JPH0249787B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for underwater crushing of brittle objects such as rocks and concrete using a static crushing agent. Various methods of crushing brittle objects have been proposed in the past, and a practical method includes, for example, a method using a static crushing agent. This is a method in which a slurry of an expandable substance whose main component is quicklime is injected into holes made in a brittle object, and the expansion pressure is utilized (see Japanese Patent Laid-Open No. 56-67059). However, while this method poses no problem when crushing brittle objects on land, when it is under water,
Even if slurry is injected into the hole using a pump, etc.
There was a practical problem that it was diluted with water and the expansion pressure was reduced, making it impossible to crush. The present invention solves this problem and proposes a method for crushing brittle objects located below the water surface. That is, the present invention provides a container made of a flexible or easily breakable material that can transmit the expansion pressure generated inside the perforation of a brittle object under water to the outside through the container wall. It is characterized in that after the opening is inserted so that it is above the water level, the opening is filled with a substance that expands by hydration. Hereinafter, the present invention will be explained based on the drawings. The drawings are schematic cross-sectional views for explaining the present invention. The reference numeral 1 indicates that the object is a brittle object, and a perforation 2 is provided near the center thereof.
The container 3 is inserted into this perforation with its opening projecting above the water surface. The material of the container is a flexible or easily breakable material that transmits the expansion pressure generated inside the container to the outside through its walls, and specific examples thereof include polyethylene, polypropylene, polyester, polyvinyl chloride, and polyvinyl. These include synthetic resins such as alcohol, cloth, Japanese paper, rubber, and glass. Its shape is comparable to that of a perforation, and although a bag-like body is usually used, it is not limited to this. However, a container as described below is desirable. In other words, it is preferable that the thickness of the container wall be within 1 mm.Thickness significantly exceeding 1 mm will act as cushioning material and absorb expansion pressure, and container walls that are extremely thin will not break when inserted into the hole. This is not desirable as there is a risk of Therefore, a thickness of about 0.1 to 0.5 mm is usually used, and the effect will not change even if the thickness exceeds 0.5 mm as long as the thickness is about the same as the diameter of the perforation. If the diameter of the container is significantly larger than the diameter of the perforation, the perforation will overlap and create a void, making it impossible to transmit large expansion pressure, and if the diameter of the container is smaller than that, a void will be created between the container and the hole wall. gives similar results. Therefore, it is most preferable for the container diameter to be about the same as the diameter of the perforation, but containers that are about 2 mm smaller than the perforation diameter to larger than the perforation diameter are used, even if they overlap within the perforation, up to about twice. When inserting the container into the borehole, the container can be easily inserted into the borehole by inserting the support 4, such as a rod or tube, into the container in advance. If the container is crushed by water pressure, which interferes with the filling of the expandable substance, use a tube as a support, fill the expandable substance through the tube, and then gradually pull it out. This is the preferred method because it allows for smooth filling and good adhesion between the container and the hole wall. The expandable material filled in the container is mixed with water to form a fluid slurry. Filling can be carried out by pump pressure feeding or by gravity flow using a funnel or the like. Examples of expansive substances include those that are mainly composed of quicklime, those that are mainly composed of calcium arbide, those that are mainly composed of magnesia, calcium saphoaluminate-based substances, and those that exhibit hydration expansion such as dolomite. The above are used. Among these, it is now possible to use those with a high reaction rate that could not be used in the past, and this makes it possible to crush them in an extremely short time. Furthermore, more effective crushing can be achieved by adding a hydraulic substance, a water reducing agent, a setting retarder, a reaction rate regulator, etc. to these expandable substances. As the hydraulic substance, Portland cement, slag, alumina cement, a mixture of calcium aluminate and gypsum, hydraulic calcium aluminate, fast-setting cement, hemihydrate gypsum, etc. can be used. Among these, combinations in which the reaction rate of the expandable substance and the curing rate of the hydraulic substance are as similar as possible and as fast as possible are preferable. For example, a combination of a fast-reacting expansive material such as quicklime, magnesia or calcium chibide with a low firing temperature and a fast-setting cement or hydraulic calcium aluminate is most preferred. Examples of water reducing agents include lignin type, higher polyhydric alcohol sulfonate type, alkylaryl sulfonate and its high condensate type, polyoxyethylene alkyl ether type, oxyorganic acid type, polyol composite type, and water-soluble melamine resin. One or a mixture of two or more of the following are used: Examples of setting retarders include water-soluble organic carboxylic acids or salts thereof such as gluconic acid, tartaric acid, citric acid, and malic acid, sodium carbonate, sodium hydrogen carbonate, potassium carbonate,
One or more selected from alkali carbonates such as potassium hydrogen carbonate can be used, and it is particularly preferable to use a water-soluble organic carboxylic acid or a salt thereof in combination with an alkali carbonate. As the reaction rate regulator, water-soluble alkali salts such as caustic soda and caustic potash, or silica fluorides are preferred.
In addition, the amount of these expandable materials used is usually 700 tons/
The amount may be such that an expansion pressure of m ² or more can be obtained. As explained above, the present invention provides underwater crushing of a brittle object in which an opening of a container is inserted into a hole in a brittle object under the water surface with the opening protruding above the water surface, and an expandable substance is filled from the opening. method, whereby the expandable material is not diluted in water;
In addition, since the hole is evenly filled from the bottom, the same crushing effect as onshore construction can be achieved. Hereinafter, the present invention will be explained in more detail with reference to examples. Example 1 Hydraulic material consisting of an equal weight mixture of amorphous calcium aluminate and type anhydrite having a Blaine specific surface area of 3200 cm ² /g, 60% by weight of quicklime, 10% by weight of silica sand and a composition of 12CaO.7 Al ₂ O ₃ For every 100 parts by weight of the substance at a ratio of 30% by weight, 2 parts by weight of a commercially available water reducer (trade name ``Ultrazine'') whose main component is calcium lignin sulfonate and a set retarder (70% by weight of potassium carbonate, glucone). 10 parts by weight of a mixture of 13% by weight of sodium acid and 17% by weight of citric acid was used as a crushing agent, and 100 parts by weight of this mixture was mixed with 35 parts by weight of water to prepare a slurry. The expansion pressure of each container material and shape by this slurry was measured by the following method. i.e. inner diameter 36
A steel plate is welded to the bottom of a carbon steel pipe with a length of 600 mm, and a gauge length of 10 mm is placed at the center of the height of the steel pipe surface.
After filling a steel pipe with water and inserting a paper strain gauge (mm) in the circumferential and axial directions, the container was inserted. When inserting the container, a hard PVC tube with an outer diameter of 32 mm is used as a support, and the tube is filled with slurry while being gradually pulled out.The expansion pressure is calculated from the distortion of the steel tube. did. The temperature was measured at 20℃. Table 1 shows the results by container material, and Table 2 shows the results by wall thickness when the container is made of polyvinyl chloride.
The results for each diameter are shown in Table 3.

