JPH0146678B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for cutting and destroying solid and brittle objects such as concrete structures and rocks.

[Prior Art] Recently, construction methods have been widely used to destroy solid and brittle objects such as concrete structures and rocks by applying the volumetric expansion properties of quicklime and the like upon hydration. Compared to conventional dynamite construction methods, this construction method is noiseless, vibration-free, blast-free, and poses no risk of pollution, so it is widely used, especially in urban areas, expressways, and airport expansion construction. ing.

When destroying concrete, rocks, etc. using the hydration expansion pressure of an expandable crushing agent such as quicklime, follow a design that takes into consideration the size, shape, and size of the object to be destroyed in advance. Then, an appropriate number of holes are made in the object to be destroyed, and a slurry prepared by mixing an expansive crushing agent (quicklime), an alkali or other reaction retardant, and water is injected and filled into the holes. The filled expandable crushing agent slurry causes a hydration reaction in the hole and expands, and the pressure of the expansion destroys concrete, rocks, etc.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional method, (1) The drilling work to create a designed filling hole in concrete, rock, etc. is performed using an electric drill, crawler drill, etc. along the expected break line. In order to obtain the fracture directionality, that is, to fracture along the expected fracture line, holes are normally drilled at intervals of 10 to 15 times the hole diameter, and the amount of work involved is extremely large. big.

(2) The total time required for the series of operations of drilling a hole in the object to be destroyed and filling it with a mixed slurry of an expandable crushing agent and a reaction retarder, and the subsequent destruction, usually takes a long time, from 12:00 to 24 hours. The structure of the object to be destroyed,
Depending on the condition of the reinforcing bars, rock quality, etc., the crack initiation time may be delayed further.

(3) When the object to be destroyed becomes hot (when heat cannot escape easily), the expanding crushing agent in the form of slurry causes abnormal expansion (so-called gun phenomenon) due to heat generation during the hydration process, which is dangerous. There were various problems such as...

Therefore, the present invention solves various problems of the conventional method of drilling a hole in the object to be destroyed and filling it with a mixed slurry of an expandable crushing agent and a reaction retarder, and the work is simple, quick, and safe. It is an object of the present invention to provide a method for destroying brittle objects such as concrete and rocks that is highly economical and can shorten the time required to destroy the object to be destroyed.

[Means for Solving the Problems] In the method for destroying brittle objects such as concrete and rocks according to the present invention, a groove is created along the expected fracture line of the brittle object such as concrete and rock, and quicklime, etc. is placed in the groove. An expandable crushing agent is press-fitted into the container, the material is hydrated and expanded, and the object to be destroyed is destroyed by the expansion pressure.

A method for destroying a brittle object such as concrete or rock according to another aspect of the present invention includes making at least one or more perforations along a predicted fracture line of the brittle object such as concrete or rock, and forming a groove connecting the perforations. Injecting and filling a slurry-like expandable crushing agent to which a reaction retardant has been added into the perforation, injecting and filling an expandable crushing agent such as quicklime into the groove and causing it to hydrate and expand; The object to be destroyed is destroyed by the expansion pressure of the expandable crushing agent.

[Function] The method of the present invention applies one or more pieces to a brittle object such as concrete or rock along an expected fracture line, taking into account the size, shape, size after destruction, etc. of the object to be destroyed. After making a groove and press-filling the powder of an expandable crushing agent such as quicklime into the groove, it is hydrated and expanded.
It is characterized by destroying the object to be destroyed by its expansion pressure, and in another invention, it is combined with conventional perforation and an expansion agent in the form of a slurry containing a mixture of an expansion crushing agent and a reaction retarder. This method uses a combination of the method of filling a crushing agent. This will be explained in detail below.

In the method of the present invention, instead of conventional drilling, concrete,
Create a narrow, shallow trench along the expected fracture line of the rock or other object to be destroyed. The width of the groove is about 1 to 5 mm, and the depth is usually about 10 to 150 mm. This groove cutting work can be performed relatively easily with a diamond cutter or the like, and a commercially available electric diamond cutter can be used for this purpose.

