In-line steel ladle wood-concrete composite beam

Abstract

This utility model relates to an embedded steel-clad wood-concrete composite beam, belonging to the field of composite beam technology. It includes a concrete slab with a trapezoidal groove extending along its length at the bottom. A wooden beam is positioned below the concrete slab, and the wooden beam has trapezoidal protrusions that mate with the groove, inserted into the groove. Several shear pins are arranged along the length of the wooden beam, fixing it to the upper part. An outer steel beam with a rectangular cavity is positioned below the concrete slab, and the wooden beam is embedded within this cavity. Two sets of barbed bolts are provided on the concrete slab, located on opposite sides of the trapezoidal groove. This utility model utilizes the compressive strength of steel and the tensile strength of wood in synergy, achieving efficient connection through mortise and tenon joints, pins, and bolts, enhancing overall load-bearing capacity and stability. It is suitable for large spans and negative bending moment areas, possessing excellent assembly adaptability and durability.

Description

Technical Field

[0001] This utility model relates to the field of composite beam technology, and in particular to an embedded steel-clad wood-concrete composite beam. Background Technology

[0002] In the civil engineering industry, traditional beams are mostly made of reinforced concrete slabs. Concrete, as a traditional building material, has advantages such as good moldability, durability, integrity, and high compressive strength. However, it also has significant drawbacks: high self-weight, low tensile strength, and susceptibility to cracking, while also having numerous adverse environmental impacts. Wood, on the other hand, has high tensile strength and is relatively lightweight. Connecting wooden beams or planks to concrete slabs to form a wood-concrete composite structure can greatly improve the strength and stiffness of the components, reduce the self-weight of the structural beams, and leverage the respective advantages of both wood and concrete, achieving full utilization of materials.

[0003] However, current composite beams have some problems. Although wood has high tensile strength, its compressive strength is relatively low. Furthermore, wood has a low modulus of elasticity, resulting in less than ideal bending resistance. Therefore, this limits the span and cross-section of wood-concrete composite beams, making them difficult to apply in large-span structures. Generally, in wood-concrete composite beams, the concrete is on the compression side, and the wood is on the tension side. However, in actual engineering projects, negative bending moment zones often appear at the supports. For composite beams in these negative bending moment zones, the wood beams are more susceptible to damage.

[0004] Patent CN202121298976 describes an inverted T-shaped steel-wood-concrete composite beam, comprising a reinforced concrete slab and an inverted T-shaped steel beam. The top of the web of the inverted T-shaped steel beam is fixedly embedded in the reinforced concrete slab. Wooden beams are filled in the groove between the inverted T-shaped steel beam and the bottom of the reinforced concrete slab. When this inverted T-shaped steel-wood-concrete composite beam bears load, the tensile force is mainly borne by the inverted T-shaped steel beam and the wooden beam, while the compressive force is mainly borne by the reinforced concrete slab. This fully utilizes the high tensile strength of the wooden beam and the inverted T-shaped steel beam, and the high compressive strength of the reinforced concrete slab, significantly improving the load-bearing capacity of the composite beam. However, this patent's inverted T-shaped beam divides the wooden beam into two parts, resulting in poor overall integrity. Furthermore, several bolts penetrate both parts of the wooden beam. Under load, these bolt holes become weak points, prone to stress concentration, leading to localized damage to the bolt grooves.

[0005] Solving the aforementioned technical problems is the challenge facing this utility model. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a reasonably designed, safe, and reliable embedded steel-clad wood-concrete composite beam. By innovatively combining wood, steel, and concrete and employing various efficient connection methods, it effectively solves the technical problems of existing wood-concrete composite beams, such as insufficient load-bearing capacity, limited span, easy damage to wood beams in the negative bending moment zone, and poor overall connection integrity.

[0007] The technical solution adopted by this utility model to solve its technical problem is: an embedded steel-clad wood-concrete composite beam, including a concrete slab, the lower part of which is provided with a trapezoidal groove extending along its length direction, a wooden beam is provided below the concrete slab, and the upper part of the wooden beam is provided with a trapezoidal protrusion that cooperates with the trapezoidal groove, the trapezoidal protrusion being inserted into the trapezoidal groove; a plurality of shear pins are provided along the length direction of the wooden beam, the shear pins being fixed to the upper part of the wooden beam to enhance the connection strength between the wooden beam and the concrete slab;

[0008] An outer steel beam is provided below the concrete slab, and the outer steel beam has a rectangular cavity. The wooden beam is embedded in the rectangular cavity. The concrete slab is provided with two sets of barbed bolts for fixing the outer steel beam to the lower part of the concrete slab. The two sets of barbed bolts are located on both sides of the trapezoidal groove.

