A new type of shear member composite beam and its construction method

Abstract

The present invention provides a novel shear member composite beam, comprising a concrete slab (1), stirrups (2), a shear member (3) and a steel beam (4), wherein the steel beam (4) is arranged on the lower surface of the concrete slab (1), a shear member (3) is arranged inside the concrete slab (1) near the lower bottom surface, the stirrups (2) are vertically arranged inside the concrete slab (1), and the shear member (3) is welded to the contact position of the stirrups (2). The novel shear member composite beam described in the present invention realizes the precise docking of the reserved hole position of the concrete slab with the steel beam connector, ensures the overall performance of the concrete slab after the reserved hole position, gives full play to the role of the shear connector, and connects the steel structure and the concrete structure to work together as a whole.

Description

Technical Field

[0001] The invention relates to the field of bridge construction, and in particular to a composite beam. Background Art

[0002] Steel-concrete composite structure is a structural form that uses shear connectors to form a steel structure and a concrete structure to work together as a whole. Shear connectors are the key to the mechanical performance of steel-concrete composite structures. This structural form can give full play to the mechanical properties of steel and concrete materials, and has the advantages of high bearing capacity, high rigidity, low deadweight, good stability and convenient construction. It is widely used in engineering fields such as bridges, building structures, and pipe galleries.

[0003] With the development of engineering technology, people have higher and higher requirements for construction technology and engineering quality, and the application of prefabricated construction technology has become more and more extensive. Structural prefabricated construction can realize the completion of all components in the factory, which can improve the quality of components and reduce the amount of component materials, which is of great significance for building energy conservation. Prefabricated construction can greatly reduce the workload and time of on-site construction, and plays an important role in projects with strict construction period requirements and harsh on-site construction environment.

[0004] The problem of how to set up shear connectors is faced in the prefabricated construction of steel-concrete composite structures. The most widely used bolt connectors require multi-point coordination. The reserved points in the precast concrete slab will change position due to the shrinkage of the concrete during the hardening process, and it is impossible to complete the multi-point matching during the installation process. Since the perforated steel plate connector continuously penetrates along the longitudinal direction of the beam, it is impossible to reserve a longitudinal penetration seam in the precast concrete slab, and it is impossible to achieve an effective connection between the perforated steel plate connector and the concrete precast slab. In the existing separate bolt group connection method, large holes are reserved in the concrete precast slab, and the longitudinal and transverse steel bars between the reserved holes are all cut off, which seriously affects the integrity of the concrete slab. In addition, the bolt group and the precast concrete slab are only transmitted through the post-cast concrete. The bolt connector cannot fully play its role in connecting the steel structure and the concrete structure into a whole.

[0005] The assembly construction of steel-concrete composite structures requires solving three problems of connectors. First, how to accurately connect the reserved holes in the precast concrete slab with the bolt connectors on the steel structure. Second, how to reduce the reserved holes in the precast concrete slab and reduce their impact on the integrity of the precast concrete slab. Third, how to give full play to the role of shear connectors to connect the steel structure and concrete structure into a whole.

[0006] Patent CN201120487335 discloses a shear member for fastening concrete in bridge construction, including a shear member body composed of a plurality of interconnected shear member units, wherein the shear member units include a support plate, mounting plates are provided at both ends of the support plate, a plurality of groups of through holes are provided on the mounting plate, and support columns are provided between each group of through holes.

[0007] Although this patent uses shear member units connected to each other to form a whole, its supporting plate structure is relatively complex, resulting in a relatively complex manufacturing process. At the same time, the shear member unit setting method results in the shear members forming a whole, but has a greater impact on the integrity of the concrete.

[0008] A composite beam is now needed in which a reserved hole in a precast concrete slab can be precisely connected with a bolt connector on a steel structure; the reserved hole in the concrete slab is relatively small; and the steel structure and the concrete structure are connected to form a whole. Summary of the invention

[0009] In order to solve the problem in the prior art of the docking accuracy of the reserved holes in the concrete slab and the bolt connectors on the steel structure, reduce the impact on the integrity of the precast concrete slab, and give full play to the role of the shear connector, the present invention provides a new type of shear connector composite beam, which has high concrete slab integrity, small reserved holes, and is easy to accurately dock, thereby solving the above problems.