The number of the grooves is one or more as necessary,
The spacing, position, direction, etc. of these may be changed as appropriate depending on the condition of the object to be destroyed. Further, the depth of the groove can be adjusted by controlling the diamond cutter portion, but it is preferable that it be as deep as possible. Furthermore, if there are natural cracks in the rock, etc., the natural cracks may be used as an expected fracture line and a groove may be formed along the line.

Expandable crushing agents to be filled in the grooves include quicklime, light calcined dolomite, hard calcined quicklime, dead calcined dolomite, silicates containing free lime, and other crushing agents that expand in volume through hydration reactions. , it can be used as it is in powder form without adding a reaction retarder or the like.

In other words, in the conventional wet filling method using slurry, it was necessary to use a reaction retarder to prevent expansion during construction, which caused damage.
A long period of time, approximately 12 to 24 hours, was required. The present invention has a major feature in that a dry method without adding a reaction retarder can be used.

Therefore, the addition of alkalis, water glass, fluoride, lignin, sodium gluconate, and other inorganic and organic reaction retarders, which are added to suppress the hydration expansion rate of conventional quicklime systems, is not particularly necessary. In the present application, it is of course also possible to use expandable disintegration agents with added reaction retarders in the process of the invention.

In order to fill the expandable crushing agent powder into the grooves provided in the object to be destroyed as described above, use a suitable thin iron plate, etc., to thoroughly cover the expandable crushing agent placed in the grooves. Fix it. Various methods are possible for filling the powder, such as using the powder as it is or using the powder packed in an elongated paper bag or the like. The inside of the groove may be moistened with water before filling. However,
After filling the expandable crushing agent up to the top surface of the groove, the surface is hydrated by spraying water or the like. Warm water can also be used for hydration if necessary.

Another method of the present invention uses a combination of grooves and an expandable crushing agent, as well as injecting a slurry of expandable crushing agent with a conventional reaction retardant into the perforated area. That is, the fracture caused by the expansion of the perforated portion provided along the expected fracture line is added to the fracture caused by the expansion of the groove portion connecting the perforations along the expected fracture line, increasing the directionality of the fracture direction. This eliminates the need for shortening the interval between holes in order to obtain directionality in the crushing direction when only holes are used, and the number of holes can be reduced.

[Example] Next, examples of the present invention will be described.

Experimental Example 1 Test Piece (1) A destructive test was conducted using a cylindrical concrete test piece with a diameter of 15 cm and a height of 30 cm. Ordinary Portland cement is used for the concrete mix, and the mixture is: Ordinary Portland cement: Sand:
Gravel = 1:2:4, and the amount of water was 45% of the amount of cement. This concrete test piece was cured in water for more than 4 weeks, and its compressive strength was 325 kg/cm ² after 4 weeks.

Comparative Example 1-1 The above test piece has a diameter at the center of the cylinder and on the axis.
A circular hole of 35 mm and 200 mm in depth was made and filled with a slurry of a commercially available quicklime-based expanding crushing agent (trade name: Splitter, manufactured by Yoshizawa Lime Industry Co., Ltd.) (water volume was 30% of the expanding crushing agent). However, it took 15 minutes before the crack appeared.
It took time.

Comparative Example 1-2 A test piece similar to Comparative Example 1-1 above was made with a groove parallel to the axis of 2.5 mm in width and 20 mm in maximum depth on the outer periphery of a cylinder similar to that shown in Fig. 1 using a diamond cutter. When a slurry of quicklime-based expansive crushing agent (product name: Splitzer, manufactured by Yoshizawa Lime Industry Co., Ltd.) (water volume is 30% of the expanding crushing agent) was filled into the groove on the outer periphery of a shaped test piece, cracks appeared. 72～
It took 96 hours.

Example 1 A test piece similar to those in Comparative Examples 1-1 and 1-2 above had a width of 2.5 mm and a maximum depth of 20 mm on the outer periphery parallel to the axis.
One groove was created using a diamond cutter. Figure 1 shows a cylindrical test piece with a groove cut on its outer periphery; in the figure, 1 indicates the concrete test piece and 2 indicates the groove. Quicklime-based expandable crushing agent powder to which no reaction retardant was added was press-fitted into the groove, and after filling the entire groove, water was sprinkled on the surface. A crack appeared on the test piece 120 minutes after watering, and the test piece was divided into two by tapping the crack with a hammer. According to the method of the present invention, the time until destruction was shortened by 1/7 or less compared to the conventional method of Comparative Example 1-1.

