JPS5857485A - Crushing agent for concrete, rock and the like - Google Patents

Abstract

PURPOSE:To provide the titled crushing agent which exhibits an excellent crushing effect in a short time even at a temp. below the freezing point, comprising calcium carbide as a principal ingredient. CONSTITUTION:Industrial calcium carbide particles having a grain size of 6,000 cm<2>/g or below are used. It is preferred to use particles having such a purity that 50-300l of acetylene gas/kg is produced at 20 deg.C under atmospheric pressure when reacted with water. Holes made in a brittle object such as rock or concrete are filled with said calcium carbide particles. Water is added thereto to react the particles with water, whereby the brittle object is crushed. When 5-70pts. hydraulic material such as ultraquick-hardening cement per 100pts. calcium carbide is blended, a crushing agent exhibiting a further excellent effect can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crushing agent for concrete, rock, etc. Conventionally, in order to destroy brittle objects such as rocks and concrete, a method has been proposed in which the holes of the brittle objects are filled with an aqueous slurry mainly composed of quicklime, and the expansion force generated by the water use reaction is utilized. (Japanese Unexamined Patent Publication No. 56-67059).

However, this method has the following drawbacks.

1) It takes a long time of about 10 to 24 hours or more to crush.

2) Since the reaction rate is greatly affected by temperature, 5°
In the practical temperature range of C-30°C, it is necessary to prepare three to four types of materials with different reaction rates.

3) Construction cannot be carried out underwater.

As a result of various studies in order to solve these drawbacks, the inventor of the present invention found that the above drawbacks can be solved by pouring water into a hole made in a brittle calcium carbide object, or by adding water after pouring Carby-P. The heading completes the invention.

That is, the present invention is a crushing agent for concrete, rock, etc., which contains calcium carbide or a hydraulic substance therein.

The calcium carbide used in the present invention is industrially produced and contains impurities, and is usually produced by reacting a mixture of carbonaceous material and quicklime at high temperatures. The purity of calcium carbide is determined by reacting it with water.
It is determined by the amount of acetylene gas generated (pure one is 566 l/edge at 20℃ and 1 atm), but the amount of generation is 5 to 35 Qg, especially those of 50 to 3001 can crush brittle objects in a short time. This is suitable because it can be done. Even if the purity of calcium carbide is high, it does not affect the crushing effect, but since a large amount of acetylene gas is generated during use, it is undesirable from the viewpoint of safety.

If the particle size of calcium carbide is too fine, the reaction will be rapid and calcium carbide may blow out from the pores due to the generation of acetylene gas, so an appropriate particle size is required. Its particle size is 6000 c in one rune value.
rn2fi Jノ, preferably 300, Ocrn2
/f or less is preferable. However, this is not the case if the reaction with water can be appropriately suppressed by adding oil or the like. As long as the maximum diameter can fit into the slurry injection hole, a diameter of several meters can be used.

Conventional materials mainly composed of quicklime had to be used together with a hydraulic substance, but the present invention has the advantage that it can be used without a hydraulic substance. Of course, it goes without saying that the effect will be even greater if used in combination with a hydraulic substance.

Its blending amount is 5 parts per 100 parts of calcium carbide.
A range of 70 parts is effective.

As the hydraulic substance, Portland cement such as ordinary Portland cement or mixed cement, ultra-fast hardening cement, alumina cement, hydraulic calcium aluminate, and hemihydrate gypsum can be used alone or in combination. In particular, ultra-fast-hardening cement is preferable because its reaction rate is well balanced with that of calcium carbide, and since hardening and expansion occur simultaneously, it can be crushed in a short time. The ultra-fast hardening cements are C□, A7CaF2, Cl2A7, CA1C3 where CaO is represented by C1Al2O3 and A is
A1CA2, C3A 3 Ca F2 etc. Calcium aluminate and anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum,
Mixtures with inorganic sulfates such as sodium sulfate, especially the former 1
Examples include mixtures containing the latter in a weight ratio of 0.3 to 5, and cements containing these calcium aluminates and inorganic sulfates. Among these,
It is most preferable to use calcium aluminate as an amorphous material and inorganic sulfate as anhydrous gypsum.