[0010] The present invention provides a novel shear member composite beam, comprising a concrete slab, stirrups, a shear member and a steel beam, wherein the steel beam is arranged on the lower surface of the concrete slab, a shear member is arranged inside the concrete slab near the lower bottom surface, the stirrups are vertically arranged inside the concrete slab, and the shear member is welded at the contact position with the stirrups.

[0011] The novel shear member composite beam described in the present invention, as a preferred mode, the shear member includes a pin steel bar, a perforated steel plate, an embedded perforated steel plate, the perforated steel plate is provided with a mounting hole, the perforated steel plate is vertically arranged on the upper surface of the steel beam, the pin steel plate is arranged in the mounting hole, the surface of the embedded perforated steel plate is provided with a through hole, the perforated steel plate is arranged in the through hole, and the embedded perforated steel plate is embedded in the bottom surface of the concrete structure. Both ends of the embedded perforated steel plate should be aligned with the top of the formwork to prevent the position of the embedded steel plate from changing during the concrete pouring process and failing to match and install with the pre-designed connector.

[0012] A novel shear member composite beam described in the present invention, as a preferred embodiment, the stirrups include disconnected stirrups and ordinary stirrups, the disconnected stirrups are evenly arranged in the vertical plane where the through holes of the embedded perforated steel plate are located, the two ends of the disconnected stirrups are arranged on the bottom surfaces on both sides of the through holes of the embedded perforated steel plate, and the ordinary stirrups are evenly arranged in the vertical planes on both sides of the through holes of the embedded perforated steel plate.

[0013] By burying the pin bolt steel bar installation plate in the concrete structure, the docking accuracy of the hole position of the shear connector is improved; the pin bolt steel bar and the pin bolt steel bar installation plate are used to achieve a simple, fast and reliable connection. The perforated steel plate is set with a reserved hole at the designed position, and the perforated steel plate is installed with its two ends flush with the template to ensure that the position does not change during the concrete pouring process, so as to achieve accurate docking of the shear connector hole position. After the perforated steel plate is installed in the concrete structure, ordinary stirrups and disconnected stirrups are laid, and they are welded to the embedded perforated steel plate. The perforated steel plate can replace the longitudinal steel bar at this position, avoiding the longitudinal steel bar at this position from being disconnected due to the reserved holes, thereby improving the integrity of the structure.

[0014] The method of connecting the connector is that after the concrete slab and the steel structure are prefabricated, the through-hole positions of the perforated steel plate are connected, and then the pin steel rod is inserted into the pin steel rod installation plate to complete the reliable fixed connection of the shear connector.

[0015] Both reserved holes on the pin steel rod mounting plate and the perforated steel plate are considered to be appropriately enlarged to take into account the shrinkage of concrete and various errors.

[0016] The novel shear member composite beam of the present invention is preferably welded with the embedded perforated steel plate and stirrups.

[0017] In the novel shear member composite beam of the present invention, as a preferred embodiment, the perforated steel plate is arranged along the longitudinal or transverse direction of the steel beam. The pin-bolt steel column connecting plate can also be arranged along the transverse direction of the beam to improve the transverse shear resistance. The pin-bolt steel column connecting plate can be arranged along the longitudinal direction of the beam to improve the longitudinal shear resistance.

[0018] A novel shear member composite beam described in the present invention is, as a preferred embodiment, a pin steel rod includes a first frustum, a second frustum, a cylindrical connecting portion, the first frustum and the second frustum are coaxial with the cylindrical connecting portion, the lower bottom surfaces of the first frustum and the second frustum are arranged on the two bottom surfaces of the cylindrical connecting portion, and the area of ​​the lower bottom surfaces of the first frustum and the second frustum is ≤ the area of ​​the bottom surface of the cylindrical connecting portion.

[0019] The shuttle-shaped pin steel rod is used to facilitate positioning during splicing and improve splicing efficiency.

[0020] In the novel shear member composite beam described in the present invention, as a preferred embodiment, the pin steel rod and the mounting hole are in interference fit.