【table】

【table】

[Comparative example 1]

The same cylindrical mortar specimen as in Example 2 was crushed using a powdered expandable substance. A polyethylene container with a diameter of 50 mm and a wall thickness of 0.2 mm was inserted into the perforation of the specimen together with a support made of a polyvinyl chloride tube with an outer diameter of 28 mm. Next, a glass water supply pipe with a diameter of 8 mm was inserted into the hole in the support so that it was located deep inside the polyethylene container, and the support was gradually pulled out while being filled with the powder of the expandable substance of Example 1. Then, a drainage pipe was set at the top of the powder, and the opening of the container was closed. Next, when water was supplied from the water supply pipe,
It took three hours for water to overflow from the drainage pipe. As a result, approximately 40 hours after the start of water supply, the specimen was broken into four pieces.

[Brief explanation of the drawing]

The drawings are schematic cross-sectional views for explaining the present invention, in which reference numeral 1 indicates a brittle object, 2 indicates a perforation thereof, 3 indicates a container, and 4
is the support.

Claims (1)

[Claims] 1. A container made of a flexible or easily broken material that transmits the expansion pressure generated inside to the outside through the container wall is placed in a perforation of a brittle object below the water surface, and the opening of the container is above the water surface. A method for underwater crushing of a brittle object, which comprises inserting the object in the upper position and then filling the opening with a slurry of an expandable substance due to hydration.