It is not clear why calcium carbide has the effect of destroying concrete, rocks, etc., but because calcium carbide has a high reaction activity, its reaction rate with water is high, and the resulting calcium hydroxide crystals grow quickly. Therefore, it is thought that crushing can be done in a shorter time than with materials using only quicklime, regardless of the reaction temperature. At this time, the crushing effect can be further increased by adding a water reducing agent or a retarding agent as an admixture or by reducing the amount of water.

Examples of water reducing agents include lignin-based ones, higher polyhydric alcohol sulfonate-based ones, oxycarboxylic acid-based ones, alkylaryl sulfonate and hisono high condensate-based ones, and poly-11 oxyethylene alkyl ethers. One or more of the following types are used: those based on polyol composites, those based on water-soluble melamine resins, and those based on β-naphthalene sulfonic acid formalin condensate, and the amount used is the same as calcium carbide or calcium carbide and water. The ratio is about 0.1 to 5 for the mixture of hard substances. In addition, as a retarder, one or more of inorganic carbonates such as potassium carbonate and soda carbonate, organic carboxylic acids such as citric acid, tartaric acid, gluconic acid, malic acid, and lactic acid, or water-soluble salts thereof, calcium carbide or calcium carbide. A ratio of about 0.5 to 10 is used for the mixture of and hydraulic material.

According to the present invention, it exhibits excellent crushing effects even at subzero temperatures in a short time, and can also be used in capsule form using Japanese paper, thin resin film, water-soluble film, etc., especially for underwater crushing work. .

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

Note that all parts and parts in the specification are expressed on a weight basis.

Example 1 Limestone with a diameter of 3Dz was heated to 5°C110'-'0,20°C,
Calcium carbide (acetylene gas generated) was maintained at a temperature of 60°C under each condition.
40 parts of water was added to the 5 leakage pulverized product weighing 7 kg), mixed quickly for 5 seconds, and poured into a pre-poled hole with a diameter of about 30 W+. After pouring, gas generation stopped approximately 5 minutes after pouring, and cracks appeared in the limestone under all conditions around 60 minutes later. For comparison, similar tests were conducted using commercially available quicklime-based crushing agents of different temperature types. As a result, after 15 hours at 0℃, 18℃ at 20℃
Cracks appeared after 24 hours at 10°C and 2 days at 5°C.

Example 2 Calcium carbide powder 100 parts, amorphous 012 people 7
(Plain value 4500 cm2/l) 10 parts, anhydrous gypsum 10 parts (plain value 5000 cm2/l) Mixture A1 and this mixture A mixed with 10 parts of ordinary Portolan P cement were used. A crushing test similar to 1 was conducted. As a result, no matter which mixture was used, cracks appeared in about 20 minutes and grew to 20 cracks in about 1 hour.

Example 6 To mixture A or mixture B of Example 2, 1% each of soda carbonate and citric acid were added and a limestone crushing test was conducted in the same manner. As a result, in all cases, the film did not harden during the generation of acetylene gas (about 5 minutes), but then rapidly gelled and at the same time began to expand. Gas released from the gelled product was good, and the water reduction effect was also observed, fluidity was ensured with 30% mixed water, and the expansion effect was extremely large.

Example 4 As a water reducing agent for a mixture of 100 parts of calcium carbide powder and 20 parts of ordinary Portland cement, a lignin sulfonate/oxycarboxylate salt was used as a water reducing agent.
"Sunflow" (trade name of Sanyo Kokusaku Pulp Co., Ltd.), β-naphthalene sulfone capped base formalin condensate type I~
1.5q6 of each of "Mighty" (trade name of Kao Soap Co., Ltd.) and "Melment" (trade name of Showa Denko Co., Ltd.) as a water-soluble melamine resin were added, and 60 q6 of water was added.
q6 was added to form a slurry.

Drill 30 holes with a diameter of 38 cm and a length of 1 m in approximately 4 m3 of limestone.
During the main drilling, each of the above slurries was injected into 10 of the holes. As a result, it was crushed into stones with a diameter of about 30 crn in about 30 minutes.

Patent applicant: Denki Kagaku Kogyo Co., Ltd.

Claims (2)

[Claims] (1) A crushing agent for concrete, rocks, etc. containing calcium carbide. (2) A crushing agent for concrete, rocks, etc. containing calcium carbide and hydraulic substances.