[0021] When opening a hole, an enlargement of 1 to 2 mm should be considered to take into account the influence of various errors.

[0022] A novel shear member composite beam described in the present invention is, as a preferred embodiment, a concrete slab comprising a concrete slab body and high-performance fiber concrete. The concrete body is a plate-type, and the concrete body is provided with a reserved hole, which is a countersunk hole. The reserved hole is arranged at the opposite end of the embedded perforated steel plate, and a through hole with the same size as the vertical position of the installation hole is arranged at the bottom of the reserved hole. A shear member is assembled through the through hole in the reserved hole, and the high-performance fiber concrete fills the reserved hole.

[0023] Considering the convenience of on-site construction, self-compacting, steam-free, micro-expanding ultra-high performance fiber concrete was selected.

[0024] The stirrups include disconnected stirrups connected to the shear connectors and ordinary stirrups not connected to the shear connectors. Disconnected stirrups are provided at positions where perforated steel plates are provided on the orthographic projection surface, and ordinary stirrups are provided at positions where no perforated steel plates are provided on the orthographic projection surface.

[0025] The present invention provides a novel shear member composite beam construction method, comprising the following steps:

[0026] S1. Make pin steel rod;

[0027] S2. Make steel beams and perforated steel plates, and weld the perforated steel plates to the top surface of the steel beams;

[0028] S3. Make a concrete slab with embedded perforated steel plate;

[0029] S4. Perform on-site assembly, butt-join and assemble the steel structure perforated steel plate with the reserved hole of the concrete slab; insert the pin steel rod into the steel beam perforated steel plate through the reserved hole of the concrete slab and the opposite end of the pre-embedded perforated steel plate;

[0030] S5. Pour self-compacting, steam-free, micro-expanding ultra-high performance fiber concrete into the reserved holes.

[0031] The novel shear member composite beam construction method of the present invention, as a preferred embodiment, step S3 specifically includes:

[0032] S31. Perform prefabricated reinforced concrete structure formwork support, lay perforated steel plates, lay transverse common stirrups and disconnected stirrups at reserved holes, and weld the transverse common stirrups and disconnected stirrups to the embedded perforated steel plates;

[0033] S32. Laying of longitudinal ordinary steel bars;

[0034] S33. Set a reserved hole at the location of the concrete slab connector;

[0035] S34. Pour concrete and remove the formwork after concrete curing is completed.

[0036] The beneficial effects of the present invention are as follows:

[0037] (1) By pre-embedding perforated steel plates in reinforced concrete structures, the impact of concrete shrinkage is greatly reduced, and precise positioning of the holes of the shear connectors of the prefabricated steel-concrete structure is achieved;

[0038] (2) The embedded perforated steel plates in the reinforced concrete structure are welded with ordinary stirrups and stirrups at the section opening, which avoids the impact of stirrup disconnection at the reserved hole position and improves the integrity of the structure;

[0039] (3) The embedded perforated steel plate in the reinforced concrete structure can replace the longitudinal steel bars at that location, thus avoiding the longitudinal steel bars at that location from being disconnected due to the reserved holes and improving the integrity of the structure;

[0040] (4) After the steel structure and the concrete structure are installed according to the reserved holes, the two are integrated by installing a pin steel rod in the perforated steel plate, which not only takes into account the convenience of construction but also ensures the effective connection of the connecting parts. The pin steel rod has a large rigidity and can effectively transmit the shear force between the steel structure and the concrete structure, while effectively resisting the lifting between the concrete structure and the steel structure;

[0041] (5) The perforated steel plates can be flexibly arranged in the longitudinal and transverse directions of the beams. The spacing between the steel plates, the length of the perforated steel plates, and the sizes of the openings and pin steel bars can all be flexibly arranged according to the actual needs of the prefabricated project, which has high applicability;

[0042] (6) After the steel structure and concrete structure are installed, self-compacting, steam-free, and slightly expanding ultra-high performance fiber concrete is poured in the reserved holes, taking into account the operability of on-site construction. Ultra-high performance fiber concrete and ordinary concrete are both cement-based materials and can be reliably bonded. Ultra-high performance fiber concrete has a dense material structure and good durability. It effectively transmits the force between the steel structure and the concrete structure while more effectively protecting the structure at the shear connection position. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the longitudinal section of the composite beam concrete slab;

[0044] Figure 2 It is the schematic diagram of shear member of composite beam;

[0045] Figure 3 This is a schematic diagram of the pin steel rod of the composite beam shear member;

[0046] Figure 4 It is a perspective diagram of the composite beam concrete slab;

[0047] Figure 5 The figure is a flow chart of the composite beam construction method.

