Support structure of concrete slab

Abstract

To provide a concrete slab support structure capable of effectively preventing cracks from occurring due to stress concentration within concrete in transmitting a horizontal force of a concrete slab to a supporting members.SOLUTION: A concrete slab support structure is provided, which includes: a support member; concrete installed above the support member; and a stud bolt anchored in the concrete, in which one end of the stud bolt is welded to the support member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a support structure for a concrete slab.

Background Art

[0002] As a method of transmitting the horizontal force of a concrete slab to a beam, headed studs, punched plug welding, driven studs, welding (fillet welding or plug welding), bolts or high-strength bolts may be used. Among these, headed studs are often used to more firmly integrate the concrete slab and the beam. For example, Patent Document 1 describes an example of a composite beam in which a concrete slab composed of concrete and a deck plate and a steel beam are integrated by a shear connector using a headed stud.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique described in Patent Document 1 above, when bending occurs in the concrete slab, the stress in the concrete concentrates on the head of the headed stud, so there is a problem that cracks starting from the stud head are likely to occur.

[0005] Therefore, an object of the present invention is to provide a support structure for a concrete slab that can effectively prevent the occurrence of cracks due to stress concentration in the concrete when transmitting the horizontal force of the concrete slab to a support member.

Means for Solving the Problems

[0006] [1] A support structure for a concrete slab, comprising a support member, concrete poured above the support member, and stud bolts fixed to the concrete, wherein one end of the stud bolts is welded to the support member. [2] The concrete slab support structure according to [1], further comprising a first nut which is screwed onto the stud bolt from the end of the stud bolt opposite to the support member, wherein the first nut is separated from the support member. [3] The concrete slab support structure according to [2], further comprising a second nut which is screwed onto the stud bolt from the end of the stud bolt opposite to the support member, wherein the second nut is positioned between the first nut and the support member. [4] The concrete slab support structure according to [3], further comprising a plate-shaped member sandwiched between the first nut and the second nut. [5] The concrete described above constitutes a composite slab, and is a support structure for a concrete slab as described in any one of items [1] to [4]. [Effects of the Invention]

[0007] According to the above configuration, horizontal forces from the concrete slab are transmitted to the support member via stud bolts welded to the support member. Since the surface of the stud bolt has threaded grooves, it can resist being pulled out of the concrete, similar to the case of a headed stud. On the other hand, since the threaded grooves are formed over a predetermined section in the longitudinal direction of the stud bolt, the stress within the concrete can be distributed compared to the case of a headed stud where stress is concentrated only at the head, and the occurrence of cracks due to stress concentration can be effectively prevented. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows a support structure for a concrete slab according to one embodiment of the present invention. [Figure 2]This figure shows an example of arranging a nut and a plate-shaped member that are screwed onto a stud bolt in an embodiment of the present invention. [Figure 3] This figure shows an example of arranging a nut and a plate-shaped member that are screwed onto a stud bolt in an embodiment of the present invention. [Figure 4] This figure shows an example of arranging a nut and a plate-shaped member that are screwed onto a stud bolt in an embodiment of the present invention. [Figure 5] This figure shows another example of an application area of ​​an embodiment of the present invention. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0010] Figure 1 shows a support structure for a concrete slab according to one embodiment of the present invention. In the illustrated example, concrete 2 is poured above an H-shaped steel beam 1, which is a support member, to construct a concrete slab. The H-shaped steel beam 1, including the flange 11 and web 12, is an example of a support member and constitutes a beam in a building, for example. The support member is not limited to an H-shaped steel beam; various types of structural steel, such as channel steel or angle steel, can be used as support members. One end of a stud bolt 3 is welded to the upper surface of the flange 11 of the H-shaped steel beam 1, and the stud bolt 3 is fixed to the concrete 2. This constitutes a support structure that transmits the horizontal force of the concrete slab to the H-shaped steel beam 1, which is a support member. Since the surface of the stud bolt 3 has screw-like irregularities, it can resist being pulled out of the concrete 2, similar to a headed stud. On the other hand, since the screw grooves are formed over a predetermined section along the length of the stud bolt 3 (not necessarily over the entire length, and there may be parts where the screw is not formed, such as near the ends), the stress within the concrete 2 can be distributed compared to the case of a headed stud where stress is concentrated only at the head, and the occurrence of cracks due to stress concentration can be effectively prevented.

[0011] In the illustrated example, concrete 2 is poured onto deck plate 4 to form a composite slab, but deck plate 4 is not placed in the area where stud bolts 3 are anchored. Studs that penetrate deck plate 4 and are welded to H-beam 1 may be placed in a different area from the stud bolts 3. Deck plate 4 is, for example, a corrugated thin plate with alternately arranged trapezoidal peaks and grooves extending parallel to each other. The peaks and grooves may extend in a direction perpendicular to the axis of the H-beam 1, or in a direction parallel to the axis of the H-beam 1. Alternatively, a formwork member in which the deck plate and reinforced truss are integrated may be used. In other examples, concrete 2 may be poured onto a member used exclusively as formwork, such as a flat deck, to construct a concrete slab, or the formwork member may be removed after pouring the concrete 2, and no formwork member may remain after the construction of the concrete slab.

