JP2003226861A - Water-cutting-off agent and water-cutting-off method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a water-cutting-off agent capable of surely blocking cracks without applying pressure to concrete structures as a water-cutting-off material used for a tube injection type water-cutting-off method and excellent in endurance. <P>SOLUTION: The water-cutting-off agent comprises a two pack reaction type polyurethane elastomer composed of a liquid A comprising a polyol as a main component and a liquid B comprising an isocyanate as a main component, and viscosities of the liquid A and the liquid B are both ≤200 mPa s/25°C and hardness (Shore A) of reaction cured product of the liquid A with the liquid B is 30-80. The water-cutting-off method comprises previously embedding an injecting tube into a concrete structure and injecting the water-cutting-off agent through the injecting tube into the concrete structure when water leaks or has a possibility of leakage of water to stop water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water-stopping chemical solution and a water-stopping method. More specifically, it relates to a method for stopping leakage of water from a concrete structure by injecting a chemical liquid for water stoppage into the concrete structure through an injection tube (tube-injection-type water-stopping method), particularly for roads and railways. The present invention relates to a water-stopping chemical solution suitable for use in a site where concrete such as a tunnel arch is easily broken by the foaming pressure of an injected chemical solution, and a water-stopping method using the same.

[0002]

2. Description of the Related Art Concrete structures are poorly constructed, and voids are created in the structures when external forces such as temperature and humidity changes, drying shrinkage, alkaline aggregate reaction, or earthquakes act. Generate cracks. Conventionally, in order to carry out this kind of repair, a method of filling various cracks with various grout materials is generally taken, and water glass or hydration reaction type urethane is used as the grout material. .

[0003]

However, water glass and hydration reaction type urethane lack durability and cannot obtain a semi-permanent water blocking effect. Then, JP-A-61-1960
In Japanese Patent Publication No. 70, a hard urethane foam which has waterproofness and durability and foams by a factor of 2 to 120 is proposed. But,
Urethane foam is subjected to a very large foaming pressure when foamed and hardened, and cannot be used for concrete structures that are vulnerable to back pressure, such as arches of tunnels such as roads and railways, and fragile parts.

Further, the water-stopping chemical used in the water-stopping method for concrete structures has a high viscosity, so that it is difficult to surely penetrate into fine cracks.

The present invention has been made in order to solve such problems, and in particular, as a water-stopping material used in a tube-filling type water-stopping construction method, pressure is not applied to a concrete structure and cracks and the like are surely performed. The purpose of the present invention is to provide a water-stopping chemical solution that is blocked and has excellent durability.

[0006]

[Means for Solving the Problems] A water-stopping chemical solution of the present invention which achieves the above object is a two-component reactive polyurethane comprising a solution A containing a polyol as a main component and a solution B containing an isocyanate as a main component. Water stopping chemicals of A and B
The viscosity of the liquid is 200 mPa · s / 25 ° C. or less, and the hardness (Shore A) of the reaction cured product of liquid A and liquid B is 30.
It is characterized by being an elastic elastomer of ˜80.

In the water-stopping chemical liquid of the present invention, liquid A and liquid B
It is preferable that the time from the mixing of the liquids to the curing is 10 minutes or more.

Further, in the water-stopping method of the present invention, an injection tube is embedded in a concrete structure in advance, and when the water leaks or there is a risk of water leakage, the water-stopping chemical solution is passed through the injection tube to the concrete structure. Water is injected into the water to stop it.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the polyol used in the liquid A in the water-stopping chemical solution of the present invention include dihydric alcohols such as 1,3-butanediol, 1,4-butanediol, and 1,6-hexanediol. , Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol,
Glycerin, trimethylolpropane, mono-, di- or triethanolamine, diglycerin, sorbitol,
Propylene oxide, either alone or in a mixture such as sucrose,
Examples include polyols obtained by addition-polymerizing alkylene oxides such as ethylene oxide, and castor oil. Further, various polyester polyols obtained by dehydration condensation reaction of dibasic acids such as adipic acid and phthalic anhydride with glycols and triols such as ethylene glycol, diethylene glycol and trimethylolpropane, and lactone series obtained by ring-opening polymerization of ε-caprolactam. Polyester polyols, other polycarbonate diols, acrylic polyols, polybutadiene-based polyols, phenol-based polyols, radical-polymerized vinyl-based monomers such as acrylonitrile and styrene in polyols, and polymers obtained by dispersing and dissolving these polymers in polyols. Polytetramethylene glycol obtained by cationic polymerization of polyol or tetrahydrofuran, or modification by addition polymerization of alkylene oxide Estriol and the like. The molecular weight of these polyols is preferably 40 to 20,000.

