Full-prefabricated detachable steel-concrete composite beam structure and construction method

Abstract

The invention discloses a full-prefabricated detachable steel-concrete composite beam structure and a construction method, and belongs to the technical field of structural engineering. The composite beam structure comprises a prefabricated concrete plate, an embedded part, a detachable shear connecting piece and an I-shaped steel beam, the embedded part and the prefabricated concrete plate are integrally poured, the I-shaped steel beam is arranged on the lower surface of the embedded part, and the I-shaped steel beam and the embedded part are fixed through the detachable shear connecting piece. The method has the beneficial effects that the embedded part is arranged in the precast concrete slab, so that the bolt pre-tightening force loss caused by concrete creep in the long-term process can be effectively avoided; before relative slippage occurs between the I-shaped steel beam and the precast concrete plank, the transmission of shearing force depends on static friction force; the I-shaped steel beam is in direct contact with the embedded part, and the friction behavior between steel is more controllable compared with the friction behavior between the steel and a concrete material, so that the stability and reliability of connection are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of structural engineering, and in particular relates to a fully prefabricated detachable steel-concrete composite beam structure and a construction method. Background Art

[0002] Steel-concrete composite beams connect steel beams and reinforced concrete slabs into a whole through shear connectors, giving full play to the high tensile properties of steel and the high compressive properties of concrete. They are widely used in bridges, buildings, industrial structures and other fields. Steel-concrete composite beam structures generally use welded studs as shear connectors, which are difficult to disassemble and difficult to recycle building materials. Therefore, it is particularly important to make steel-concrete composite beams removable throughout their life cycle, which has broad application prospects. The key lies in achieving the removability of shear connectors.

[0003] In recent years, bolts have replaced welded studs as shear connectors in some composite beam components, which can realize the disassembly and separation of steel beams and concrete slabs. Bolted detachable shear connectors usually require installation holes to be reserved on the steel beam flange and concrete slab, and the hole position accuracy requirements are high, which makes it difficult to dock the holes during assembly. In addition, bolted detachable shear connectors usually act directly on the concrete slab, and the concrete is easily subjected to excessive local compressive stress. The long-term creep of concrete has an impact on the bolt preload, which in turn affects the overall performance of the composite beam. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide a fully prefabricated detachable steel-concrete composite beam structure and construction method, which can effectively avoid the loss of bolt preload caused by concrete creep in a long-term process by arranging embedded parts in the precast concrete slab; in addition, before relative slip occurs between the I-shaped steel beam and the precast concrete slab, the transmission of shear force depends on static friction; the I-shaped steel beam is in direct contact with the embedded parts, and the friction behavior between the steels is more controllable than the friction behavior between the steels and the concrete material, thereby ensuring the stability and reliability of the connection, thereby solving at least one technical problem involved in the background technology.

[0005] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0006] The embodiment of the present invention provides a fully prefabricated detachable steel-concrete composite beam structure, including a prefabricated concrete slab, an embedded part, a detachable shear connector and an I-shaped steel beam, wherein the embedded part includes a bottom plate arranged at the bottom of the prefabricated concrete slab, an inverted tapered steel pipe arranged on the upper surface of the bottom plate and penetrating the prefabricated concrete slab, and an overhanging section arranged on the lower surface of the bottom plate; the I-shaped steel beam is arranged on the lower surface of the bottom plate, and the I-shaped steel beam includes an upper flange abutting against the bottom plate, and the upper flange is penetrated by a reserved hole matched with the overhanging section; the detachable shear connector includes a bolt, an arc-shaped gasket, a pressure head, a gasket and a nut, and the pressure head part One part abuts against the edge of the lower surface of the upper flange, and the other part abuts against the lower surface of the base plate; the arc-shaped gasket is arranged at the bottom of the pressure head, and the bottom of the pressure head is provided with a groove with a certain curvature and used to accommodate the arc-shaped gasket, the arc-shaped surface of the arc-shaped gasket is arranged opposite to the groove and the curvature of the arc-shaped surface is slightly larger than the curvature of the groove, and the overall height of the arc-shaped gasket is larger than the depth of the groove; the screw rod of the bolt passes through the arc-shaped gasket, the pressure head, the base plate and the inverted tapered steel pipe in sequence, and the tail end of the screw rod is exposed from the inverted tapered steel pipe; the gasket sleeve is provided with the tail end of the screw rod and is tightened and fixed by the nut.