[0009] Furthermore, the trapezoidal groove and the trapezoidal protrusion are perfectly matched in shape and size, and the trapezoidal groove and the trapezoidal protrusion are vertically aligned. The bottom width of the trapezoidal groove is greater than the opening width, and the bottom width of the trapezoidal protrusion is greater than the top width, so as to form an inverted trapezoidal tenon-and-mortise joint structure.

[0010] Furthermore, the shear pin is 90-degree hook-shaped and is set at an inclined angle along the cross-sectional direction of the upper part of the wooden beam. The wooden beam has an inclined hole that matches the shape of the shear pin. The shear pin is fixed by inserting it into the inclined hole and filling it with mortar. The hook section of the shear pin hooks onto the lower surface of the concrete slab, and the straight section of the shear pin is inserted and fixed to the upper part of the wooden beam.

[0011] Preferably, the shear pins are inclined at an angle of 45 degrees and spaced 200-300 mm along the length of the wooden beam to uniformly transmit the shear force between the wooden beam and the concrete slab.

[0012] Preferably, the shear pins are evenly spaced along the length of the wooden beam.

[0013] Furthermore, the outer steel beam includes a base plate, two web plates arranged opposite each other on the base plate, an upper flange connected to the upper end of the web plate, and a plurality of bolt holes that mate with the barbed bolts on the upper flange;

[0014] The rectangular cavity is formed by the web and the bottom plate, and the width of the rectangular cavity matches the width of the wooden beam, and the height of the rectangular cavity matches the height of the wooden beam, so that the wooden beam is tightly embedded in the outer steel beam.

[0015] Furthermore, the barbed bolt includes a bolt body pre-embedded in the concrete slab, and the outer surface of the bolt body is provided with a plurality of barbed segments along the axial direction of the bolt body. The bolt body is provided with a nut that mates with the outer steel beam. The plurality of barbed segments are symmetrically arranged and distributed along the vertical direction of the bolt body to enhance the anchoring strength and anti-slip capability between the outer steel beam and the concrete slab.

[0016] Preferably, a washer is provided between the nut of the barbed bolt and the upper flange of the outer steel beam. The washer is used to evenly distribute the pressure generated by the nut of the barbed bolt when tightening, and to prevent excessive local compressive stress from causing deformation or damage to the outer steel beam.

[0017] Furthermore, the wooden beams, outer steel beams, shear pins, and barbed bolts are all prefabricated components, which are assembled on site and connected to the concrete slab. After the concrete is poured and its strength reaches more than 75% of the design strength, the outer steel beams are connected and fixed to the superstructure by tightening the nuts of the barbed bolts.

[0018] Furthermore, an elastic spacer layer is provided between the wooden beam and the outer steel beam. The elastic spacer layer covers the outer surface of the wooden beam to buffer the hard contact between the steel and the wood, prevent the wood from being damaged or deformed due to friction or compression, and improve the bonding stability between the wooden beam and the steel beam.

[0019] This invention provides a strong mechanical interlocking force through an inverted trapezoidal mortise and tenon joint structure, effectively resisting vertical pull-out forces and horizontal shear forces. Simultaneously, the 90-degree hook-shaped shear pins, inclined along the length of the wooden beam, hook their hook sections onto the lower surface of the concrete slab, while their straight sections are inserted and fixed to the upper part of the wooden beam, further enhancing the shear-resistant connection between the two and preventing relative slippage.

[0020] This invention significantly enhances the anchorage strength and pull-out resistance of the bolts to the concrete by using barbed bolts pre-embedded in the concrete slab and featuring multiple rows of barbs. Nuts are used to securely connect the outer steel beam to the concrete slab, effectively transferring the longitudinal shear force between the interfaces, ensuring the interface connection strength and overall load-bearing performance of the entire composite beam, and preventing detachment and damage between components.