[0012] Figures 2 to 4 show examples of arranging a nut and plate-shaped member to be screwed onto a stud bolt in an embodiment of the present invention. In the example shown in Figure 2, the nut 5A is screwed onto the stud bolt 3 from the end opposite to the H-shaped steel 1. The nut 5A is spaced away from the deck plate 4 and positioned, for example, close to the end of the stud bolt 3. In addition to the threads of the stud bolt 3, the nut 5A forms a protrusion from the stud bolt 3, thereby strengthening the resistance of the stud bolt 3 to being pulled out of the concrete 2. The overall shape of the stud bolt 3 and nut 5A together is similar to a headed stud, but as described above, the threads are formed over a predetermined section in the longitudinal direction of the stud bolt 3, which allows for better stress distribution within the concrete 2 compared to a headed stud.

[0013] In the example shown in Figure 3, two nuts 5A and 5B are screwed onto the end of the stud bolt 3 opposite to the H-beam 1. Nut 5A is positioned close to the end of the stud bolt 3, as in the example in Figure 2, and nut 5B is positioned between nut 5A and the flange 11 of the H-beam 1. More specifically, nut 5B is positioned approximately midway between nut 5A and the flange 11, and spaced apart from both of them. In addition to the threaded grooves being formed over a predetermined length of the stud bolt 3, the protrusions from the stud bolt 3 formed by the nuts are increased to two locations, nut 5A and 5B, which further strengthens the resistance of the stud bolt 3 to being pulled out of the concrete 2 and further distributes the stress within the concrete 2.

[0014] In the example shown in Figure 4, nut 5B is positioned closer to nut 5A than in the example in Figure 3, and a plate-shaped member 6 is sandwiched between nuts 5A and 5B. In addition to the screw grooves being formed over a predetermined length of the stud bolt 3, the protrusions from the stud bolt 3 formed by nuts 5A and 5B, and further by the plate-shaped member 6, further strengthen the resistance of the stud bolt 3 to being pulled out of the concrete 2, and further distribute the stress within the concrete 2. Although the plate-shaped member 6 is shown as a flat plate, its cross-sectional shape is not particularly limited and can be a corrugated plate or a U-shaped curved shape, for example.

[0015] Since it is easy to screw nuts onto the stud bolts 3, as in the example above, nuts can be screwed onto them or a plate-shaped member can be clamped with nuts to form an overhang from the stud bolts 3, thereby strengthening resistance to pull-out and distributing stress within the concrete 2. In other examples, one or more nuts other than nuts 5A and 5B may be screwed onto the stud bolts 3, or one or more plate-shaped members similar to the plate-shaped member 6 may be clamped by nuts screwed onto the stud bolts 3.

[0016] FIG. 5 is a diagram showing another example of the application site of the embodiment of the present invention. In the example shown in FIG. 1, the concrete 2 was described as being placed on the deck plate 4 to form a composite slab, but the concrete 2 may form an RC slab as in the example shown in FIG. 5. In the illustrated example, an RC slab in which mesh bars 71 and reinforcing bars 72 are embedded in the concrete 2 is constructed on the main beams 1A and secondary beams 1B each made of H-shaped steel. The stud bolts 3 are welded at one end to the upper surface of the flange 11A of the main beam 1A and the upper surface of the flange 11B of the secondary beam 1B, respectively, and are fixed to the concrete 2. Also in this case, the horizontal force of the RC slab is transmitted to the main beam 1A and the secondary beam 1B, which are support members, through the stud bolts 3, and the effect of dispersing the stress in the concrete 2 by the stud bolts 3 can be obtained. Further, the examples described above with reference to FIGS. 2 to 4 are also applicable to the case of an RC slab as shown in FIG. 5.

[0017] As described above, the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to these examples. It is obvious that those skilled in the technical field to which the present invention pertains can conceive of various modification examples or correction examples within the scope of the technical idea described in the claims, and it is naturally understood that these also belong to the technical scope of the present invention.

Description of Reference Numerals

[0018] 1... H-shaped steel, 1A... main beam, 1B... secondary beam, 11, 11A, 11B... flange, 12... web, 2... concrete, 3... stud bolt, 4... deck plate, 5A, 5B... nut, 6... plate-like member, 71... mesh bar, 72... reinforcing bar.

Claims

1. Support member and A steel plate positioned above the support member, Concrete poured above the support member and the steel plate Stud bolts that are fixed to the concrete and Equipped with, One end of the stud bolt is welded to the support member. The steel plate is not placed in the area where the stud bolt is fixed. The aforementioned stud bolt is a shaft-shaped member without a head. A concrete slab support structure wherein the surface of the stud bolt has threaded grooves formed over a predetermined length of the stud bolt.

2. The stud bolt is further fitted with a first nut which is screwed onto the stud bolt from the end of the stud bolt opposite to the support member, The concrete slab support structure according to claim 1, wherein the first nut is spaced apart from the support member.

3. The stud bolt is further fitted with a second nut which is screwed onto the stud bolt from the end of the stud bolt opposite to the support member, The concrete slab support structure according to claim 2, wherein the second nut is positioned between the first nut and the support member.

4. The concrete slab support structure according to claim 3, further comprising a plate-shaped member sandwiched between the first nut and the second nut.

5. The concrete is a support structure for a concrete slab according to any one of claims 1 to 4, wherein the concrete constitutes a composite slab.

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