[0007] Optionally, the embedded part further includes a pad arranged at an end of the inverted tapered steel pipe away from the bottom plate, and the pad abuts against an upper surface of the precast concrete slab.

[0008] Optionally, the embedded parts are made of steel, and the pad, the inverted cone steel pipe, the bottom plate and the extending section are formed into one piece by welding.

[0009] Optionally, the upper surface of the pad is flush with the upper surface of the precast concrete slab, and the lower surface of the base plate is flush with the lower surface of the precast concrete slab.

[0010] Optionally, the bolts are high-strength bolts and the washers are flat washers.

[0011] Optionally, the surface of the pressure head in contact with the upper flange is provided with convex teeth for increasing friction.

[0012] Optionally, the surface where the pressure head contacts the upper flange has a certain inclination angle, and the surface where the pressure head contacts the lower surface of the bottom plate is an arc-shaped surface.

[0013] Optionally, the precast concrete slab and the embedded parts are cast integrally.

[0014] The present invention also provides a construction method of the fully prefabricated detachable steel-concrete composite beam structure, the method comprising the following steps:

[0015] Step 1: welding the backing plate, the inverted tapered steel pipe, the bottom plate and the extension section to form an embedded part through a welding process;

[0016] Step 2, starting from the bottom plate, pouring concrete upwards until it is flush with the upper surface of the pad, and after the concrete curing is completed, an integrally arranged precast concrete plate and embedded parts are obtained;

[0017] Step 3: insert the extension section into the reserved hole on the I-shaped steel beam, and then pass the screw of the bolt through the arc-shaped gasket, the pressure head, the bottom plate, the inverted tapered steel pipe, the pad, the gasket and the nut from bottom to top. At this time, the pressure head should clamp the upper flange of the I-shaped steel beam from the side, and the convex teeth of the pressure head should abut against the lower surface of the upper flange, and the arc surface of the pressure head should abut against the lower surface of the bottom plate;

[0018] Step 4: Use a torque wrench to tighten the nut and apply pre-tightening force to the bolt, so that the bolt transmits pressure to the pressure head, thereby clamping the I-shaped steel beam and the precast concrete slab to achieve a detachable connection of the composite beam.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The detachable shear connector provided by the present invention adopts the side clamping of the I-shaped steel beam. By applying a pre-tightening force to the bolts, the pressure head can effectively press the I-shaped steel beam and the precast concrete slab, and the friction force of the sliding interface is relied on to achieve effective transmission of shear force. It has the advantages of large initial stiffness and easy installation and disassembly, which is conducive to the recycling and reuse of building materials.

[0021] (2) After the shear connector passes through the inverted tapered steel tube of the embedded part in the precast concrete slab, it only needs to clamp the upper flange of the I-shaped steel beam from the side, which makes the installation more flexible and effectively avoids the construction difficulty of the traditional bolt-type detachable shear connector that needs to be aligned and passed through the reserved holes of the concrete slab and the reserved holes of the steel beam at the same time.

[0022] (3) By setting embedded parts in the precast concrete slab, the detachable shear connector directly acts on the pad, conical steel pipe and bottom plate of the embedded parts, thereby reducing the local compressive stress of the precast concrete slab.

[0023] (4) The inverted tapered steel pipe of the embedded part has a certain taper from top to bottom to prevent the embedded part from being pulled out of the precast concrete slab during use.

[0024] (5) The extended section of the embedded part can be inserted into the reserved hole of the upper flange of the I-shaped steel beam, providing additional shear resistance and limiting effect after the precast concrete slab and the I-shaped steel beam slide relative to each other.

[0025] (6) All components of the embedded parts are made of steel, which has a more stable long-term performance than concrete materials and can effectively avoid the loss of bolt preload caused by concrete creep in the long term. In addition, before relative slip occurs between the I-beam and the precast concrete slab, the transmission of shear force depends on static friction. The I-beam and the embedded parts are in direct contact, and the friction behavior between steel is more controllable than the friction behavior between steel and concrete materials, thereby ensuring the stability and reliability of the connection.

[0026] (7) The inverted tapered steel pipe can also be used as a template for the reserved holes in the precast concrete slab, saving the construction steps of supporting the formwork and demoulding during the production of the reserved holes in the precast concrete slab.

