Prefabricated steel-concrete composite beam and construction method thereof

Abstract

The invention relates to a prefabricated steel-concrete composite beam and a construction method thereof, the prefabricated steel-concrete composite beam comprises four steel plates which are parallel to one another and are arranged in a rectangular shape in the circumferential direction, a gap is reserved between every two adjacent steel plates in the circumferential direction, a fixing rod is welded between every two adjacent steel plates, concrete is poured among the four steel plates, and the matching sections of the four steel plates and the concrete are rectangular; comprising the following steps that S1, firstly, four steel plates are spliced into a whole through fixing rods; and S2, a formwork is built, the whole formed through splicing is put into the formwork, then concrete is poured into the formwork, the concrete is air-dried and solidified after being vibrated, and the formwork is taken out after forming. The method has the advantage that the use performance of the steel-concrete composite beam is improved.

Description

Technical Field

[0001] This application relates to the field of building construction technology, and in particular to a precast steel-concrete composite beam and its construction method. Background Technology

[0002] A steel-concrete composite beam is a transverse load-bearing structural member consisting of steel beams and concrete slabs connected by shear connectors to share the load. It combines the advantages of both steel and concrete. Steel has high tensile strength, while concrete has good compressive strength. The combination of the two can give full play to their respective advantages, improve the load-bearing capacity and stiffness of the structure, and save on steel usage compared to pure steel structures.

[0003] However, continuous steel-concrete composite beams will experience unfavorable conditions in the negative bending moment zone, with the concrete being under tension and the steel beam under compression. This can lead to problems such as bending deformation of the steel beam as a whole and cracking of the concrete slab, resulting in a decrease in the stiffness and durability of the composite beam, which is obviously insufficient. Summary of the Invention

[0004] To improve the performance of steel-concrete composite beams, this application provides a precast steel-concrete composite beam and its construction method.

[0005] Firstly, this application provides a precast steel-concrete composite beam, which adopts the following technical solution: A precast steel-concrete composite beam includes four parallel steel plates arranged in a rectangular shape around the perimeter. There is a gap between two adjacent steel plates around the perimeter and a fixing rod is welded between them. Concrete is poured between the four steel plates, and the cross section of the four steel plates and concrete is rectangular.

[0006] By adopting the above technical solution, four steel plates, together with multiple fixing rods, are directly formed into a whole and shaped inside the concrete. The steel plates cover the outer surface of the concrete. The two work together, and the steel plates can resist the tensile force on the concrete, while the concrete can resist the compressive force on the steel plates, thereby improving the overall stiffness and durability of the steel-concrete composite beam.

[0007] Optionally, the ends of the four steel plates are connected to an inner end ring. An outer end ring is connected to the side of the inner end ring facing away from the steel plate. The outer end ring is provided with mounting lugs for bolting to the I-beam. An elastic bladder is arranged between the inner end ring and the outer end ring. The elastic bladder is hollow and conical in shape along the direction away from the midpoint of the steel plate length, and its diameter gradually decreases. A rotating disk is arranged at the end of the elastic bladder with a smaller diameter. A rotating rod extending into the concrete is arranged on the rotating disk. The rotating rod is densely covered with elastic rods.

[0008] By adopting the above technical solution, during the splicing of the four steel plates, inner end rings, elastic bladders, and outer end rings are sequentially installed at the ends of the four steel plates, thereby arranging the rotating rod between the four steel plates. After the concrete is poured, the worker manually rotates the rotating wheel, which drives the elastic rod to stir the concrete, thus achieving the effect of vibration, reducing air bubbles and voids in the concrete, and improving the curing and forming quality of the concrete.

[0009] Optionally, a support is arranged on any steel plate, and multiple limiting plates are circumferentially distributed on the support relative to the axis of the rotating rod. The limiting plates are inclined towards the axis of the rotating rod along the direction close to the rotating disk. The end of the rotating rod away from the rotating disk is located between the multiple limiting plates and a protruding ring is arranged on the outer circumferential wall. The limiting plates abut against the outer circumferential wall of the rotating rod.

[0010] By adopting the above technical solution, workers can hammer one end of the rotating rod relative to the convex ring into several limiting plates by striking it. This not only supports the end of the rotating rod, but also causes the elastic rod to move slightly axially when the worker manually rotates the turntable, further improving the overall mixing of the concrete.

