JP3432568B2 - Joint material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint material for a holding concrete when a waterproof layer, a heat insulating layer and the like are provided on the upper surface of a slab such as a rooftop and the holding concrete is placed on the upper surface thereof.

[0002]

2. Description of the Related Art The top surface of a slab such as a rooftop is waterproofed or provided with a heat insulating layer, and then a holding concrete is poured. At this time, there is a joint material in the holding concrete, and the holding concrete layer is divided by the joint material,
This prevents the parapet from being pushed out, the rising waterproof layer from being broken, and the pressing concrete layers from being pushed up when the pressing concrete layer expands and contracts due to temperature changes.

The joint material is fixed to the heat insulation layer with butyl adhesive tape or the like. It is good to place concrete immediately after fixing, but if it is done after a long time, it may rain during that time. . Therefore, as shown in FIG. 5, a groove 1 is formed on the back surface of the joint material A (a surface fixed to the heat insulating layer B) over the entire width in the width direction, and the joint material A is passed through the groove 1.
Rainwater passes through the inside.

On the other hand, when the pressing concrete is placed, the pressing concrete also enters the groove 1.

[0005]

As shown in FIG. 5, the conventional groove 1 is formed straight with the same width over the entire length of the back surface of the joint material A, and the concrete in the groove 1 is also straightened. It will solidify in the same width. The straight concrete portion in the groove 1 protrudes without following the compression of the pressing concrete layer, and cannot exert the original cushioning action of the joint material A when the pressing concrete layer expands, contracts, or shifts. However, there is a possibility that the parapet may be extruded or the rising waterproof layer may be broken.

Under the above circumstances, it is an object of the present invention to surely prevent extrusion of the parapet and breakage of the rising waterproof layer.

[0007]

In order to solve the above-mentioned problems, in the present invention, the groove is made thin in the middle or bent in the middle.

[0008]

The joint material according to the present invention having the above structure is
As in the conventional case, the pressing concrete enters the groove on the back side, but the pressing concrete layer on the upper surface of the slab expands and contracts,
When the expansion / contraction force is applied to the groove portion, the groove portion is thin or bent in the middle, and thus the groove portion is broken by the expansion / contraction force. Since the joint material is usually made of an elastic material such as styrofoam, the folding action is smoothly performed.

[0009]

The present invention is configured as described above, and since the concrete layer in the groove does not hinder the action of the joint material due to the above-mentioned action, the pushing out of the parapet, the breakage of the rising portion waterproof layer, etc. There is little risk of

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment is shown in FIG. 1, and this joint material A is a self-supporting type having legs on both lower sides of a joint body 10 and is made of a resin foam such as polystyrene, polypropylene, polyurethane or polyethylene. On the rear surface of the leg of the joint material A, a required number of grooves 12 are formed in a V shape as shown in FIG. The width and the number of the grooves 12 are arbitrary. Groove 12
Is preferably bent so that the opening at the other end cannot be seen when viewed straight from one end to the other end (from top to bottom in FIG. 1B).

The joint material A of the embodiment shown in FIG. 2 comprises a joint body 10 and its base 11, and a groove 12 is formed on the back surface of the base 11. Joint material A of the embodiment shown in FIG.
Is made of only the joint body 10, and the groove 12 is formed on the back surface thereof.

The joint material A of each example is fixed to the upper surface of the slab by a butyl adhesive tape, and the joint material A of FIG. 3 is fixed by a mortar dumpling if necessary. After this fixing, presser concrete is placed. By this casting, concrete also enters the groove 12. Further, even if it rains before placing, rainwater flows through the groove 12.

When the pressing concrete layer expands or contracts after the pressing concrete is poured, the expansion or contraction is absorbed by the expansion or contraction of the joint material A. Further, since the concrete in the groove 12 is bent in the middle, it is easily broken by the expansion and contraction force, and no internal stress is generated.

The shape of the groove 12 is as shown in FIG.
As shown in (b), it is possible to make the middle thin, (c) in the same figure,
Any shape may be adopted as long as it has a bent shape as shown in (d), or is bent by bending as shown in (e) to (g) of FIG. In the figure, 12 a is a protrusion in the groove 12 or between the grooves 12. The "thin" includes not only a narrow width as shown, but also a thin (shallow) thickness (depth).

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing a part of an embodiment,
(B) Rear view of the same part

FIG. 2 is a partial perspective view of another embodiment.

FIG. 3 is a partial perspective view of another embodiment.

FIG. 4A to FIG. 4G are partial rear views of another embodiment.

5A is a partial perspective view of a conventional example, and FIG. 5B is a rear view of the same portion.

[Explanation of symbols]

A joint material 10 joint body 11 Joint base fixed base 12 grooves

Claims (2)

(57) [Claims] 1. A joint material A for holding concrete, which is fixed to the upper surface of a slab such as a rooftop, and is characterized by the following points. Grooves 12 are formed on the back surface of the joint material A over the entire length in the width direction, and the grooves are thin in the middle. 2. A joint material for a holding concrete, which is fixed to the upper surface of a slab such as a rooftop, characterized by the following points. Grooves 12 are formed on the rear surface of the joint material over the entire width in the width direction, and the grooves are bent in the middle.