[0027] (8) The bottom of the pressure head is provided with a groove with a certain curvature for accommodating the arc-shaped gasket, so as to ensure that when the screw rod of the bolt is tilted, the arc-shaped gasket can rotate freely in the tilting direction, thereby ensuring that the head of the bolt always acts vertically on the arc-shaped gasket.

[0028] (9) The surface where the pressure head contacts the upper flange has a certain inclination angle, and the surface where the pressure head contacts the lower surface of the base plate is an arc surface, which can expand the adaptation range between the pressure head and the thickness of the upper flange of the I-shaped steel beam.

[0029] (10) The contact portion between the pressure head and the lower surface of the upper flange of the I-shaped steel beam is provided with convex teeth, which can effectively enhance the friction between the pressure head and the I-shaped steel beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0031] Figure 1 A schematic diagram of an exploded structure of a fully prefabricated detachable steel-concrete composite beam structure provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the three-dimensional structure of the embedded part provided in an embodiment of the present invention;

[0033] Figure 3 A schematic front view of the structure of the embedded part provided in an embodiment of the present invention;

[0034] Figure 4 A schematic front view of the structure of a precast concrete panel provided in an embodiment of the present invention;

[0035] Figure 5A schematic diagram of the three-dimensional structure of an I-shaped steel beam provided in an embodiment of the present invention;

[0036] Figure 6 A schematic front view of the structure of a fully prefabricated detachable steel-concrete composite beam provided in an embodiment of the present invention;

[0037] Figure 7 A schematic diagram of the three-dimensional structure of a detachable shear connector provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0040] See also Figure 1 As shown, an embodiment of the present invention provides a fully prefabricated detachable steel-concrete composite beam structure, including a prefabricated concrete slab 1, embedded parts 2, detachable shear connectors 3 and an I-shaped steel beam 4. The prefabricated concrete slab 1 and the embedded parts 2 are integrally cast and formed. In this way, the prefabricated concrete slab 1 is provided with the embedded parts 2 during the prefabrication process, so that the detachable shear connectors 3 directly act on the embedded parts 2, thereby reducing the local compressive stress of the prefabricated concrete slab 1.

[0041] Combination Figure 2 and Figure 3 As shown, the embedded part 2 includes a pad 21 arranged on the top surface of the precast concrete slab 1, a bottom plate 23 arranged on the bottom surface of the precast concrete slab 1, an inverted tapered steel pipe 22 arranged on the upper surface of the bottom plate 23 and penetrating the precast concrete slab 1, and an overhanging section 24 arranged on the lower surface of the bottom plate 23. The pad 21 is arranged at one end of the inverted tapered steel pipe 22 away from the bottom plate 23.

[0042] The embedded part 2 is made of steel, and the pad 21, the inverted tapered steel pipe 22, the bottom plate 23 and the extension section 24 are formed into one piece by welding. Therefore, the long-term performance of the embedded part 2 is more stable than that of concrete materials, and can effectively avoid the loss of bolt preload caused by concrete creep in the long term; in addition, before relative slip occurs between the I-shaped steel beam 4 and the precast concrete slab 1, the transmission of shear force depends on static friction; the I-shaped steel beam 4 is in direct contact with the embedded part 2, and the friction behavior between steels is more controllable than the friction behavior between steel and concrete materials, thereby ensuring the stability and reliability of the connection.

[0043] The upper surface of the pad 21 is flush with the upper surface of the precast concrete slab 1, and the lower surface of the bottom plate 23 is flush with the lower surface of the precast concrete slab 1. Figure 4 As shown, recessed portions may be provided on the upper and lower surfaces of the precast concrete slab 1 to achieve flushness.

[0044] The inverted tapered steel pipe 22 has a certain taper from top to bottom to prevent the embedded part 2 from being pulled out of the precast concrete slab 1 during use. Moreover, the inverted tapered steel pipe 22 can also serve as a template for the reserved holes in the precast concrete slab 1, saving construction steps such as formwork and demoulding during the production of the reserved holes in the precast concrete slab.

[0045] Recombination Figure 5 As shown, the I-shaped steel beam 4 is arranged on the lower surface of the base plate 23, and the I-shaped steel beam 4 includes an upper flange 41 abutting against the base plate 23, and the upper flange 41 is penetrated by a reserved hole 411 cooperating with the extended section 24. In this way, the reserved hole 411 cooperates with the extended section 24, so that the hole alignment problem in the construction process of the traditional bolt-type detachable shear connector can be effectively solved, and it can also provide additional shear resistance and limiting effect after the precast concrete slab 1 and the I-shaped steel beam 4 slide relative to each other.

