JPH0748880A - Crack inducing joint device for reinforced concrete wall-like structure - Google Patents

Abstract

PURPOSE:To control the temperature cracks generated on a structure, improve work efficiency, shorten the construction period, and reduce the construction cost by integrally protruding T-shaped cross section portions on both sides of a cylinder hollow portion having V-shaped recesses. CONSTITUTION:V-shaped recesses are provided on a pair of semi-circle sections 2 made of a steel plate, and straight line sections 3 having end section bent pieces 3a in the diameter direction of the semi-circle sections 2 from both side end sections are stuck. T-shaped cross section portions extended in the diameter direction are protruded on both sides of a cylinder hollow portion having V-shaped recesses. Elastic sealing materials 5 are inserted into the V-shaped recesses to prevent the infiltration and sticking of placed concrete to the recesses. The expansion of the concrete section is followed by the recesses, and the water cutoff function of the crack occurrence cross section of concrcete can be exerted by the T-shaped cross section portions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crack-inducing joint device for controlling temperature cracks generated in a massive reinforced concrete wall-shaped structure.

[0002]

2. Description of the Related Art Generally, for temperature cracks that occur in a wall-like structure of massive reinforced concrete, cross-section reducing portions are provided at regular intervals in the longitudinal direction of the structure to induce cracks in the same, and There is a method of preventing the occurrence of cracks in the area of and also facilitating the post-treatment at the cracked part. The joint provided for this purpose is called a crack-inducing joint.

In the prior art, for example, Japanese Patent Application Laid-Open No. 62-133226 (Japanese Patent Application No. 60-2694) proposed by the present applicant.
No. 22), since the cross-section reduced portion is provided, a pipe such as a vinyl chloride pipe or a steel pipe is installed so as to withstand the lateral pressure at the time of placing concrete and to easily fill the concrete after cracking occurs. Moreover, in order to maintain the water blocking function of the section where the pipe is installed after the occurrence of a crack, a stretchable water blocking plate made of vinyl chloride or the like that can follow the crack is separately embedded.

[0004]

In the above-mentioned prior art, it is necessary to separately install a pipe for providing a concrete cross-section reduction portion and a water stop plate having a water stop function. However, it is not easy to maintain the respective positions and shapes against the pressure and flow pressure during concrete pouring in a narrow concrete cross section. Therefore, it takes a lot of time to install the pipe and the water blocking plate, and it is not possible to improve the work efficiency of the concrete construction, resulting in an increase in the construction cost.

The present invention has been proposed in view of the above-mentioned problems of the prior art. The purpose of the present invention is to reduce and maintain the cross-sectional area for inducing cracks in concrete, to follow the cracks, and to expand and contract. The point is to provide a joint device for cracking of reinforced concrete wall-like structures that also has a waterproof function, improves the workability of concrete construction, and can reduce the construction cost.

[0006]

In order to achieve the above object, a crack inducing joint device for a reinforced concrete wall-like structure according to the present invention is a hollow cylindrical portion having a V-shaped fold and a hollow cylindrical portion. It is composed of a T-shaped cross-sectional shape portion which is integrally provided on both sides of the shaped portion so as to project integrally therewith.

[0007]

Since the crack preventing device for a reinforced concrete wall-like structure according to the present invention is constructed as described above,
The hollow cylindrical portion embedded in the concrete wall-like structure exerts a function of reducing the concrete cross section, and the V-shaped folding portion provided in the hollow cylindrical portion follows expansion and contraction of the concrete portion. The T-shaped cross-section portions projecting on both sides of the hollow cylindrical portion exert a water-stopping function in the cross-section in which cracking occurs in concrete.

[0008]

EXAMPLE An example in which the present invention is applied to the retaining wall shown in FIGS. 6 to 8 will be described below. In the construction of the retaining wall, the concrete of the bottom slab a is cured after being placed, the crack inducing joint device A is installed on the induced joint setting line b, and the concrete of the wall c is cured after being placed for a certain time. After the elapse, a crack is induced along the induced joint setting line b.

FIG. 1 shows an embodiment of a crack inducing joint device A according to the present invention. As shown in FIG. 2, a pair of steel plates having a V-shaped folded portion 1 or a semicircular portion 2 made of a stainless steel plate is provided. A cylindrical hollow portion having V-shaped folds 1 by adhering linear portions 3 having end bending pieces 3a in the diametrical direction of the semicircular portion 2 with adhesives 4 from both end portions. When,
A crack inducing joint device A composed of a T-shaped cross-sectional shape portion extending diametrically on both sides of the hollow cylindrical portion is formed.
In the figure, reference numeral 5 denotes an elastic sealing material fitted in the V-shaped folded portion 1, into which concrete poured into the V-shaped folded portion 1 enters and adheres, and the expansion and contraction function of the folded portion 1 is improved. It is something that should not be damaged. In the figure, 6 is a wall reinforcing bar, and 7 is a wall-inducing joint.

Since the crack inducing joint device A of the present embodiment is constructed as described above, the V-shaped fold portion 1 exerts the following expansion / contraction function x of the induced crack 8 generated in the concrete, and the semicircular shape. Section 2 has a cross-section reduction function y
The straight line portions 3 extending from the hollow cylindrical portion share the water-stopping function z, exhibiting the work efficiency of the concrete construction and reducing the construction cost.

[0011]

As described above, the crack inducing joint device for a reinforced concrete wall-like structure according to the present invention has a T-shape integrally with the hollow hollow portion having a V-shaped fold on both sides thereof. Due to the projecting cross-sectional shape portion, the V-shaped folding portion provided in the cylindrical hollow shape portion has a function of expanding and contracting to follow cracks, the circular hollow shape portion has a function of reducing the cross-section, and a T-shaped cross-sectional shape portion. By doing so, the water-stopping function is demonstrated, which can improve the work efficiency of concrete construction, shorten the construction period, and reduce the construction cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a crack-inducing joint device for a reinforced concrete wall-like structure according to the present invention.

FIG. 2 is a sectional view of a component piece of the crack inducing joint device.

FIG. 3 is a vertical cross-sectional view showing a usage state of the crack inducing joint device.

FIG. 4 is a cross-sectional view showing an operating state of the crack inducing joint device.

FIG. 5 is an explanatory diagram of functions of respective parts of the crack inducing joint device.

FIG. 6 is a front view of a retaining wall to which the crack inducing joint device of the present invention is applied.

FIG. 7 is a plan view of the retaining wall.

FIG. 8 is an arrow view of FIG. 6 and FIG. 7.

[Explanation of symbols]

 A Crack-inducing joint device 1 V-shaped bent portion 2 Semi-circular portion 3 Straight portion 3a End bent piece 4 Adhesive 5 Elastic sealing material 6 Wall rebar 7 Wall-induced joint 8 Induced crack

Claims (1)

[Claims] 1. A reinforced concrete comprising a hollow cylindrical portion having a V-shaped folded portion and a T-shaped cross-sectional portion integrally projecting on both sides of the hollow cylindrical portion. Joint cracking device for wall structure.