JPH0420106Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a water-swellable round piece, specifically a water-swellable round piece for repairing concrete structures, and more specifically, a water-swellable round piece cast using a concrete formwork. Concrete hole (con-hole) that occurs in a part of a concrete structure
This invention relates to water-swellable round pieces used for repairing.

[Prior art and problems] When concrete structures are cast using concrete formwork, the concrete formwork is usually held at predetermined intervals using fasteners (separators).
This fastener is embedded in the concrete structure after the concrete formwork is removed. After the concrete formwork is removed, the end of the round separator, which is a fastener, is exposed to a part of the concrete structure and a hole is created around the end. Water seepage from the area causes rusting of the round separator and reinforcing bars, and deterioration of the concrete structure. In recent years, this trend has become even more intense due to the increased use of sea sand in concrete.

For this reason, guidance is being strengthened to completely shut off water by making the hole as large as possible and completely repairing the hole.

As shown in Fig. 6, the method for repairing a connecting hole is to apply two-component type epoxy putty 11 to a mortar round piece (or plastic round piece) 10 that matches the shape of the connecting hole 9, and push it into the connecting hole. It is common to fix the round pieces and stop water, and in some cases, finish the outer wall surface with mortar or the like.

However, this method has the following drawbacks.
Due to concrete shrinkage, vibration, etc., the joint surfaces of the concrete holes separate, causing water leakage. Mixing the putty on-site is time-consuming and can result in mixing errors. Even with one-component putty, depending on the amount applied to the round pieces, it may not be possible to seal the hole, and if it is too much, it will overflow, degrading the appearance of the wall surface, making the construction work complicated and variable. In the case of mortar round pieces, there are variations in shape due to shrinkage, and the molding time is long, resulting in poor productivity.

Therefore, as shown in Figure 7, insert rubber into the contact hole 9.
A plastic round piece (not shown) with a water-swellable rubber gasket 12 inserted and matched to the screw thread of the round piece.
There is also a way to repair the water stop by screwing it in.
It is recognized that it is difficult to manufacture round pieces that match the threads of the round separator, and that there are drawbacks to the construction of screwing in on-site.

Also, as shown in Figure 8, a method has begun to be taken in which concrete is poured by attaching rubber or a water-swellable rubber ring 13 to the round separator 8 instead of the cone hole 9 to prevent water from seeping through the round separator. However, the hole still needs to be repaired, and the rust in the part closer to the outer wall than the round separation will flow to the surface and stain the outer wall.

Furthermore, in Japanese Patent Application Laid-open No. 53-98128, the inner circumferential surface
An embedding round piece whose inner bottom surface is partially or completely covered with a water-swellable substance and a water-wettable cap body that fits over the tip of a round separator have been proposed. The pieces are difficult to manufacture, and the use of a separate cap body together with a round piece for embedding poses problems such as complicated work. Regarding the water-swelling substances that should be used, the above publication does not disclose any specific compounds, and only generally discloses that water-swellable substances can be used. There are always a variety of options available, and not all of them are suitable for mounting round pieces.

The present invention solves these problems by providing a round piece that is easy to install at the manufacturing site and has a completely waterproof effect.

[Means for Solving the Problems] The water-swellable round piece of the present invention is made by integrally molding a round piece body 1 and a tip portion 2 made of water-swellable rubber provided at the tip of the round piece body 1. and the tip 2
An insertion hole 3 is provided in the center into which the tip of a separator, which is a fastener for concrete formwork, can be inserted.

In addition, the size of the separator tip (diameter size)
is approximately constant, so the size (diameter size) of the insertion hole 3 in the water-swellable round piece of the present invention
is preferably slightly smaller than the diameter of the separator tip so that the separator tip (round separator tip) can be easily inserted and difficult to fall off.

Figure 1 shows an example of the water-swellable round piece of the present invention, in which water-swellable rubber 2 is integrally molded on the round piece body 1, and an insertion hole 3 is slightly smaller than the tip of the round separator.
It is an open one. The water-swellable round piece shown in FIG. 2 has a threaded insertion hole 3 formed in a water-swellable rubber portion 2 that is similarly molded integrally with the main body 1. These round pieces can be easily inserted into the tip of the separator due to their rubber elasticity, and are difficult to fall off, and are also highly waterproof due to their water-swellable rubber.

When the round piece body and the water-swellable rubber portion are integrally molded in this manner, it is preferable to provide an undercut or the like to ensure integration.

In FIG. 3, a water-swellable rubber ring 4 is attached to the upper part of the round piece in order to further improve the water-stopping effect. This ring swells when it first comes into contact with water entering from the outside, and its swelling pressure serves to fix the round piece. This prevents the round pieces from lifting up due to expansion of the water-swellable rubber at the bottom.

Further, as shown in FIG. 4, in order to prevent the round pieces from falling off, it is also advisable to embed a magnet 5 deep inside the insertion hole 3 of the round piece.