[0046] Recombination Figure 6 and Figure 7 As shown, the detachable shear connector 3 includes a bolt 31 , an arc-shaped gasket 32 ​​, a pressure head 33 , a gasket 34 and a nut 35 .

[0047] The bolt 31 is a high-strength bolt, and the gasket 34 is a flat gasket.

[0048] A portion of the pressing head 33 abuts against the lower surface edge of the upper flange 41 , and another portion abuts against the lower surface of the bottom plate 23 .

[0049] The arc-shaped gasket 32 ​​is arranged at the bottom of the pressure head 33. The bottom of the pressure head 33 is provided with a groove (not shown) with a certain curvature and used to accommodate the arc-shaped gasket 32. The arc-shaped surface 321 of the arc-shaped gasket 32 ​​is arranged opposite to the groove and the curvature of the arc-shaped surface 321 is slightly larger than the curvature of the groove, and the overall height of the arc-shaped gasket 32 ​​is larger than the depth of the groove. In this way, it can be ensured that when the screw rod 311 of the bolt 31 is tilted, the arc-shaped gasket 32 ​​can rotate freely in the tilting direction, thereby ensuring that the head of the bolt 31 always acts vertically on the arc-shaped gasket 32.

[0050] The screw rod 311 of the bolt 31 passes through the arc-shaped gasket 32, the pressure head 33, the bottom plate 23 and the inverted tapered steel pipe 22 in sequence, and the tail end of the screw rod 311 is exposed from the inverted tapered steel pipe 22. The gasket 34 is sleeved with the tail end of the screw rod 311 and is tightened and fixed by the nut 35. By applying a pre-tightening force to the bolt 31, the pressure head 33 can effectively press the I-shaped steel beam 4 and the precast concrete slab 1, and the friction force of the sliding interface is relied on to achieve effective transmission of shear force. It has the advantages of large initial stiffness, easy installation and disassembly, etc., and is conducive to the recycling and reuse of building materials.

[0051] In general, after the shear connector 3 passes through the inverted tapered steel pipe 22 of the embedded part 2 in the precast concrete slab 1, it only needs to clamp the upper flange 41 of the I-shaped steel beam 4 from the side, which has higher installation flexibility and effectively avoids the construction difficulty of traditional bolt-type detachable shear connectors that need to be aligned and passed through the reserved holes of the concrete slab and the reserved holes of the steel beam at the same time.

[0052] Furthermore, the surface of the pressing head 33 in contact with the upper flange 41 is provided with convex teeth 331 for increasing friction, which can effectively enhance the friction between the pressing head 33 and the I-shaped steel beam 4.

[0053] The surface where the pressure head 33 contacts the upper flange 41 has a certain inclination angle, and the surface where the pressure head 33 contacts the lower surface of the base plate 23 is an arc surface, which can expand the adaptation range between the pressure head 33 and the thickness of the upper flange 41 of the I-shaped steel beam 4.

[0054] The present invention also provides a construction method of the fully prefabricated detachable steel-concrete composite beam structure, the method comprising the following steps:

[0055] Step 1: weld the backing plate 21, the inverted tapered steel pipe 22, the bottom plate 23 and the extension section 24 through a welding process to form the embedded part 2;

[0056] Step 2: starting from the bottom plate 23, pouring concrete upward until it is flush with the upper surface of the pad 21, and after the concrete curing is completed, an integrally arranged precast concrete slab 1 and embedded parts 2 are obtained;

[0057] Step 3: insert the extension section 24 into the reserved hole 411 on the I-shaped steel beam 4, and then pass the screw 311 of the bolt 31 through the arc-shaped gasket 32, the pressure head 33, the bottom plate 23, the inverted tapered steel pipe 22, the pad 21, the gasket 34 and the nut 35 from bottom to top. At this time, the pressure head 33 should clamp the upper flange 41 of the I-shaped steel beam 4 from the side, and the convex teeth 331 of the pressure head 33 abut against the lower surface of the upper flange 41, and the arc surface of the pressure head 33 abuts against the lower surface of the bottom plate 23;

[0058] Step 4: Use a torque wrench to tighten the nut 35 and apply a pre-tightening force to the bolt 31, so that the bolt 31 transmits pressure to the pressure head 33, thereby clamping the I-shaped steel beam 4 and the precast concrete slab 1 to achieve a detachable connection of the composite beam.