[0048] Reference numerals:

[0049] 1. Concrete slab; 11. Concrete slab body; 12. High-performance fiber concrete; 2. Stirrups; 21. Ordinary stirrups; 22. Disconnected stirrups; 3. Shear members; 31. Pin steel rods; 311. First truncated cone; 312. Second truncated cone; 31. Column connection; 32. Perforated steel plate; 33. Embedded perforated steel plate; 4. Steel beam. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0051] Example 1

[0052] like Figure 1 As shown, a new type of shear member composite beam includes a concrete slab 1, stirrups 2, shear members 3 and steel beams 4. The steel beams 4 are arranged on the lower surface of the concrete slab 1. The shear members 3 are arranged inside the concrete slab 1 near the lower bottom surface. The stirrups 2 are vertically arranged inside the concrete slab 1. The shear members 3 are welded at the contact position with the stirrups 2.

[0053] like Figure 2 As shown, the shear member 3 includes a pin steel bar 31, a perforated steel plate 32, and a pre-embedded perforated steel plate 33. The perforated steel plate 32 is provided with a mounting hole, and the perforated steel plate 32 is vertically arranged on the upper surface of the steel beam 4. The pin steel bar 31 is arranged in the mounting hole, and the pre-embedded perforated steel plate 33 is provided with a through hole on the plate surface. The perforated steel plate 32 is arranged in the through hole, and the pre-embedded perforated steel plate 33 is embedded in the bottom surface of the concrete slab 1. The pin steel bar 31 and the mounting hole are interference fit. When opening the hole, an enlargement of 1 to 2 mm should be considered to take into account the influence of various errors. The two ends of the steel plate should be flush with the template to prevent the position of the embedded steel plate from changing during the concrete pouring process and failing to match and install with the pre-designed connector.

[0054] like Figure 3 As shown, the pin steel bar 31 includes a first truncated cone 311, a second truncated cone 312, and a cylindrical connecting portion 313. The first truncated cone 311, the second truncated cone 312 and the cylindrical connecting portion 313 are coaxial, the lower bottom surfaces of the first truncated cone 311 and the second truncated cone 312 are arranged on the two bottom surfaces of the cylindrical connecting portion 313, and the lower bottom surface area of ​​the first truncated cone 311 and the second truncated cone 312 is less than the bottom surface area of ​​the cylindrical connecting portion 313. The pin steel bar mounting plate 2 is made of steel plate, the diameter of its circular hole matches the base circle diameter of the cylindrical connecting portion of the pin steel bar, and its root is welded to the top of the steel structure.

[0055] like Figure 4As shown, the stirrups 2 include disconnected stirrups 22 and common stirrups 21. The disconnected stirrups 22 are evenly arranged on the vertical plane where the through hole of the embedded perforated steel plate 33 is located. The two ends of the disconnected stirrups 22 are arranged on the bottom surfaces on both sides of the through hole of the embedded perforated steel plate 33. The common stirrups 21 are evenly arranged on the vertical planes on both sides of the through hole of the embedded perforated steel plate 33. The embedded perforated steel plate 33 is welded to the stirrups 2. The perforated steel plate 32 is arranged longitudinally or transversely along the steel beam 4. The concrete slab 1 includes a concrete slab body 11 and high-performance fiber concrete 12. The concrete body 11 is a plate type. The concrete body 11 is provided with a reserved hole. The reserved hole is a countersunk hole. The reserved hole is arranged at the opposite end of the embedded perforated steel plate 33. A through hole of the same size as the vertical position of the installation hole is arranged at the bottom of the reserved hole. The shear member 3 assembled through the through hole is arranged in the reserved hole. The high-performance fiber concrete 12 fills the reserved hole. The size of the reserved hole is set unevenly relative to the position of the reserved hole. One reserved hole is the center line, one side is the full length of the pin steel rod, and the countersunk hole on one side is half the length of the countersunk hole. The depth of the countersunk hole is slightly greater than the height of the perforated steel plate 32, and the width is slightly greater than the width of the perforated steel plate 32. The spacing of the 31-length perforated steel plate 2, its own length, and the layout form can be designed and determined according to actual engineering needs.

