6) to form a concrete post-cast layer (5).

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