[0059] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0060] In addition, it should be noted that the scope of the methods and systems in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0061] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A fully prefabricated detachable steel-concrete composite beam structure, characterized in that: The invention comprises a precast concrete slab, an embedded part, a detachable shear connector and an I-shaped steel beam, wherein the embedded part comprises a bottom plate arranged at the bottom of the precast concrete slab, an inverted tapered steel pipe arranged on the upper surface of the bottom plate and penetrating the precast concrete slab, and an overhanging section arranged on the lower surface of the bottom plate; the I-shaped steel beam is arranged on the lower surface of the bottom plate, and the I-shaped steel beam comprises an upper flange abutting against the bottom plate, and the upper flange is penetrated with a reserved hole matched with the overhanging section; the detachable shear connector comprises a bolt, an arc-shaped gasket, a pressure head, a gasket and a nut, and a part of the pressure head abuts against the lower surface edge of the upper flange The arc-shaped gasket is arranged at the bottom of the pressure head, and the bottom of the pressure head is provided with a groove with a certain curvature and used to accommodate the arc-shaped gasket, the arc-shaped surface of the arc-shaped gasket is arranged opposite to the groove and the curvature of the arc-shaped surface is slightly larger than the curvature of the groove, and the overall height of the arc-shaped gasket is larger than the depth of the groove; the screw rod of the bolt passes through the arc-shaped gasket, the pressure head, the bottom plate and the inverted conical steel pipe in sequence, and the tail end of the screw rod is exposed from the inverted conical steel pipe; the gasket sleeve is provided with the tail end of the screw rod and is tightened and fixed by the nut.

2. The fully prefabricated detachable steel-concrete composite beam structure according to claim 1 is characterized in that: The embedded part also includes a pad arranged at one end of the inverted tapered steel pipe away from the bottom plate, and the pad abuts against the upper surface of the precast concrete slab.

3. The fully prefabricated detachable steel-concrete composite beam structure according to claim 2 is characterized in that: The embedded parts are made of steel, and the backing plate, the inverted tapered steel pipe, the bottom plate and the extended section are formed into one piece by welding.

4. The fully prefabricated detachable steel-concrete composite beam structure according to claim 2, characterized in that: The upper surface of the backing plate is flush with the upper surface of the precast concrete slab, and the lower surface of the bottom plate is flush with the lower surface of the precast concrete slab.

5. The fully prefabricated detachable steel-concrete composite beam structure according to claim 1, characterized in that: The bolts are high-strength bolts, and the washers are flat washers.

6. The fully prefabricated detachable steel-concrete composite beam structure according to claim 5, characterized in that: The surface of the pressure head in contact with the upper flange is provided with convex teeth for increasing friction.

7. The fully prefabricated detachable steel-concrete composite beam structure according to claim 1 or 6, characterized in that: The surface where the pressure head contacts the upper flange has a certain inclination angle, and the surface where the pressure head contacts the lower surface of the bottom plate is an arc surface.

8. The fully prefabricated detachable steel-concrete composite beam structure according to claim 1, characterized in that: The precast concrete slab and the embedded parts are integrally cast and formed.

9. A construction method for a fully prefabricated detachable steel-concrete composite beam structure as claimed in any one of claims 1 to 8, characterized in that: The method comprises the following steps: Step 1: welding the backing plate, the inverted tapered steel pipe, the bottom plate and the extension section to form an embedded part through a welding process; Step 2, starting from the bottom plate, pouring concrete upwards until it is flush with the upper surface of the pad, and after the concrete curing is completed, an integrally arranged precast concrete plate and embedded parts are obtained; Step 3: insert the extension section into the reserved hole on the I-shaped steel beam, and then pass the screw of the bolt through the arc-shaped gasket, the pressure head, the bottom plate, the inverted tapered steel pipe, the pad, the gasket and the nut from bottom to top. At this time, the pressure head should clamp the upper flange of the I-shaped steel beam from the side, and the convex teeth of the pressure head should abut against the lower surface of the upper flange, and the arc surface of the pressure head should abut against the lower surface of the bottom plate; Step 4: Use a torque wrench to tighten the nut and apply pre-tightening force to the bolt, so that the bolt transmits pressure to the pressure head, thereby clamping the I-shaped steel beam and the precast concrete slab to achieve a detachable connection of the composite beam.

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