Experimental Example 2 Test Piece (2) A fracture test was conducted using limestone with a size of approximately 1.5m x 1.5m x 1.0m. Note that FIG. 2a shows a large number of perforations according to the conventional method, and FIG. 2b shows a combination of grooves and a small number of perforations according to the method of the present invention. In the figure, 3 is limestone, 2 is a groove, and 4 is a perforation. As shown in the figure, the number of perforations is smaller in the method of the present invention than in the conventional method.

Comparative Example 2 As shown in Fig. 2a, five holes with a hole diameter of 40 mm and a hole length of 80 mm were drilled in the test piece of limestone 3, and a commercially available quicklime-based expander to which a reaction retardant had been added was used. When a 30% slurry of a crushing agent (trade name: Splitter, manufactured by Yoshizawa Lime Industry Co., Ltd.) was filled, cracks appeared in 19 hours.

Example 2 As shown in Figure 2b, three holes with a hole diameter of 40 mm and a hole length of 80 mm were drilled in the test piece of limestone 3, and a diamond cutter was used between the holes to drill holes with a width of 5 mm and a depth of 30 mm. Although the grooves 2 were cut and connected, the perforated portion 4 was filled with a 30% slurry of a commercially available quicklime-based expanding crushing agent (trade name: Splitter, manufactured by Yoshizawa Lime Industry Co., Ltd.) to which a reaction retardant was added. Then, an expandable crushing agent powder to which no reaction retardant was added was press-fitted into the groove. When this groove was covered with a cloth moistened with water, cracks appeared in 9 hours, indicating that the method of the other invention was highly effective.

[Effects of the Invention] As explained above, the present invention has the following effects by using the method of the present invention.

(1) Creating grooves with a width of 1 to 5 mm in the object to be destroyed using a diamond cutter or the like is extremely easy compared to conventional drilling work, and can significantly shorten the working time.

(2) Expanding crushing agents such as quicklime that are filled into the grooves of the object to be destroyed are very shallow (approximately 10 to 150 mm) in depth, and the filling density can be increased, so that they are generated during the hydration process. It is safe because heat is sufficiently dissipated and there is no abnormal expansion phenomenon.

(3) There is no need to specially mix a reaction retarder with the expandable crushing agent.

(4) The time required for cracks to appear in the object to be destroyed is greatly shortened.

Further, according to another invention of the present application, in addition to the above-mentioned effects, there are effects such as being able to reduce the number of perforations provided along the expected fracture line and making the fracture direction more directional.

[Brief explanation of drawings]

Figure 1 is a diagram showing a cylindrical concrete test piece with grooves cut by the method of the present invention;
is a perspective view, and b is a plan view. FIG. 2a is a plan view showing a state in which limestone is perforated, and FIG. 2b is a plan view showing a state in which perforations and grooves are provided. 1: Concrete test piece, 2: Groove, 3:
Limestone, 4: perforation.

Claims (1)

[Scope of Claims] 1. A groove is created along the expected fracture line of a brittle object such as concrete or rock, and an expandable crushing agent such as quicklime is press-filled into the groove and expanded by hydration. Concrete characterized by destroying objects to be destroyed by expansion pressure,
A method of destroying brittle objects such as rocks. 2 The expandable crushing agent press-fitted into the groove is
2. The method for breaking brittle objects such as concrete and rocks according to claim 1, wherein the crushing agent is a powdered expandable crushing agent that does not contain a reaction retarder. 3. Create at least one or more perforations along the expected fracture line of a brittle object such as concrete or rock, create a groove connecting the perforations, and create a slurry-like expansive crusher with a reaction retardant added in the perforations. The method is characterized by injecting and filling an expandable crushing agent such as quicklime into the groove, causing it to hydrate and expand, and destroying the object to be destroyed by the expansion pressure of the two expandable crushing agents. concrete,
A method of destroying brittle objects such as rocks. 4. The expandable crushing agent press-fitted into the groove is
4. The method for breaking brittle objects such as concrete and rocks according to claim 3, wherein the crushing agent is a powdered expandable crushing agent that does not contain a reaction retarder.