JPS5879072A - Crushing agent - Google Patents

Abstract

PURPOSE:A crushing agent, prepared by incorporating a quick setting material consisting of amorphous calcium aluminate and an inorganic sulfate and cement as a principal component, and capable of crushing a brittle material in a short time even in a cold district. CONSTITUTION:A crushing agent prepared by incorporating 100pts.wt. principal component containing (A) a mixture containing amorphous calcium aluminate with an inorganic sulfate, e.g. anhydrous gypsum or sodium sulfate, at preferably 1.5-2 weight ratio and a cement, usually portland cement, at (50-80):(50- 20) weight ratio with (B) 3pts.wt. or less dispersing agent, e.g. lignin sulfonate or water-soluble melamine resin, and (C) 5pts.wt. or less setting retarder, e.g. sodium carbonate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crushing agent used when filling a hole in a brittle object such as rock or concrete and crushing it using the expansion pressure. The purpose is to enable crushing work.

Conventionally, as this type of crushing agent, for example, Japanese Patent Application Laid-Open No. 56-6
As described in Japanese Patent No. 7059, one containing quicklime has been proposed. However, with this crushing agent, 5
In cold regions below ℃, crushing may require a long time,
Furthermore, the rate of water utilization is very fast, and when mixed with water, it rapidly generates heat and the slurry squirts out of the inlet, making it impossible to crush it efficiently or at all. .

As a result of various studies aimed at resolving the drawbacks of such crushed materials mainly composed of quicklime, the inventors of the present invention have developed a material consisting of cement and a mixture whose main components are amorphous calcium calcium aluminate and inorganic sulfate. The present invention has been completed based on the discovery that the use of C. as the main material enables sufficient crushing even in cold regions of 5° C. or lower.

That is, the present invention provides amorphous calcium aluminate,
This crushing agent contains 3 parts or less of a water reducing agent and 5 parts or less of a setting retarder per 100 parts of a main material containing an inorganic sulfate and cement.

The present invention will be explained in detail below.

Amorphous calcium aluminate is 120aO・741
g03.50aO*A]403, OaO@Al2O3,
110aO・7 A1203sOaF□, 50aO'!
I A1203sOa? It has a composition ratio of 2, etc., and in the presence of inorganic sulfates, it quickly undergoes a hydration reaction to produce calcium sulfoaluminate hydrate (ettringite), thereby imparting expansion pressure to brittle objects. It is a necessary ingredient for Such amorphous calcium aluminate can be obtained by mixing lime and alumina almost stoichiometrically so as to have the above composition, heating and melting the mixture, and then rapidly cooling the mixture.

Inorganic sulfate is 1 similar to amorphous calcium aluminate.
This book is necessary as a component to produce ettringite, and anhydrite, dihydrate gypsum, hemihydrate gypsum, sodium sulfate, etc. are used. The mixing ratio of amorphous calcium aluminate and inorganic sulfate is 1 for the former and 0.5 to 3 for the latter by weight.
, especially books with a rating of 1.5 to 2 are preferred. It is convenient to use amorphous calcium aluminate and inorganic sulfate as a mixture (hereinafter referred to as a rapid hardening material), and there are commercially available products of this mixture. The particle size of the rapidly hardening material is preferably 2.5 m or less, and the Blaine specific surface area is preferably 1000 to 7000 cm2/Jil.If it is too fine, the fluidity will decrease and the water use reaction will be too fast, and if it is too coarse, there will be no problems with fluidity. However, this is not preferable because it causes material separation and, as a result, reduces the expansion pressure.

As the cement, one or more types of cement are used, such as ordinary, early strength, and ultra early strength Portland cement, mixed cement containing silica, blast furnace slag, fly ash, etc., and alumina cement. Usually, Portland cement is used because the effect does not change much depending on the type.

The ratio of the main material, rapid hardening wood, to cement is 30-95, especially 50-80, and the latter is 70-5, especially 50-80.
It is preferable to set the number to 120. The reason is that the sudden hardwood 30
% or more than 70% of cement at a low temperature of 5°C or lower.If the main material is water or less than 5% of cement, the heat generated by water utilization is rapid, but the expansion pressure is small to small, resulting in thermal expansion. Although cracks occur due to this, it is not preferable because the cracks do not expand.

The main material according to the present invention as described above does not eject slurry and is suitable for cold regions, and the lower the temperature, the greater the crushing effect. In other words, the brittle object undergoes thermal expansion due to the heat utilization of the crushing agent, and the lower the surface temperature, the greater the temperature difference between it and the vicinity of the perforation wall, which results in a greater crushing effect, and the expansion of the crushing agent itself. Because pressure is added, crushing work in cold regions can be carried out efficiently.