Among the above polyols, in order to suppress the reaction with water in the concrete structure to form a non-foaming elastic elastomer, a propylene oxide addition-polymerized polyol obtained by addition polymerization using only propylene oxide as an alkylene oxide, and a polybutadiene. Hydrophobic polyols such as polyols are preferably used.

The isocyanate used in the liquid B in the water-stopping chemical solution of the present invention includes, for example, diphenylmethane diisocyanate containing isomers such as 2,2-, 2,4-, and 4,4-.
Polymethylene polyphenyl polyisocyanate, tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, singly or in a mixture, dimer, trimer or carbodiimide modified isocyanate of these isocyanates, Further, a urethane prepolymer obtained by previously reacting a part of the above-mentioned polyol and isocyanate is used.

To the solutions A and B, a catalyst for reacting a polyol with an isocyanate and a viscosity modifier for decreasing the viscosity can be added.

As the catalyst, a catalyst usually used for the reaction of urethane resin is used. Examples thereof include amine catalysts such as dimethyloctylamine, dimethyllaurylamine, morpholine, piperazine, triethylenediamine, bisdimethylaminoethyl ether and imidazole, and metal catalysts such as dibutyltin laurate.

As the viscosity modifier, a plasticizer or a viscosity reducer usually used for urethane resins is used. For example,
Dialkyl esters of dibasic acids such as dioctyl adipate, diisononyl adipate and dioctyl phthalate. Monoalkyl esters of glycol ethers such as methyl cellosolve, ethyl cellosolve, propylene glycol methyl ether, ethyl carbitol and butyl carbitol. Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol,
Examples thereof include dialkyl esters of glycols such as dipropylene glycol, alkylene carbonates such as propylene carbonate, cyclic ethers such as tetrahydrofuran and dioxane, cyclic esters such as γ-butyl lactone and ε-caprolactam, and hydrocarbons such as paraffin. Further, in order to impart flame retardancy in addition to viscosity reduction, a phosphoric acid ester such as tributyl phosphate, a halogenated phosphoric acid ester such as tris monochloroisopropyl phosphate, etc. are used.

If necessary, a colorant, an antiaging agent, a surfactant, etc. may be added to the solutions A and B.

The respective viscosities of the liquids A and B are 200 mPa · s / 2 so as to surely penetrate into fine cracks.
It is adjusted to 5 ° C or lower. Viscosity is 200 mPa · s / 25
If the temperature exceeds ℃, the chemical liquid cannot be surely permeated into the fine cracks unless the injection pressure is increased, so that the concrete pressure may be damaged by the injection pressure, which is not preferable.

Liquid A containing polyol as a main component and liquid B containing isocyanate as a main component are two-component reactive polyurethanes which react to each other at room temperature to form polyurethane by mixing the two. The curing time from the mixing of the two liquids to the gelation of lack of fluidity is usually adjusted within the range of 10 minutes to 2 hours. If the gelation is too fast, it becomes difficult to permeate into the fine cracks, and if the gelation is too slow, it is likely to be affected by water in the voids, which is not preferable.

The reaction cured products of the liquids A and B are elastic elastomers having a hardness (Shore A) of 30 to 80. Since the reaction-cured product is an elastic elastomer in this way, it does not apply pressure to the concrete body with foaming pressure, unlike hard urethane foam. Therefore, it does not damage the concrete structure. Here, if the hardness (Shore A) is less than 30, it is too soft and deforms due to water pressure or the like, so that a reliable waterproofing effect cannot be obtained. On the other hand, if the hardness (Shore A) exceeds 80, it is not preferable because it is too hard and brittle.

The mixing ratio of the liquid A and the liquid B is usually 1 by weight.
It is preferably adjusted within the range of / 3 to 3/1.

In the water-stopping method of the present invention using the above-described water-stopping chemicals, the injection tube is embedded when a concrete structure such as a tunnel arch portion is constructed, and a splice portion, a junker portion, a cracked portion, etc. When water leaks from a part having poor water tightness or there is a risk of water leak, the water blocking chemical is injected into the concrete structure through the injection tube to stop water.

As described above, since the water-stopping chemical of the present invention has a low viscosity, the chemical can be surely penetrated into fine cracks in the concrete structure without increasing the injection pressure. The water-stopping chemical injected through the injection tube is solidified in the concrete structure, but since the cured product of the water-stopping chemical is a non-foaming elastic elastomer as described above, the foaming pressure during solidification Therefore, it is necessary to adopt a known method as a method of mixing the liquids A and B, which reliably block the cracks without damaging the concrete structure and exert water-stopping property, and inject them into the injection tube. You can For example, A
Liquid A and liquid B can be put in separate tanks, and liquid A and liquid B can be uniformly mixed and injected through a static mixer using a proportional mixing type pump capable of controlling the injection amount, pressure, mixing ratio and the like. Alternatively, it is possible to inject a mixture of the liquid A and the liquid B in advance uniformly with a single liquid pump.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Liquids A and B of Examples 1 to 3 and Comparative Examples 1 and 2 were prepared according to the formulations shown in Table 1 below. Examples 1 to 3 are the elastic elastomer water stop chemicals of the present invention,
Comparative Examples 1 and 2 are conventional rigid foam water-stopping chemicals.