[0021] The main structural components of this invention, such as wooden beams, outer steel beams, shear pins, and barbed bolts, can all be prefabricated and manufactured in a standardized manner in the factory, then transported to the site for efficient assembly. This prefabricated construction method not only significantly shortens the on-site construction cycle, reduces labor costs, and minimizes the impact of wet work and construction on the environment, but also helps to ensure the processing accuracy and installation quality of each component, thereby improving the overall construction efficiency, safety, and final quality of the project. Attached Figure Description

[0022] Figure 1 This is a three-dimensional view of the wooden beam of this utility model;

[0023] Figure 2 This is a side view of the wooden beam of this utility model;

[0024] Figure 3 This is a three-dimensional view of the outer steel beam of this utility model;

[0025] Figure 4 This is a side view of the outer steel beam of this utility model;

[0026] Figure 5 This is a top view of the outer steel beam of this utility model;

[0027] Figure 6 This is a front view of the shear pin of this utility model;

[0028] Figure 7 This is a three-dimensional view of the barbed bolt of this utility model;

[0029] Figure 8 This is a front view of the barbed bolt of this utility model;

[0030] Figure 9 This is a top view of the barbed bolt of this utility model;

[0031] Figure 10 This is a three-dimensional view of the overall structure of this utility model;

[0032] Figure 11 This is a side view of the overall structure of this utility model;

[0033] Figure 12 This is a front view of the overall structure of this utility model.

[0034] The attached diagram is labeled as follows: 1. Concrete slab; 1-1. Trapezoidal groove; 2. Wooden beam; 2-1. Trapezoidal protrusion; 2-2. Main body of wooden beam; 3. Outer steel beam; 3-1. Upper flange; 3-2. Web; 3-3. Rectangular cavity; 3-4. Bolt hole; 4. Shear pin; 5. Barbed bolt; 5-1. Barb; 5-2. Bolt; 5-3. Nut. Detailed Implementation

[0035] See Figures 1 to 12 As shown, an embedded steel-clad wood-concrete composite beam includes a concrete slab 1. The lower part of the concrete slab 1 is provided with a trapezoidal groove 1-1 extending along its length. A wooden beam 2 is provided below the concrete slab 1. The upper part of the wooden beam 2 is provided with a trapezoidal protrusion 2-1 that cooperates with the trapezoidal groove 1-1. The trapezoidal protrusion 2-1 is inserted into the trapezoidal groove 1-1. A plurality of shear pins 4 are provided along the length of the wooden beam 2. The shear pins 4 are fixed to the upper part of the wooden beam 2 to enhance the connection strength between the wooden beam 2 and the concrete slab 1.

[0036] An outer steel beam 3 is provided below the concrete slab 1. The outer steel beam 3 has a rectangular cavity 3-3. The wooden beam 2 is embedded in the rectangular cavity 3-3. The concrete slab 1 is provided with two sets of barbed bolts 5 for fixing the outer steel beam 3 to the lower part of the concrete slab 1. The two sets of barbed bolts 5 are located on both sides of the trapezoidal groove 1-1.

[0037] Specifically, the concrete slab 1, the wooden beam 2, and the outer steel beam 3 form a collaborative force-bearing system under external loads. The concrete slab 1 mainly bears the upper pressure and bending moment, the wooden beam 2 bears the middle tensile stress, and the outer steel beam 3 provides lateral restraint and enhances the overall shear stiffness. The three components effectively transfer shear force between interfaces through trapezoidal tenon and mortise structure, shear pins 4, and barbed bolts 5, and jointly participate in load bearing.

[0038] Furthermore, the trapezoidal groove 1-1 and the trapezoidal protrusion 2-1 are perfectly matched in shape and size, and the trapezoidal groove 1-1 and the trapezoidal protrusion 2-1 are vertically aligned. The bottom width of the trapezoidal groove 1-1 is greater than the opening width, and the bottom width of the trapezoidal protrusion 2-1 is greater than the top width, so as to form an inverted trapezoidal tenon-and-mortise joint structure.

[0039] Furthermore, the wooden beam 2 can be made from several pieces of wood. The mating surface on the trapezoidal protrusion 2-1 of the wooden beam 2 is leveled before the trapezoidal protrusion 2-1 is inserted into the trapezoidal groove 1-1 to ensure that the mating surface is free of pits or protrusions.

[0040] Furthermore, the shear pin 4 is in the shape of a 90-degree hook, and the shear pin 4 is set at an inclined angle along the cross-sectional direction of the upper part of the wooden beam 2. The wooden beam 2 is pre-set with inclined holes that match the shape of the shear pin 4. The shear pin 4 is fixed by inserting into the inclined holes and filling them with mortar. The hook section of the shear pin 4 hooks onto the lower surface of the concrete slab 1, and the straight section of the shear pin 4 is inserted and fixed to the upper part of the wooden beam 2.

[0041] Preferably, the shear pins 4 are inclined at an angle of 45 degrees and are spaced 200-300 mm apart along the length of the wooden beam 2 to uniformly transmit the shear force between the wooden beam 2 and the concrete slab 1.