[0056] like Figure 5 As shown, the novel shear member composite beam construction method comprises the following steps:

[0057] S1. Production of pin steel rod 31;

[0058] S2 production of steel beam 4 and perforated steel plate 32, perforated steel plate 32 welded to the top surface of the steel beam 4;

[0059] S3 production of concrete slab 1 embedded perforated steel plate 33;

[0060] S4 on-site assembly, the steel structure with holes 32 and the concrete slab 1 reserved hole for docking assembly; the pin steel rod 31 through the concrete slab 1 reserved hole and set the reverse end of the embedded perforated steel plate 33 inserted into the steel beam 4 perforated steel plate 32;

[0061] S5. Pour self-compacting, steam-free, micro-expanding ultra-high performance fiber concrete 12 into the reserved holes.

[0062] Step S3 specifically includes:

[0063] S31. Prefabricated reinforced concrete structure formwork support, laying perforated steel plate 32, laying transverse ordinary stirrups 21 and disconnected stirrups 22 at reserved holes, and welding the transverse ordinary stirrups 21 and disconnected stirrups 22 to the pre-buried perforated steel plate 33;

[0064] S32. Laying of longitudinal ordinary steel bars;

[0065] S33. Set a reserved hole at the location of the concrete slab connector;

[0066] S34. Pour concrete and remove the formwork after concrete curing is completed.

[0067] During the prefabrication of the concrete structure, a reserved hole matching the perforated steel plate 2 on the steel structure is reserved, and a reserved hole for installing the pin steel rod 1 into the reserved steel plate is reserved. Both reserved holes are considered to be appropriately enlarged to take into account the shrinkage of concrete and various errors.

[0068] The pre-buried steel plate with holes 33 is provided with reserved holes at the designed position, and the pre-buried steel plate with holes 33 is installed so that both ends thereof are flush with the top of the formwork to ensure that the position does not change during the concrete pouring process, and the holes of the shear connector are precisely docked. After the pre-buried steel plate with holes 33 is installed in the concrete structure, ordinary stirrups and disconnected stirrups are laid and welded to the pre-buried steel plate with holes 33.

[0069] After the concrete structure and the steel structure are prefabricated and connected according to the reserved holes, the pin steel rod 1 is inserted into the perforated steel plate 2 to complete the reliable fixed connection of the shear connector.

[0070] After the concrete structure and steel structure are assembled, self-compacting, steam-free, micro-expanding ultra-high performance fiber concrete is poured in the reserved holes, taking into account the construction convenience and connection reliability.

[0071] The shear connector and construction method for the assembled steel-concrete composite structure proposed in the present invention embeds a perforated steel plate 33 in the concrete structure and welds it with stirrups, and welds a perforated steel plate 2 on the top surface of the steel beam; after prefabrication in the factory, it is installed through the reserved hole position and fixed by the pin steel rod 1; after installation, self-compacting, steam-free, micro-expanding ultra-high performance fiber concrete is poured in the reserved hole. This connection method greatly improves the integrity of the assembled steel-concrete composite structure, effectively enhances the shear strength and rigidity of the assembled steel-concrete composite structure, and ensures the coordinated work of the steel structure and the concrete structure.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A new type of shear member composite beam, characterized in that: The concrete slab comprises a concrete slab (1), stirrups (2), a shear member (3) and a steel beam (4), wherein the steel beam (4) is arranged on the lower surface of the concrete slab (1), a shear member (3) is arranged inside the concrete slab (1) near the lower bottom surface, the stirrups (2) are arranged vertically inside the concrete slab (1), and the shear member (3) is welded to the contact position of the stirrups (2); The shear member (3) comprises a pin steel rod (31), a perforated steel plate (32), and a pre-buried perforated steel plate (33); the perforated steel plate (32) is provided with a mounting hole, and the pin steel rod (31) and the mounting hole are in interference fit; The concrete slab (1) comprises a concrete slab body (11) and high-performance fiber concrete (12); the concrete slab body (11) is a plate-type, the concrete slab body (11) is provided with a reserved hole, the reserved hole is a countersunk hole, the reserved hole is provided at the opposite end of the embedded perforated steel plate (33), a through hole with the same size as the vertical position of the mounting hole is provided at the bottom end of the reserved hole, the shear member (3) is assembled through the through hole, and the high-performance fiber concrete (12) fills the reserved hole.

