JPS6243019Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is embedded in the joint surfaces of concrete products such as precast concrete pipes used for culverts, common ditches, manholes, etc., and precast concrete U-shaped grooves used for side ditches, waterways, etc. Regarding joint material.

In order to prevent water leakage at the joints of concrete products, there are various joint construction methods for joints. From the viewpoint of joint surface strength, water leakage prevention effect, durability, and on-site workability, rubber joint filler is embedded in the joint surface of one concrete product, and the other joint surface is pressed to compress the joint material. This method is considered to be the best. However, embedding rubber joint material into the joint surfaces of concrete products has the disadvantage of poor yield and poor productivity. That is, first, the joint material is fitted into the groove formed in the formwork, but the work efficiency is poor due to the hardness of the rubber and the frictional force of the surface. Second, the joint material inserted into the groove causes strain on the surface of the joint material in contact with the groove wall, and there is internal stress that causes it to pop out of the groove. Easy to leave.

The present invention solves the above-mentioned problems, and includes a rod-shaped rubber having an adhesive surface and a constriction or bulge for preventing pull-out along the length, and a rod-shaped rubber having an adhesive surface corresponding to the adhesive surface along the length. This joint material for concrete products is made by bonding the adhesive surfaces of closed-cell sponge together.

The configuration of the present invention will be explained in detail below with reference to the drawings.

As shown in FIG. 1, the joint material 1 is made by adhering a rod-shaped rubber and a rod-shaped closed cell sponge along the length direction, and consists of a rubber part 2 and a sponge part 3. A constriction 4 is formed in the rubber part 2 along its length to prevent the joint material 1 from separating from the concrete product. The rubber part 2 is embedded in the concrete, and the sponge part 3 is anchored to the joint surface of the concrete product while protruding from the concrete surface. Figure 2 is an example of concrete products 10
The joint material 1 is placed in the concave part of the joint surface 10a of the sponge part 3.
It is embedded in a state where it protrudes. FIG. 3 shows a state where the concrete products 10 and 12 are joined, and the convex part 13 formed on the joint surface 12a of the concrete product 12 presses and deforms the sponge part 3,
The convex portion 13 and the sponge portion 3 are in close contact with each other. In this case, since the sponge portion 3 is a closed cell sponge, it does not allow water to pass through, and since it has better adhesion than rubber, it can sufficiently prevent water leakage. Since the rubber part 2 is embedded in the concrete, it can sufficiently resist tensile, compressive and other external forces. FIG. 4 shows a mold structure for forming the joint shown in FIG. A joint bar 5 having a trapezoidal cross section is fixed to the inside of the formwork weir plate 7 through a hole 8 by welding. A groove 6 is bored at the top of the joint bar 5, and the sponge portion 3 of the joint material 1 is inserted into the groove 6 before concrete is poured. Sponge is more flexible than rubber and has less surface friction, so it not only has good work efficiency, but also reduces distortion of the sponge part 3 after insertion and adheres well to the wall of the groove 6, reducing vibrations during concrete compaction. It is also difficult to leave. FIG. 5 is a sectional view showing another embodiment.
The joint material 21 consists of a rubber part 22 and a sponge part 23, but the rubber part 22 has a bulging part 24 instead of a constriction. The joint material 31 has a concave-convex fit between the bonding surfaces of the rubber portion 32 and the sponge portion 33 to improve the strength of the bonded portion. Note that the rubber portion and the sponge portion are bonded using an adhesive or pressure bonding during extrusion molding.

The joint material of this invention has superior water leakage prevention effect compared to conventional rubber joint materials. Furthermore, it is easy to attach to the formwork, and there is little risk of it coming off during concrete compaction, improving yield. The present invention has great practical value.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a joint material that is an embodiment of the present invention, Fig. 2 is a sectional view of a concrete product in which the joint material is embedded, Fig. 3 is a sectional view showing the joined state of the concrete product, and Fig. 4 5 is a cross-sectional view showing a state in which the joint material is attached to the formwork, and FIG. 5 is a cross-sectional view showing another embodiment. 1, 21, 31... joint material, 2, 22, 32...
...Rubber part, 3, 23, 33...Sponge part, 4...
... Tie, 5... Joint bar, 7... Weir board, 10,1
2... Concrete product, 11... Recess, 13...
...Convex portion, 24...Bulging portion.

Claims (1)

[Scope of utility model registration request] A rod-shaped rubber having an adhesive surface and a constriction or bulge for preventing pull-out along the length direction and a rod-shaped closed cell sponge having an adhesive surface corresponding to the adhesive surface along the length direction are bonded together. A joint material for concrete products made of