Water-swellable rubber performs a primary water stop due to its rubber elasticity, and then completely stops water by expanding upon contact with water. However, in the case of underground structures with high water pressure, water-swellable rubber Water leakage may occur before the water expands. In such a case, as shown in Figure 5, make a recess 6 in the body of the round piece and apply water-swellable sealant,
It is also possible to apply epoxy putty and embed it, and use the adhesive strength of such sealant and putty to completely seal off the initial water.

Preferred water-swellable rubbers of the present invention are:
The water-swellable polyurethane-containing flexible material is particularly preferred, and a flexible material comprising a mixture of water-swellable polyurethane and natural rubber, synthetic rubber, recycled rubber, etc. is particularly preferred.

In order to manufacture the water-swellable round pieces of the present invention, the round piece body and the water-swellable rubber molded article may be separately molded and then glued together using an adhesive, but this is a complicated process and is not very productive. It is also possible to create an integrated molded product by placing a water-swellable rubber molded product in an injection mold and performing plastic injection molding.
High pressure and high temperatures during injection molding cause deterioration of the rubber, which is undesirable. Therefore, it is preferable to use a resin that can be molded with low injection pressure and raw material temperature, and that requires a short molding time.

Polyurethane resins are examples of resins that meet these conditions, and it is preferable to use them to manufacture the round piece bodies, but the following polyurethane resins are particularly suitable for manufacturing the round pieces of the present invention.

That is, a polyol obtained by adding 1 to 5 moles of alkylene oxide per active hydrogen to an amine compound such as monoethanolamine, ethylene diamine, diaminodiphenylmethane, diethylene triamine, hexamethylene diamine, etc.
A polyurethane resin made by mixing and stirring polyisocyanate with a material diluted with a plasticizer (dibutyl phthalate, dioctyl phthalate, xylene, petroleum solvent, etc.) to lower the viscosity, has a low viscosity and can be poured into a mold in 20 seconds without foaming. - Can be demolded in 1 minute,
An integrally molded product with rubber can be easily obtained.

Amine-based polyols generally have a high viscosity and are difficult to handle, but by diluting them with a plasticizer, they can be made to have a low viscosity of 10-300 cps, and the reaction time is fast, and there is no bleeding or diffusion of the diluent from the polyurethane resin. Since a high-quality molded product can be obtained, it is preferable as a raw material for the round piece body of the present invention.

In addition, unlike injection molding or RIM molding, this molding method has the advantage of being able to be injected under normal pressure and requiring only weak mold material strength. It is possible to create integrally molded products.

It is also possible to use the same molding method to inject cement mortar instead of polyurethane resin, but this is not preferred because it has the fatal drawback of taking a long time to harden and is also prone to chipping due to poor adhesion to the rubber ring. . Furthermore, instead of polyurethane resin, thermosetting resins such as epoxy resins and unsaturated polyester resins can be injected, but epoxy resins have drawbacks such as high viscosity, slow reaction, and curing shrinkage, and unsaturated polyester resins Resins have drawbacks such as odor and large curing shrinkage.

Furthermore, if the water-swellable rubber absorbs water and releases little water even in the dry state, so-called irreversible water-swellable rubber, it is possible to obtain round pieces that are highly watertight and harden even in the dry state. Some of these irreversible water-swellable rubbers include water-swellable urethane resins, rubbers, and cement.

[Marukoma production example] Polyol (OHV760) 40 with 4 moles of propylene oxide added to 1 mole of ethylenediamine
1 part was mixed and dissolved in 60 parts of octyl adipate.
The viscosity of this product was 70 cps. 100 parts of this polyol and crude MD1 with an NCO% of 30.5 (viscosity
250cps) was mixed and poured into a mold. Approximately 1 at room temperature
The mold could be demolded in minutes, and a round piece was obtained that was integrally molded in perfect contact with the water-swellable rubber.

[Effects of the invention] The water-swellable round piece of this invention can be easily installed at the construction site because it only needs to be inserted into the connecting hole from its tip.Moreover, it has an insertion hole at the tip. Since the tip of the round separator is inserted into the insertion hole, the water-stopping effect can be made even more complete.

[Brief explanation of the drawing]

1, 2, 3, 4, and 5 are cross-sectional views showing examples of the water-swellable round pieces of the present invention, and FIGS. 6, 7, and 8 are FIG. 3 is a sectional view showing a conventional construction state. 1... Round piece body, 2... Water-swellable rubber, 3...
Insertion hole, 4...Water-swellable rubber ring, 5...
... Magnet, 6 ... Hollow, 7 ... Concrete structure, 8 ... Round separation, 9 ... Connection hole, 10 ... Round piece, 11 ... Putty, 12 ... Packing, 13 ...
Round separation.

Claims (1)

[Scope of utility model registration request] A round piece body 1 and a tip portion 2 made of water-swellable rubber provided at the tip of the round piece body 1 are integrally molded, and a concrete formwork fastener is provided at the center of the tip portion 2. A water-swellable round piece provided with an insertion hole 3 into which a separator tip can be inserted.