2. A novel shear member composite beam according to claim 1, characterized in that: The perforated steel plate (32) is vertically arranged on the upper surface of the steel beam (4), the pin steel rod (31) is arranged in the mounting hole, the plate surface of the embedded perforated steel plate (33) is provided with a through hole, the perforated steel plate (32) is arranged in the through hole, and the embedded perforated steel plate (33) is embedded in the bottom surface of the concrete slab (1).

3. A novel shear member composite beam according to claim 2, characterized in that: The stirrups (2) include disconnected stirrups (22) and common stirrups (21); the disconnected stirrups (22) are evenly arranged on a vertical plane where the through hole of the pre-embedded perforated steel plate (33) is located; two ends of the disconnected stirrups (22) are arranged on the bottom surfaces on both sides of the through hole of the pre-embedded perforated steel plate (33); and the common stirrups (21) are evenly arranged on the vertical planes on both sides of the through hole of the pre-embedded perforated steel plate (33).

4. A novel shear member composite beam according to any one of claims 2 to 3, characterized in that: The embedded perforated steel plate (33) is welded to the stirrup (2).

5. The novel shear member composite beam according to claim 4 is characterized in that: The perforated steel plate (32) is arranged longitudinally or transversely along the steel beam (4).

6. The novel shear member composite beam according to claim 5 is characterized in that: The pin steel rod (31) comprises a first frustum (311), a second frustum (312), and a cylindrical connecting portion (313); the first frustum (311), the second frustum (312), and the cylindrical connecting portion (313) are coaxial; the lower surfaces of the first frustum (311) and the second frustum (312) are arranged on the two bottom surfaces of the cylindrical connecting portion (313); and the lower bottom surface areas of the first frustum (311) and the second frustum (312) are ≤ the bottom surface area of ​​the cylindrical connecting portion (313).

7. The construction method of a novel shear member composite beam according to claim 1 is characterized in that: The following steps are involved: S1. Making a pin steel rod (31); S2. Manufacturing a steel beam (4) and a perforated steel plate (32), wherein the perforated steel plate (32) is welded to the top surface of the steel beam (4); S3. Making a concrete slab (1), pre-embedded perforated steel plate (33); S4. On-site assembly, the steel structure perforated steel plate (32) and the reserved hole of the concrete slab (1) are docked and assembled; the pin steel rod (31) is inserted into the steel beam (4) perforated steel plate (32) through the reserved hole of the concrete slab (1) and the reverse end of the embedded perforated steel plate (33) is set; S5. Pour self-compacting, steam-free, micro-expanding ultra-high performance fiber concrete (12) into the reserved hole.

8. The construction method of a novel shear member composite beam according to claim 7 is characterized in that: Step S3 specifically includes: S31. Prefabricated reinforced concrete structure formwork support is performed, a perforated steel plate (32) is laid, transverse common stirrups (21) and disconnected stirrups (22) are laid at the reserved holes, and the transverse common stirrups (21) and the disconnected stirrups (22) are welded to the embedded perforated steel plate (33); S32. Laying of longitudinal ordinary steel bars; S33. Set a reserved hole at the location of the concrete slab connector; S34. Pour concrete and remove the formwork after concrete curing is completed.

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