[0011] Optionally, the outer end ring is provided with a fastening lug extending into the concrete, the fastening lug being wavy.

[0012] By adopting the above technical solution, the fastening ear plate is wavy and formed in the concrete, thereby improving the connection strength between the outer end ring and the concrete.

[0013] Optionally, the rotary disk includes an inner rotary disk bolted to a rotating rod and an outer rotary disk bolted to the inner rotary disk, and a clamping groove for clamping the elastic bladder is arranged at the junction of the inner rotary disk and the outer rotary disk.

[0014] By adopting the above technical solution, once the concrete has completely dried and hardened, workers can remove the outer turntable separately, saving materials.

[0015] Optionally, the rotating rod is a hollow rod.

[0016] By adopting the above technical solution, since the rotating rod is formed in concrete, it is a disposable material. Therefore, making the rotating rod hollow can reduce material consumption.

[0017] Optionally, the end of the rotating rod located between multiple limiting plates is frustoconical.

[0018] By adopting the above technical solution, the frustum shape facilitates the rotating rod to overcome the deformation force of the limiting plate and bring the convex ring between several limiting plates.

[0019] Secondly, the construction method for a precast steel-concrete composite beam provided in this application adopts the following technical solution, including the following steps: S1. First, the four steel plates are spliced ​​together to form a whole using fixing rods; S2. Build a formwork, place the assembled whole into the formwork, then pour concrete into the formwork. After the concrete is vibrated and air-dried to solidify, remove the formwork after it is formed.

[0020] By adopting the above technical solution, four steel plates, together with multiple fixing rods, are directly formed into a whole and shaped inside the concrete. The steel plates cover the outer surface of the concrete. The two work together, and the steel plates can resist the tensile force on the concrete, while the concrete can resist the compressive force on the steel plates, thereby improving the overall stiffness and durability of the steel-concrete composite beam.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. Four steel plates, together with multiple fixing rods, are directly formed into a whole and molded inside the concrete. The steel plates cover the outer surface of the concrete. The two work together. The steel plates can resist the tensile force on the concrete, while the concrete can resist the compressive force on the steel plates, thereby improving the overall stiffness and durability of the steel-concrete composite beam. 2. During the splicing of the four steel plates, inner end rings, elastic bladders, and outer end rings are sequentially installed at the ends of the four steel plates, thus positioning the rotating rod between the four steel plates. After the concrete is poured, workers manually rotate the rotating wheel, which drives the elastic rod to stir the concrete, thereby achieving the effect of vibration, reducing air bubbles and voids in the concrete, and thus improving the curing and forming quality of the concrete. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of Embodiment 1 of this application.

[0023] Figure 2 This is a cross-sectional view showing the positional relationship between the rotating rod, the elastic rod, and the support in Embodiment 1 of this application.

[0024] Figure 3 This is a schematic diagram showing the positional relationship between the I-beam, the support block, and the threaded rod in Embodiment 1 of this application.

[0025] Explanation of reference numerals in the attached drawings: 1. Steel plate; 2. Fixing rod; 3. Concrete; 4. Inner end ring; 5. Outer end ring; 6. Mounting ear plate; 7. Elastic bladder; 8. Rotary disc; 81. Inner turntable; 82. Outer turntable; 9. Rotating rod; 10. Elastic rod; 11. Support; 12. Limiting plate; 13. Protruding ring; 14. Clamping groove; 15. Precast pile; 16. I-beam; 17. Support block; 18. Support component; 19. Threaded rod. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0027] Example 1 Embodiment 1 of this application discloses a precast steel-concrete composite beam.

[0028] Reference Figure 1 The precast steel-concrete composite beam consists of four parallel steel plates 1 arranged in a rectangular shape around the perimeter. There is a gap between two adjacent steel plates 1 around the perimeter and a fixing rod 2 is welded between them. Concrete 3 is poured between the four steel plates 1. The cross section of the four steel plates 1 and the concrete 3 is a rectangle with rounded corners.

[0029] Reference Figure 2 The ends of the four steel plates 1 are welded together with an inner end ring 4. An outer end ring 5 is bolted to the side of the inner end ring 4 facing away from the steel plate 1. An installation ear plate 6 for bolting to the I-beam 16 is integrally formed on the outer end ring 5.

[0030] Reference Figure 2 Multiple fastening lugs (not shown in the figure) are also welded onto the outer end ring 5. The fastening lugs are wavy and extend into the concrete 3 and are formed therein, which helps to improve the structural strength between the outer end ring 5 and the concrete 3.

