JPH0258672A - Static crushing agent - Google Patents

Abstract

PURPOSE:To facilitate regulation of a crack occurring time and to sharply reduce the occurrence of gun phenomenon by a method wherein a crashing agent is formed in the shape of a grain, grains being given % of all grains and having a hydration reaction speed higher than that of remaining grains are contained in a container capable of crashing. CONSTITUTION:At least two kinds of grains consisting mainly of quick lime having a Blaine's value of 2000-8000cm<2>/g and the shape of an agent being a grain of approximate 1-30mm and a hydration reaction speed of 5-50% of all grains being higher than that of remaining grains and different hydration speeds are mixed together. The mixture is contained in a container capable of easily crashing in a way that the mixture is charged in a hole formed with a paper, a non-cloth, a plastic film, to thrust it by means of a loading stick, and this produces a static crashing agent. This constitution forms the crushing agent in a granular shape to sharply reduce injection, and enables regulation of a crushing time of a crushing substance in a way that grains having different hydration speeds are coexistent with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a crushing agent for statically crushing brittle objects such as concrete and rocks.

C. Prior Art] Conventionally, as a crushing agent for statically crushing concrete, rocks, etc., a mixed powder containing calcium oxide (quicklime) as a main component is known. Furthermore, expansible tablets are also known, which are molded granules obtained by mixing calcium oxide powder as a main component and a reaction regulating substance in powder form, and then compression molding the mixture. When crushing concrete or rocks, any of these requires adding water to cause a reaction with calcium oxide, which is the main component of the crushing agent. If the water and crushing agent are in granular form, the method is to pour the crushing agent into the concrete or rock to be crushed into a hole that has been prepared for filling the concrete or rock, and then pour the water later.
Another known method is to store the material in advance in a container that is crushable and permeable to water, and then immerses it in water in a bucket or the like at the site and then fills it into the hole.

[Problem that the invention seeks to solve]

In crushing concrete and rocks using the above method,
The reaction between calcium oxide, which is the main component of the crushing agent, and added water generates heat, increasing the water vapor pressure within the pores and causing the agent itself to protrude (gun phenomenon). With timed crushing type (cracks occur in concrete within 3 hours), depending on the conditions at the time of crushing (air temperature, pore size, water temperature, etc.), cracks may occur within a few minutes, so this crack generation time can be adjusted arbitrarily. It was difficult.

C. Means for Solving Problems] In order to deal with these problems, the present inventors have made various efforts, and as a result, have achieved the present invention.

In other words, the present invention provides a static crushing agent containing quicklime as a main component, which has grains with a dosage form of about 30++ u++ and whose hydration reaction rate of 5 to 50% of the whole grains is faster than that of the remaining grains. This is a static crushing agent that is made by storing the liquid in a crushable container.

The quicklime used in the present invention has a Blaine value of 2,000 to 8.
, 000 cJ/g, and is usually called hard calcined quicklime.

The hydration reaction rate of quicklime with water can be adjusted in various ways. For example, it can be easily adjusted by increasing the Blaine value of quicklime or by mixing a reaction regulating substance.

Among the typical examples of reaction regulating substances, those that speed up the hydration reaction rate include aluminacemen 1-1 ruthorum chloride, and those that slow it down include portland cement, gypsum, and alkali of boric acid. There are earth salts, etc.

The shape of the static crushing agent of the present invention needs to be granular with a size of 1 to 30 m+++. This is because by making it into granules, the spouting, which is an effect of the present invention, is drastically reduced.

Appropriate methods for making it into granules include a method of crushing a calcined lump of quicklime, or a method of applying quicklime powder to a molding machine such as a briquenting machine to form molded granules.

In addition, in the present invention, it is necessary to coexist two or more types of grains with different hydration rates, but a method for obtaining such grains is to change the Blaine value of quicklime as described above. It can be arbitrarily adjusted by adding a hydration reaction adjusting substance as appropriate.

Furthermore, when 50% or more of the grains have a fast hydration rate, the remaining grains that have a slow hydration rate have almost no effect on the hydration reaction rate (average) of the whole grain, so proper hydration can be achieved. It is difficult to obtain a high reaction rate, and it is also difficult to adjust the crushing time of the crushed bodies.

It is also important that the granular crushing agent of the present invention be stored in a crushable container. "Fragmentable" means that it can be easily broken by inserting a granular crushing agent into the hole and pushing it in from the top with a wooden or iron ramming rod.

Particles with different hydration reaction rates stored in a crushable container are very effective in keeping the composition and blending ratio stable when filled into the pores. Examples of crushable containers include paper, nonwoven fabric, plastic film, and the like. Moreover, it does not necessarily have to be water permeable.

When two or more types of grains having different hydration reaction rates are separated into layers than when they coexist randomly, a more favorable effect is produced. In addition, 0.1 to II
It is also preferable to mix 5 to 40 parts (based on the granular material) of III+ sand to enhance the effect.

〔Effect of the invention〕

(1) When crushing concrete or rock in a short period of time, the crack generation time can be easily adjusted between about 5 and 180 minutes.

(2) Dramatically reduce the occurrence of gunshot phenomena.

〔Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples and Comparative Examples 90 parts by weight of quicklime powder (Blaine value 6.OOM/g), 10 parts by weight of alumina cement, and 2 parts by weight of calcium chloride were thoroughly mixed and compression-molded using a briquenting machine to obtain molded granules (bulk density 2.55 g/Cf1. Particle size, breadth 7
An almond-shaped product with a major diameter of 14 mm was obtained.

The obtained molded grains were put into a concrete mixer (50ρ) and deburred, and the hydration reaction rate was evaluated at 20"C and was found to be 2 minutes (hereinafter referred to as A grains).

In the above formulation, 10 parts by weight of gypsum was added instead of alumina cement, and the same molded particles were obtained by molding without adding calcium chloride. The hydration reaction rate did not reach 95°C (hereinafter referred to as B grains).

The mixing ratio of A grains and B grains was set as shown in Table 1, and the concrete cracking time and the occurrence rate of the Oko Teppo phenomenon were evaluated.

A grain again! :IF, when grains are layered and 0.4
A total of 61 mm for those mixed with 30 parts of sand
I valued it.

What?1? , Concrete 1 has a compressive strength of 300 kg/cf
+, 40m in the center with 600 body angle...φX500mm
A total of 2 grains of A grain, 13 grains, and sand were placed in the specimen with a long hole.
00 g/piece and housed in a 5.30 mmφ x 200 length nylon nonwoven tube. In addition, the incidence of gunshot phenomenon was calculated using water injected into a cylindrical pipe (height: 300 mm), with the inner tube being a PVC pipe with an inner diameter of 40 mm and a wall thickness of 4 m111, and the outer tube being a steel pipe with an inner diameter of 49+n+n and a wall thickness of 6 mm. Two bottles of the agent were filled and evaluated.

Margin below

Claims (1)

[Claims] In the static crushing agent whose main ingredient is quicklime, the dosage form is 1.
A static crushing agent made by storing particles in a crushable container, which are particles approximately 30 mm in size and have a faster hydration reaction rate of 5 to 50% of the whole particles than the rest of the particles.