JP2002356812A - Joint structure using studs - Google Patents

Abstract

(57) [Summary] In a reinforced concrete installation structure having a stud fixed to a base and reinforced concrete installed on the base via the stud, even if cracks occur around the stud, the concrete It is an object of the present invention to provide a structure capable of preventing collapse of a stud and maintaining an integrated function of a stud. SOLUTION: A lower area of the stud is surrounded by a flexible tubular body. Therefore, the collapse of concrete is prevented by the effect of stopping the propagation of cracks in the tubular body and the hoop effect of the tubular body restraining the concrete inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure using studs, and more particularly to a joint structure between a girder used for a bridge or the like and reinforced concrete.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing an installation structure in which a concrete slab is installed on a main girder in a conventional bridge or the like, and shows a joint portion between the concrete slab and the main girder. In FIG. 5, a concrete floor slab 104 formed of concrete 102 and reinforcing bars 103 is installed on a main girder 101, and is joined via studs 105.

The lower part of the stud 105 is fixed to the main girder 101. The stud 105 is 3 in this example.
A group of 12 * 4, forming a group of studs,
The plurality of stud groups are arranged at predetermined intervals.

[0004]

However, the prior art has the following problems. FIG. 6 is a cross-sectional view schematically illustrating a state of damage to concrete at a joint portion between a conventional concrete floor slab and a main girder. In addition,
The same components as those of the conventional concrete floor slab installation structure described with reference to FIG. 5 are denoted by the same reference numerals, and some description thereof will be omitted.

In FIG. 6, the main girder 101 made of steel and the concrete floor slab 104 are moved relative to each other due to the temperature difference between the seasons or day and night, vibration caused by a passing vehicle or wind, or introduction of prestress into concrete. Try to deviate.

However, since the main girder 101 and the concrete 102 are joined via the stud 105,
Concrete 102 is subject to compressive or tensile forces primarily between stud groups. In addition, the stud 105 has a main girder 10.
Since it is fixed to 1 in a cantilevered state, it is subjected to a force such that its lower part is dragged by the main girder 101.

As a result, the shearing force concentrates in the area near the main girder 101 of the concrete 102 inside and in the vicinity of the stud group, and cracks 107 are generated. The crack 107 is generated from a plurality of studs 105 in a group of studs, and one crack generated from one stud interferes with and propagates with another crack generated from the other stud disposed in contact with the stud. Combined, this area of concrete will collapse.
This causes a problem that the stud 105 loses its function as a joining member, and the function of integrating the concrete slab 104 and the main girder 101 (hereinafter, referred to as an integrated function) is lost.

[0008] In particular, such collapse of concrete
When the concrete strength is low, it becomes remarkable when the interval between the studs in the stud group is small.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and it is intended to suppress cracking around a stud, to reduce the delay,
Alternatively, it is an object of the present invention to provide a joint structure using studs that can reduce the generation amount and maintain the function of integrating the concrete slab and the main girder.

[0010]

The joining structure using the stud of the present invention for solving the above-mentioned problem is as follows.

[1] A joint structure having a base, a stud fixed to the base, and reinforced concrete provided on the base, wherein the stud is surrounded by a tubular body. Things.

[2] In the above [1], a through-hole is provided in the tubular body, and a reinforcing bar is provided through the through-hole, or concrete enters the through-hole. Is characterized.

[3] In the above [1] or [2], the tubular body is formed of a strip-shaped thin plate and has flexibility.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] FIG. 1 is a perspective view showing an embodiment of a joint structure using studs according to the present invention, in which a joint portion between a concrete floor slab and a main girder is shown. I see through. In FIG. 1, a concrete floor slab 4 formed by concrete 2 and reinforcing bars 3 is installed on a main girder 1 and joined via studs 5.

The lower portion of the stud 5 is fixed to the main girder 1. In this example, the stud 5 is 3 * 4 12
A group of books forms a stud group, and a plurality of the stud groups are arranged at predetermined intervals (the same as in the related art). Further, the cylindrical body 1 is surrounded by the stud group.
0 is set.

FIGS. 2A and 2B are a plan view and a side view, respectively, for explaining the cylindrical body in FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals, and a part of the description will be omitted.

In FIG. 2, a tubular body 10 is formed by forming a thin steel plate into a flat rounded square tubular shape, and is mounted on the main girder 1 without fixing or welding. Thus, the concrete 2 is isolated inside and outside the tubular body 10. The reinforcing bar 3 is provided so as to pass through the through hole 11.