The polyols, isocyanates, viscosity modifiers, catalysts and silicone foam stabilizers in the table are as follows.

(Polyol) Castor oil D: castor oil polyol produced by Ito Oil Co., Ltd. Hydroxyl value = 160 mg KOH / g G1000: Polyether polyol obtained by adding propylene oxide to glycerin. Hydroxyl value = 168mgKO
H / g A480: Polyether polyol obtained by adding propylene oxide to monoethanolamine. Hydroxyl value = 480
mgKOH / g D400: A polyether polyol obtained by adding propylene oxide to propylene glycol. Hydroxyl value = 280
mgKOH / g R15HT: Idemitsu Petrochemical Co., Ltd. product, polybutadiene polyol. Hydroxyl value = 106 mg KOH / g.

(Isocyanate) Cosmonate M50:
Mitsui Chemicals, Inc. product, Polymeric MDI (Polymethylene polyphenyl polyisocyanate) Prepolymer: 1000 g of Cosmonate M50 and polyol of 480 mg KOH / g of hydroxyl value 480 mgKOH / g obtained by adding propylene oxide to glycerin as a polyol.
Polyol 8 having a hydroxyl value of 280 mgKOH / g obtained by adding propylene oxide to 5 g and propylene glycol
A urethane prepolymer having a free isocyanate group of 25.9%, obtained by reacting a polyol mixed with 2.5 g.

(Viscosity modifier) DINA: diisononyl adipate TMCPP: Tris monochloro isopropyl phosphate DBP: dibutyl phthalate.

(Catalyst) TEDA L33: product of Tosoh Corporation, triethylenediamine / dipropylene glycol =
1/2 (weight ratio) LDA: lauryl dimethylamine.

(Silicone foam stabilizer) Silicone SH19
0: Toray Silicone Co., Ltd. product.

The viscosities of solutions A and B in Table 1 were measured according to JIS K6833.

The prepared solutions A and B of Examples 1 to 3 and Comparative Examples 1 and 2 were mixed at the compounding ratios shown in Table 1, and a free foaming test, a restraining foaming test and a water stopping test were conducted. . Each test method is as follows.

Free foaming test: Solution A and solution B were uniformly mixed and adjusted to 20 ° C. Next, the liquid A and the liquid B were uniformly mixed with a spatula at a predetermined mixing ratio. The gel time was the curing time from the start of mixing until the fluidity disappeared. The volume after curing was divided by the volume at the start of mixing to obtain the expansion ratio.

Constrained foaming test: Solution A and solution B were uniformly mixed and adjusted to 20 ° C. Next, the liquid A and the liquid B were uniformly mixed with a spatula at a predetermined mixing ratio. In the case of Examples 1 to 3, the mixture was filled in a mold of 5φ × 10 cm, and in the case of Comparative Examples 1 and 2, ½ amount of the mold of 5φ × 10 cm was injected, and the pressure applied to the lid. Is measured
The foaming pressure was used. After curing, remove the cured product from the mold, 2
After curing for 7 days at 0 ° C., the hardness of the side surface of the cured product was measured with a Shore A hardness meter. The appearance was judged by pushing the cured product with a finger.

Water stop test: 15 as in the constrained foaming test.
Using a mold of (length) × 15 (width) × 1 (thickness) cm, a cured product was prepared. According to JIS A 6909 water permeability test B method, water permeability was measured and it was judged whether or not there was water stopping property.

[0035]

[Table 1]

[0036]

As described above, the water-stopping chemical solution of the present invention has a low viscosity, and since the reaction-cured product is an elastic elastomer, the chemical solution can surely penetrate into fine cracks. Moreover, since there is no foaming pressure, the concrete body is not damaged.

Claims (3)

[Claims] 1. A water-stopping chemical for a two-component reactive polyurethane comprising a liquid A containing a polyol as a main component and a liquid B containing an isocyanate as a main component, wherein the viscosities of the liquids A and B are each 200 mPa. A water-stopping chemical liquid which is s / 25 ° C. or lower and is an elastic elastomer having a hardness (Shore A) of a reaction cured product of liquid A and liquid B of 30 to 80. 2. The water-stopping chemical liquid according to claim 1, wherein the time from the mixing of the liquids A and B until hardening is 10 minutes or more. 3. A water blocking chemical according to claim 1 or 2 is injected into the concrete structure through an injection tube when the water is leaked or there is a risk of water leakage when the injection tube is embedded in the concrete structure in advance. The water-stopping method is characterized by stopping the water.