[0031] Reference Figure 2 An elastic bladder 7 is sandwiched between the inner end ring 4 and the outer end ring 5. The elastic bladder 7 is hollow and cone-shaped along the direction away from the midpoint of the length of the steel plate 1, and its diameter gradually decreases. A rotating disk 8 is arranged at the end of the elastic bladder 7 with a smaller diameter.

[0032] Reference Figure 2 The turntable 8 includes an inner turntable 81 and an outer turntable 82 that are coaxial and bolted together. The outer turntable 82 is located on the side of the inner turntable 81 that is away from the fixed rod 2. A clamping groove 14 for clamping the elastic bladder 7 is arranged at the junction of the inner turntable 81 and the outer turntable 82.

[0033] Reference Figure 2 The inner turntable 81 is coaxially bolted to one side of the outer turntable 82, extending into the concrete 3 between the four steel plates 1. The turntable 9 is a hollow rod, and elastic rods 10 are densely distributed on the turntable 9. The elastic rods 10 are made of elastic metal.

[0034] Reference Figure 2 A support 11 is welded onto any steel plate 1. Multiple limiting plates 12 are welded onto the support 11 at intervals around the axis of the rotating rod 9. The limiting plates 12 are arranged at an inclination toward the axis of the rotating rod 9 along the direction close to the rotating disc 8.

[0035] Reference Figure 2 The end of the rotating rod 9 away from the rotating disk 8 is truncated cone-shaped and used to insert between multiple limiting plates 12. A protruding ring 13 is integrally formed on the outer circumferential wall of the rotating rod 9 between the multiple limiting plates 12, and the limiting plates 12 abut against the outer circumferential wall of the rotating rod 9.

[0036] Reference Figure 2 During construction, workers first weld the support 11 to any one of the steel plates 1, and then weld the four steel plates 1 together to form a whole by means of the fixing rod 2. Then, the inner end ring 4 is welded together at the ends of the four steel plates 1. The inner turntable 81 is connected to the rotating rod 9 in advance, and then the end of the rotating rod 9 opposite to the convex ring 13 is pushed into the space between multiple limiting pieces 12 by hammering.

[0037] An outer ring 5 is installed on the inner ring 4, and the two work together to clamp the larger end of the elastic bladder 7. Finally, the smaller end of the elastic bladder 7 is inserted into the clamping groove 14 at the interface between the inner turntable 81 and the outer turntable 82.

[0038] The assembled unit is placed into the casting formwork, and then concrete 3 is poured into the formwork. The worker manually rotates the turntable 8, which drives the densely packed elastic rods 10 to rotate via the rotating rod 9, thereby agitating the concrete 3 and thus vibrating it. After the concrete 3 has completely dried and hardened, the formwork is removed.

[0039] Reference Figure 2 and Figure 3 During the actual installation of the composite beam, firstly, I-beams 16 are bolted to the precast piles 15. Then, support members 18 are arranged on the support blocks 17 that are attached to the precast piles 15. The support members 18 on two adjacent precast piles 15 are supported by threaded rods 19. The threaded rods 19 are threadedly connected to the support members 18. The workers tighten the threaded rods 19 so that the support members 18 are firmly supported on the precast piles 15.

[0040] Reference Figure 2 and Figure 3 The mounting lugs 6 at both ends of the steel-concrete composite beam are bolted to the I-beams 16 and mounted on the support members 18. The support members 18 have a pre-reserved arc surface to offset the shear stress caused by gravity when heavy objects are pressed on the composite beam.

[0041] The implementation principle of Example 1 is as follows: During construction, the worker first welds the support 11 to any steel plate 1, then welds the four steel plates 1 together to form a whole using the fixing rod 2, and then welds the inner end ring 4 together at the ends of the four steel plates 1. The inner turntable 81 is pre-connected to the rotating rod 9, and then the end of the rotating rod 9 opposite the convex ring 13 is pushed into the space between multiple limiting plates 12 by tapping. The outer end ring 5 is installed on the inner end ring 4, and the two cooperate to clamp the larger end of the elastic bladder 7. Finally, the smaller end of the elastic bladder 7 is inserted into the clamping groove 14 at the interface between the inner turntable 81 and the outer turntable 82. The assembled whole is placed into the casting mold, and then concrete 3 is poured into the mold. The worker manually rotates the turntable 8, and the turntable 8 drives the densely packed elastic rods 10 to rotate through the rotating rod 9, thereby agitating the concrete 3 and thus vibrating it. After the concrete 3 has completely dried and cured, the mold is removed.