Concrete enters the through holes 11 and 12, and the concrete inside and outside the cylindrical body 10 is connected only through the through holes 11 and 12. Also,
The height of the tubular body 10 is about half the height of the stud 5, and the distance between the tubular body 10 and the stud closest thereto is:
It is not more than 5 times the distance between studs (the distance between centers of studs).

FIG. 3 is a cross-sectional view schematically showing a condition of damage to a concrete portion in a joint structure using a stud according to the present invention. The same parts as those described in FIG. 1 are denoted by the same reference numerals, and a part of the description will be omitted.

In FIG. 3, since the concrete 2 is isolated inside and outside the tubular body 10 by the tubular body 10, the crack 7 generated around the stud 5 propagates when reaching the tubular body 10. It stops and there is no crack in the concrete outside the tubular body 10. In addition, the cylindrical body 1
The degree of cracking in the concrete inside 0 is
It is much lighter than the prior art, and concrete has not collapsed.

That is, since the cylindrical body 10 functions as a flexible partition wall, the propagation of cracks is stopped without generating excessive force at the interface between the side surface of the cylindrical body 10 and concrete. In addition, since it functions as a concrete hoop inside the tubular body 10 and restrains and compresses the concrete, it prevents the concrete from cracking and the concrete from collapsing.

Note that the configuration of the stud group of the present invention is not limited to the above-described embodiment, and for example, 4 * 4, 3
Any number of books * 5 may be used. Further, the cylindrical body is not limited to a thin steel plate, but is reinforced plastic (FRP).
Etc.), and the planar shape is not limited to a substantially rectangular shape.

Further, the present invention is not limited to a structure for installing a concrete floor slab on a main girder of a bridge.
Instead of the main girder, concrete plates (floor,
This can be applied to a structure having a wall or the like.

[Embodiment 2] FIGS. 4A and 4B are a plan view and a side view showing another embodiment of a joint structure using a stud according to the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and a part of the description will be omitted.

FIG. 4 shows an example in which a substantially rectangular tubular body 10 in FIG. 1 is replaced with a planar circular tubular body 20. Therefore, the same operation and effect as those of the first embodiment are obtained, and the cylindrical body 20 has a flat circular shape, so that the cylindrical body 20 reliably functions as a hoop in the concrete inside thereof. In addition, it suppresses or delays the occurrence of cracks in concrete, and prevents the cracks that have occurred from growing and propagating.

[0026]

According to the joint structure using the studs of the present invention described above, since the cylindrical body is arranged around the stud group, the occurrence of concrete cracks around the studs can be suppressed, and the delay or cracking can be prevented. Reduction of the amount of generation and prevention of propagation of the generated cracks,
Accordingly, a remarkable effect of suppressing the collapse of the concrete around the stud group can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joint portion between a concrete floor slab and a main girder, showing one embodiment of a joint structure using a stud according to the present invention.

FIGS. 2A and 2B are a plan view and a side view illustrating a tubular body in one embodiment of a joint structure using a stud according to the present invention.

FIG. 3 is a cross-sectional view schematically illustrating a damage state of a concrete portion in a joint structure using a stud according to the present invention.

FIG. 4 is a plan view and a side view illustrating a cylindrical body in another embodiment of the joint structure using the stud according to the present invention.

FIG. 5 is a perspective view showing an installation structure in which a concrete girder is installed on a main girder in a conventional bridge or the like, in which a joint between the concrete girder and the main girder is seen through.

FIG. 6 shows a conventional concrete floor slab installation structure.
It is sectional drawing which shows the damage situation of a concrete part typically. DESCRIPTION OF SYMBOLS 1 Main girder 2 Concrete 3 Reinforcement 4 Concrete floor slab 5 Stud 7 Crack 10 Cylindrical body 11 Through hole 12 Through hole 20 Cylindrical body

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsuka Nakanishi 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. 2D059 AA05 AA14 GG02 GG33 GG55 2E125 AA14 AA44 AA57 AB13 AC15 AE04 AG20 AG26 AG57 AG60 BA02 BA33 BB28 BC08 BD01 BE08 BF01 EA01 EB08 EB09

Claims (3)

[Claims] 1. A joint structure having a base, a stud fixed to the base, and reinforced concrete installed on the base, wherein the stud is surrounded by a tubular body. Joint structure using studs. 2. A through hole is provided in the cylindrical body, and a reinforcing bar is provided through the through hole, or concrete penetrates into the through hole. A joint structure using the stud according to claim 1. 3. The joint structure using studs according to claim 1, wherein the tubular body is formed of a strip-shaped thin plate and has flexibility.