The crushing agent of the present invention further includes a water reducing agent and a setting retarder in the main material. A high-performance water reducing agent is preferable;
Examples include a lignin sulfonate type, a water-soluble melamine resin type, a higher polyhydric alcohol sulfonate type, a β-naphthalene sulfonic acid formalin condensate type, and one or more of these are used. If at most 3 parts of this is added to 100 parts of the main material, the fluidity can be greatly improved and the water ratio can be reduced, and the expansion pressure can be increased to make it even stronger. The effect of adding a water reducing agent is significant up to 2 parts, but since adding more than that does not show a significant effect, the amount was limited to 3 parts or less. As the setting retarder, known tunme is used, and inorganic carbonates such as potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate, organic hydroxycarboxylic acids such as citric acid, tartaric acid, sodium citrate, and sodium gluconate, and their Main material: 100 or more selected from salts
Add at most 5 parts per part. This set retarder is
It is used to suppress the hydration reaction of the main material of the present invention.

Although the addition rate varies slightly depending on the quality of the rapidly hardening material and the aromatic specific surface area, addition of more than 5 parts is not preferable because the pot life becomes too long and, as a result, the expansion pressure becomes low. By using the above-described crushing agent of the present invention, it is possible to prepare a slurry that has excellent fluidity and exhibits a high expansion pressure even at low temperatures, thereby achieving the effect of crushing brittle objects in cold regions in a short time. .

Hereinafter, the present invention will be explained in more detail with reference to examples.

In addition, both parts and parts described in this specification are shown on a weight basis.

Example 1 Blaine specific surface area 1500 tyn2/i with a weight ratio of ■ type anhydrite 1.5 to IK (amorphous calcium alumina having a composition of 120a0.7 Al2O*)
Rapidly hardened material 60% and Brain specific surface area 5200CIL2/
A commercially available water-reducing agent (trade name: "Ultrathin") whose main component is calcium lignin sulfonate is added to 100 parts of the main material consisting of 40% ordinary Portland cement.
2 parts and 1 to 5 parts of a setting retarder (a mixture of 70 parts potassium carbonate, 16 parts sodium gluconate, and 17 parts citric acid) were mixed to prepare a crushing agent. A slurry was prepared by mixing 100 parts of this material with 25 parts of water, and a performance test was conducted on the slurry. The results are shown in Table 1. The brittle object used in the test had a diameter of 15
cIL Height 50cm mortar hardened body (compressive strength 526
K9f/cIL2, tensile strength 52ψ 2), a hole with a diameter of 28 m was penetrated in the center, the slurry was injected into the hole, and the slurry was left at room temperature at 0°C.

Table 1 Example 2 Blaine specific surface area of the rapidly hardened material of Example 1 5000cntV
100 parts of the main material with various ratios of I and ordinary Portland cement were mixed with 2 parts of water reducing agent and 2 parts of setting retarder, and 100 parts of this crushing agent was mixed with 30 parts of water. It was made into a slurry. Table 2 shows the expansion pressure of the slurry for 12 hours at a room temperature of 5°C. The inflation pressure is the inner diameter 36
A steel plate is welded to the bottom of a carbon steel pipe with a height of 600111 for piping, and a paper strain gauge with a gauge length of 10 mm is attached to the center of the surface of the steel pipe in the circumferential and axial directions, and slurry is injected into the steel pipe. It is calculated from the distortion of the steel pipe when it is left unused.

As shown in Table 2 below, the crushing agent of the present invention exhibits a large expansion pressure at low temperatures when the main material has a rapidly hardwood ratio of 30 to 95, especially 50 to 80 o41. I understand the second thing to do.

Example 3 A blasting agent slurry containing 2 parts of the setting retarder of Example 1 was prepared in an area of about 1.5 m" (1 x 1.5 x 171
1) A diameter of 36 cm and a depth of 80 cI applied to the center of rock D.
L hole (when injected and left in an atmosphere of 0 to 3℃,
C
broke into two small pieces.

For comparison, similar low-temperature crushing work was performed using a commercially available crushing agent containing quicklime as the main component, but no crushing occurred even after one week had passed.

Patent applicant: Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] A crushing agent comprising 100 parts by weight of a main material containing amorphous calcium aluminate, inorganic sulfate, and cement, and 3 parts by weight or less of a water reducing agent and 5 parts by weight or less of a setting retarder.