[0042] Example 2 Embodiment 2 of this application discloses a construction method for a precast steel-concrete composite beam.

[0043] The construction method for precast steel-concrete composite beams includes the following steps: S1. First, weld the support 11 to any one of the steel plates 1. Then, weld the four steel plates 1 together to form a whole by means of the fixing rod 2. Then, weld the inner end ring 4 together at the ends of the four steel plates 1. Connect the inner turntable 81 to the rotating rod 9 in advance. Then, push the end of the rotating rod 9 relative to the convex ring 13 into the space between the multiple limiting pieces 12 by tapping.

[0044] An outer ring 5 is installed on the inner ring 4 and the two work together to clamp the larger end of the elastic bladder 7. Finally, the smaller end of the elastic bladder 7 is inserted into the clamping groove 14 at the interface of the inner turntable 81 and the outer turntable 82. S2. Build the formwork and place the assembled unit into it. Then, pour concrete 3 into the formwork. Workers manually rotate the rotary drum 8, which, through the rotating rod 9, drives the densely packed elastic rods 10 to rotate, thereby agitating the concrete 3 and thus vibrating it. After the concrete 3 has completely dried and hardened, remove the formwork.

[0045] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A precast steel-concrete composite beam, characterized in that: It includes four parallel steel plates (1) arranged in a rectangular shape around the perimeter. There is a gap between two adjacent steel plates (1) and a fixing rod (2) is welded between them. Concrete (3) is poured between the four steel plates (1). The cross section of the four steel plates (1) and the concrete (3) is rectangular.

2. The precast steel-concrete composite beam according to claim 1, characterized in that: The ends of the four steel plates (1) are connected to an inner end ring (4). The inner end ring (4) is connected to an outer end ring (5) on the side facing away from the steel plate (1). The outer end ring (5) is provided with mounting lugs (6) for bolting to the I-beam (16). An elastic bladder (7) is arranged between the inner end ring (4) and the outer end ring (5). The elastic bladder (7) is hollow and cone-shaped along the direction away from the midpoint of the length of the steel plate (1) and the diameter gradually decreases. A rotating disk (8) is arranged at the end of the elastic bladder (7) with a smaller diameter. A rotating rod (9) extending into the concrete (3) is arranged on the rotating disk (8). Elastic rods (10) are densely distributed on the rotating rod (9).

3. The precast steel-concrete composite beam according to claim 2, characterized in that: A support (11) is arranged on any steel plate (1). Multiple limiting pieces (12) are distributed circumferentially on the support (11) relative to the axis of the rotating rod (9). The limiting pieces (12) are arranged inclined towards the axis of the rotating rod (9) along the direction close to the rotating disk (8). The end of the rotating rod (9) away from the rotating disk (8) is located between the multiple limiting pieces (12) and a protruding ring (13) is arranged on the outer circumferential wall. The limiting pieces (12) abut against the outer circumferential wall of the rotating rod (9).

4. The precast steel-concrete composite beam according to claim 2, characterized in that: The outer end ring (5) is provided with a fastening lug extending into the concrete (3), and the fastening lug is wavy.

5. The precast steel-concrete composite beam according to claim 2, characterized in that: The turntable (8) includes an inner turntable (81) bolted to the turntable (9) and an outer turntable (82) bolted to the inner turntable (81). A clamping groove (14) for clamping the elastic bladder (7) is arranged at the junction of the inner turntable (81) and the outer turntable (82).

6. The precast steel-concrete composite beam according to claim 2, characterized in that: The rotating rod (9) is a hollow rod.

7. The precast steel-concrete composite beam according to claim 3, characterized in that: The end of the rotating rod (9) located between multiple limiting plates (12) is truncated cone-shaped.

8. A construction method for a precast steel-concrete composite beam according to any one of claims 1-7, characterized in that: Includes the following steps: S1. First, the four steel plates (1) are spliced ​​together to form a whole by fixing rod (2); S2. Build a mold frame, put the assembled whole into the mold frame, and then pour concrete (3) into the mold frame. The concrete (3) is vibrated and then air-dried and cured. After molding, the mold frame is removed.

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