JPS599591B2 - Boutiyou Seisui Grout no Seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an expandable water-stop grout.

Conventionally, in order to improve shrinkage after curing, which is a drawback of water-stop grouts made of water glass and cement paste, it has been known to generate expandable grouts by adding metal powder to generate hydrogen bubbles.

However, even if this grout is applied in a poorly ventilated place such as a tunnel, there is a risk of explosion due to hydrogen gas, so it cannot be used, or it must be installed as explosion-proof equipment, and it also has uniform expansion properties. In order to achieve this, the grout mixing had the disadvantage of requiring sufficient care. The present invention aims to provide a method for producing a water-stop grout that solves these drawbacks and is quick-setting, quick-hardening, and expandable. The feature of the present invention is that expansion occurs too quickly, so even if it is included in cement and the expansion rate is measured,
Adding an expanding material to the cement that does not cause expansion phenomenon
Cement containing 50% by weight is used.

In other words, even if the present grout contains a cement expanding agent, which has conventionally been used for the purpose of preventing cement shrinkage, expansion mainly occurs after the water glass cement has hardened. It is destroyed and the intended purpose cannot be achieved.

In the present invention, the strength of the cement water glass hardened body is at least 10 kg/C! Use cement containing an expanding agent that will expand sufficiently during the development of about It. The expanding material having such properties is mainly composed of calcium oxide and/or magnesium oxide, and specifically contains at least 50% by weight of calcium oxide and/or magnesium oxide, preferably 80% by weight of calcium oxide and/or magnesium oxide. can be used. The fineness of the expanding material is related to the setting and hardening of water glass cement, and the plain value is 4.
000 to 7000 ciV9 is preferred.

The cement contains such an expanding agent in an amount of 5 to 50% by weight, preferably 10 to 30% by weight.

If the amount of the expanding agent is less than 5% by weight, it will not be effective, and if it exceeds 50% by weight, the effect of imparting expandability will not be significantly improved, and the strength of the cured product will decrease. The ratio of water glass to cement is 0.01 to 10 water glass to the cement weight.
Although the amount can be arbitrarily selected depending on the site situation, the amount usually used is 0.5 to 3 times. Portland cement and mixed cement can be used as cement.

The grout of the present invention as described above can fully achieve the intended purpose, but in addition, the higher fatty acid coating is expanded in order to cause the expansion agent to expand at a time suitable for curing the grout and to obtain a high-strength cured product. The timing of expansion of the expandable material is controlled by forming it on the surface of the material or by adding silicate.

As a method for forming a film of higher fatty acids, for example, one or more of stearic acid, oleic acid, and their salts 1 is added in an amount of 0.1 to 10% by weight based on the expanding material. 30℃ or higher and lower than the boiling point of the higher fatty acid, preferably 8℃.
Heat at 0-130°C for 5-30 minutes.

As the silicate, sodium silicate, potassium silicate, barium silicate, etc. can be used, and the amount thereof can be selected within the range of 0.001 to 1% by weight based on the expanding material. It is sufficient to simply blend the silicate. The effects of the grout of the present invention are as follows.

1. It has great strength after curing and can prevent shrinkage.

2. Complete water stop is possible.

3. It is safe because it does not generate flammable gas such as hydrogen gas.

4. The grout has good filling properties and can be injected into minute cracks using expansion pressure.

The present invention will be explained below with reference to Examples.

Example 1 Calcium carbonate having the chemical components shown in Table 1 was heated to 1300°C.
After baking for 2 hours, the product was ground in a pot mill to obtain a Blaine value of 4000 d/9, and this was added as an alternative to ordinary Portland cement at 10, 20, and 30% by weight, resulting in a water/cement ratio of 100% by weight. It was made into a paste.

Separately from this paste 500CC, 500CC of JIS No. 3 water glass mixed with the same volume of water was mixed, and 4
The sample was placed in a ×4 × 160ffL mold, and the compressive strength, expansion rate, and gel time were measured. The results are shown in Table 2. The expansion rate was measured by the comparator method after demolding the mold for 1 hour and lengthening the base.

The expansion rate of the paste without water glass was measured in the same manner, but no expansion was observed. Gel time was expressed as the time when fluidity disappeared.

Next, grout with each expansion agent addition rate was applied to an iron pipe with a diameter of 5 degrees and a length of 1 meter and a length of 30C! ! Fill it up to L,
One day later, water was poured into the remaining part and the presence or absence of water leakage was measured.

As a result, water leakage was observed in the sample without the addition of expansion material, but
It was not observed in other samples. Also, instead of the above-mentioned expanding material mainly composed of calcium oxide, the purity is 95% by weight?
When magnesium oxide was similarly tested using a product fired in an electric furnace at 1350°C, the results were almost the same as in Table 2.

Example 2 Daiichi Cement iron ore slag (plain 5040, and
Using each grout, the water-stop properties were measured in the same manner as in Example 1. Sample 5≦d/9) (water slag) was added to ordinary Portland cement at 80% by weight. The same test as in Example 1 was conducted using a cement in which 0 to 30% by weight of the expanding material mainly composed of calcium oxide of Example 1 was added to the substituted cement.

The results are shown in Table 3. Also, 3 weight for the expansion material? Stearic acid was added and heat treated at 100°C for 20 minutes, and 0.03% by weight of Na2SiF6 was added to the expanding agent, and the above iron ore slag was added in the same proportion to cement. Table 4 shows the results of a similar test using the blended cement.

Claims (1)

[Scope of Claims] 1. In producing a water-stop grout by blending water glass with cement, the cement contains 5 to 50% by weight of an expanding agent containing at least 50% by weight of calcium oxide and/or magnesium oxide. 1. A method for producing an expandable water-stop grout, characterized in that it uses cement that has been made to withstand water. 2. A method for producing an expandable water-stop grout according to the specific invention, characterized in that an inorganic silicofluoride is further blended or the expanding material is coated with a higher fatty acid or a salt thereof.