[0042] Preferably, the shear pins 4 are evenly spaced along the length of the wooden beam 2.

[0043] Furthermore, the outer steel beam 3 includes a base plate, two web plates 3-2 arranged opposite to each other on the base plate, an upper flange 3-1 connected to the upper end of the web plate 3-2, and a plurality of bolt holes 3-4 that mate with the barbed bolts 5 on the upper flange 3-1.

[0044] The rectangular cavity 3-3 is formed by the web 3-2 and the bottom plate, and the width of the rectangular cavity 3-3 matches the width of the wooden beam 2, and the height of the rectangular cavity 3-3 matches the height of the wooden beam 2, so that the wooden beam 2 is tightly embedded in the outer steel beam 3.

[0045] Preferably, the thickness of the upper flange 3-1 is 8-12mm, the thickness of the web 3-2 is 6-10mm, and the angle between the web 3-2 and the bottom plate is 90 degrees, so as to ensure the structural strength of the outer steel beam 3 and the wrapping stiffness of the wooden beam 2.

[0046] Preferably, the inner side of the web 3-2 is provided with a stiffening rib extending longitudinally, the stiffening rib is closely fitted with the side of the wooden beam 2, and the surface of the stiffening rib is provided with anti-slip protrusions perpendicular to the grain direction of the wooden beam 2.

[0047] Preferably, the bottom surface of the wooden beam 2 is bonded and fixed to the bottom plate of the outer steel beam 3 by a structural adhesive layer, or by setting anti-slip teeth to achieve mechanical interlocking, so as to enhance the interface connection strength and shear force transmission capacity between the wooden beam 2 and the outer steel beam 3.

[0048] Furthermore, the barbed bolt 5 includes a bolt 5-2 body pre-embedded in the concrete slab 1. The outer surface of the bolt 5-2 body is provided with a plurality of barbs 5-1 segments along the axial direction of the bolt 5-2 body. The bolt 5-2 body is provided with a nut 5-3 that mates with the outer steel beam 3. The plurality of barbs 5-1 segments are symmetrically arranged and distributed along the vertical direction of the bolt 5-2 body to enhance the anchoring strength and anti-slip capability between the outer steel beam 3 and the concrete slab 1.

[0049] Preferably, the barb 5-1 segments are arranged in two rows and symmetrically, with two barb 5-1 segments in each row, and the spacing between adjacent barb 5-1 segments is 50-80mm, so as to evenly distribute the anchoring force and avoid local damage to the concrete.

[0050] Preferably, the barbed bolt 5 has an anti-rotation structure on its bolt 5-2 body to prevent it from rotating within the concrete slab 1. The anti-rotation structure is an anti-rotation wing provided on the side of the bolt 5-2 body. The anti-rotation wing is symmetrically distributed and its width is greater than the diameter of the bolt 5-2 body.

[0051] Preferably, a washer is provided between the nut 5-3 of the barbed bolt 5 and the upper flange 3-1 of the outer steel beam 3. The washer is used to evenly distribute the pressure generated by the nut 5-3 of the barbed bolt 5 during tightening, preventing excessive local compressive stress from causing deformation or damage to the outer steel beam 3. The washer is a circular elastic washer made of rubber or stainless steel, and the outer diameter of the washer is larger than the diameter of the bolt hole 3-4 to expand the stress-bearing area and adapt to the connection requirements under different working conditions.

[0052] Furthermore, the wooden beam 2, the outer steel beam 3, the shear pin 4, and the barbed bolt 5 are all prefabricated components, which are connected to the concrete slab 1 on site by assembly. After the concrete is poured and its strength reaches more than 75% of the design strength, the outer steel beam 3 is connected and fixed to the upper structure by tightening the nuts 5-3 of the barbed bolt 5.

[0053] Furthermore, an elastic padding layer is provided between the wooden beam 2 and the outer steel beam 3. The elastic padding layer covers the outer surface of the wooden beam 2 to buffer the hard contact between the steel and wood, prevent the wood from being damaged or deformed due to friction or compression, and improve the bonding stability between the wooden beam 2 and the steel beam.

[0054] The technical features of this utility model not described can be implemented by or by using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this utility model, and this utility model is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model should also be within the protection scope of this utility model.

Claims

1. An embedded steel-clad wood-concrete composite beam, characterized in that: The system includes a concrete slab (1), the lower part of which is provided with a trapezoidal groove (1-1) extending along its length direction. A wooden beam (2) is provided below the concrete slab (1), and the upper part of the wooden beam (2) is provided with a trapezoidal protrusion (2-1) that cooperates with the trapezoidal groove (1-1). The trapezoidal protrusion (2-1) is inserted into the trapezoidal groove (1-1). The wooden beam (2) is provided with a number of shear pins (4) along its length direction. The shear pins (4) are fixed to the upper part of the wooden beam (2) to enhance the connection strength between the wooden beam (2) and the concrete slab (1). An outer steel beam (3) is provided below the concrete slab (1). The outer steel beam (3) has a rectangular cavity (3-3). The wooden beam (2) is embedded in the rectangular cavity (3-3). The concrete slab (1) is provided with two sets of barbed bolts (5) for fixing the outer steel beam (3) to the lower part of the concrete slab (1). The two sets of barbed bolts (5) are located on both sides of the trapezoidal groove (1-1).

2. The embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: The trapezoidal groove (1-1) and the trapezoidal protrusion (2-1) are perfectly matched in shape and size, and the trapezoidal groove (1-1) and the trapezoidal protrusion (2-1) are vertically aligned. The bottom width of the trapezoidal groove (1-1) is greater than the opening width, and the bottom width of the trapezoidal protrusion (2-1) is greater than the top width, so as to form an inverted trapezoidal tenon and mortise joint structure.

3. The embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: The shear pin (4) is 90-degree hook-shaped. The shear pin (4) is set at an inclined angle along the cross-sectional direction of the upper part of the wooden beam (2). The wooden beam (2) is pre-set with an inclined hole that matches the shape of the shear pin (4). The shear pin (4) is fixed by inserting into the inclined hole and filling it with mortar. The hook section of the shear pin (4) hooks onto the lower surface of the concrete slab (1), and the straight section of the shear pin (4) is inserted and fixed to the upper part of the wooden beam (2).

4. An embedded steel-clad wood-concrete composite beam as described in claim 3, characterized in that: The shear pins (4) are evenly spaced along the length of the wooden beam (2).

5. An embedded steel-clad wood-concrete composite beam as described in claim 3, characterized in that: The shear pins (4) are inclined at an angle of 45 degrees and are spaced 200-300 mm apart along the length of the wooden beam (2) to uniformly transmit the shear force between the wooden beam (2) and the concrete slab (1).

6. An embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: The outer steel beam (3) includes a base plate, two web plates (3-2) arranged opposite to each other on the base plate, an upper flange (3-1) connected to the upper end of the web plate (3-2) is provided on the web plate (3-2), and a plurality of bolt holes (3-4) that cooperate with the barbed bolts (5) are provided on the upper flange (3-1). The rectangular cavity (3-3) is formed by the web (3-2) and the bottom plate, and the width of the rectangular cavity (3-3) matches the width of the wooden beam (2), and the height of the rectangular cavity (3-3) matches the height of the wooden beam (2), so that the wooden beam (2) is tightly embedded in the outer steel beam (3).

7. An embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: The barbed bolt (5) includes a bolt (5-2) body embedded in the concrete slab (1). The outer surface of the bolt (5-2) body is provided with a plurality of barb (5-1) segments along the axial direction of the bolt (5-2) body. The bolt (5-2) body is provided with a nut (5-3) that mates with the outer steel beam (3). The plurality of barb (5-1) segments are symmetrically arranged and distributed along the vertical direction of the bolt (5-2) body to enhance the anchoring strength and anti-slip capability between the outer steel beam (3) and the concrete slab (1).

8. An embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: A washer is provided between the nut (5-3) of the barbed bolt (5) and the upper flange (3-1) of the outer steel beam (3). The washer is used to evenly distribute the pressure generated by the nut (5-3) of the barbed bolt (5) when tightening, and to prevent excessive local compressive stress from causing deformation or damage to the outer steel beam (3).

9. An embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: The wooden beam (2), the outer steel beam (3), the shear pin (4), and the barbed bolt (5) are all prefabricated components. They are connected to the concrete slab (1) on site by assembly. After the concrete is poured and its strength reaches more than 75% of the design strength, the outer steel beam (3) is connected and fixed to the upper structure by tightening the nuts (5-3) of the barbed bolt (5).

10. An embedded steel-clad wood-concrete composite beam as described in claim 1, characterized in that: An elastic padding layer is provided between the wooden beam (2) and the outer steel beam (3). The elastic padding layer covers the outer surface of the wooden beam (2) to buffer the hard contact between the steel and wood, prevent the wood from being damaged or deformed due to friction or squeezing, and improve the bonding stability between the wooden beam (2) and the steel beam.

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