JPH0376982B2 - - Google Patents

Description

[Detailed description of the invention] (1) Industrial application field The present invention relates to a destruction method for destroying objects to be crushed by the expansion pressure generated by kneading an expandable crushing agent and water, and in particular, The present invention relates to a destruction method that allows objects to be crushed to be crushed safely, easily, and in a short time by using a reaction accelerator as a crushing agent.

(2) Background of the technology In general, expandable crushing agents containing calcium oxide (CaO) or magnesium oxide (MgO) as the main ingredients are widely used for demolition and crushing of concrete structures, rocks, and earth. Such expandable crushing agents are filled in the form of a slurry or wet cake mixed with water into holes or grooves made in the object to be crushed, and the material to be crushed is crushed by its hydration expansion. Unlike conventionally used gunpowder and explosives, it does not generate explosive noise, vibration, flying stones, or flying dust, and can significantly improve work stability. In such a crushing method,
The higher the temperature of the slurry or wet cake of the expandable crushing agent is, the more the hydration reaction is accelerated, the rate of development of expansion pressure becomes faster, and the crushing time can be shortened. However, if the hydration reaction of the expandable crushing agent progresses rapidly and the slurry humidity rises rapidly, the water vapor generated by the hydration reaction will cause the slurry or wet cake to spray out all at once from the holes or grooves created in the object to be crushed. There is a risk that a so-called eruption phenomenon (or gun phenomenon) may occur.

(3) Prior art In order to suppress such eruption phenomena and ensure safety, in the past, a method was sometimes adopted in which the hydration reaction of the expandable crushing agent proceeded slowly; There was a problem in that it usually took a long time, as long as one day, to crush the material to be crushed. In addition, as a method for shortening the crushing time, for example, a technique (Japanese Patent Application No. 1983-1983) of heating an expandable crushing agent slurry or a wet cake using a rod-shaped electric heater to protect a casing pipe set in advance in the filling hole is proposed.
29163), and a technique was developed to block the filling hole by using ultra-fast hardening cement or the like at the top of the hole in order to suppress the eruption phenomenon. However, these methods have the problem that the work becomes complicated.

In addition, when heating the opening using the heat generated by hydration of a highly reactive heating agent such as light calcined lime, consideration must be given to the storage of the heating agent, as well as the method of loading the heating agent and the method of water injection. Since the propagation of heat differs depending on the material being crushed, it is necessary to devise a heating agent loading method and a water injection method depending on the temperature of the material to be crushed, the size of the filling hole, etc. The drawback was that it was complicated.

(4) Purpose of the invention The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a crushing method that can crush objects to be crushed safely, easily, and in a short time.

(5) Structure of the Invention In order to achieve the above object, the present invention mixes with water an expansive crushing agent that destroys concrete structures, rocks, etc. by the hydration expansion pressure generated by reaction with water, and creates a slurry. In a destruction method in which a hole made in an object to be crushed is filled in a state or wet cake state and the object to be crushed is crushed by expansion pressure, an expanding crushing agent slurry or a wet cake is filled into a hole made in an object to be crushed. A reaction accelerator for the crushing agent is mixed into the expandable crushing agent slurry or wet cake near the opening of the filling hole, and the reaction of the expandable crushing agent slurry or wet cake near the opening of the filling hole is locally stimulated. It is designed to promote

As the expandable crushing agent, a known expandable crushing agent such as calcium oxide (CaO) or magnesium oxide (MgO) that utilizes hydration expansion is used. Further, as the reaction accelerator, a substance that promotes the reaction can be used depending on the expandable crushing agent used, and calcium chloride is particularly effective and economical. However, it goes without saying that not only calcium chloride but other reaction accelerators can be used as long as they have the same reaction accelerating effect as calcium chloride.

(6) Effect of the invention As described above, the destructive method according to the present invention locally promotes the reaction of the expandable crushing agent slurry or wet cake (hereinafter simply referred to as crushing agent slurry) near the opening of the filling hole. However, since the crushing agent slurry in the part where the reaction is promoted using a reaction accelerator generates reaction heat, the reaction of the crushing agent slurry in the deeper part is promoted by the reaction heat. In addition, the reaction heat generated therein promotes the reaction deeper, and thus the reaction promotion is continuously propagated to the inner part of the filled hole.

On the other hand, the crushing agent slurry causes volume expansion due to hydration reaction, and when this reacts in the filling hole, which is a constraint that limits expansion, as shown in Figure 1, the volume expansion of the crushing agent slurry occurs in the filling hole of the object to be crushed. This results in an expansion pressure 2 (arrow shown in the figure) acting on the wall 1. This expansion pressure 2 becomes a resistance force against push-out stress at the interface between the wall 1 of the filling hole and the hydrated crushing agent, and the hydrated crushing agent acts as a plug to resist the jetting out of the crushing agent from deeper parts. This will fulfill the following objectives.

As mentioned above, the crushing agent slurry in the filling hole is
Due to the reaction heat generated by the reaction promotion near the opening of the filling hole, the reaction continues deeper.
As a result, the pressure of water vapor inside the filling hole increases due to the hydration reaction, but the reacted crushing agent itself continuously forms a thick plug layer that resists ejection.
The water vapor inside the filling hole is sufficiently suppressed and no gushing phenomenon occurs.

(7) Examples Examples of the present invention will be described below.

Example 1 As shown in Figure 2, the object to be crushed is 600 mm on one side.
Using unreinforced concrete specimen 4 formed in mm,
A filling hole 3 with a diameter of 40 mm and a depth of 550 mm was drilled in the center, and a crushing experiment was conducted in a constant temperature room at 20°C. The concrete specimen 4 is one month old and has a compressive strength of 400 kgf/cm ² .

Next, under the above conditions, as shown in Figure 3,
Filling hole 3 is filled with crushing agent slurry 5 (S-Mite A type manufactured by Sumitomo Cement Co., Ltd.) mixed at a water/crushing agent ratio of 27% to a depth of 540 mm, and anhydrous calcium chloride is poured on top of it. A reaction accelerator 6 consisting of granules was filled in an amount of 10 mm so as to reach the opening of the filling hole 3, and the crushing agent slurry and reaction accelerator were further mixed within a depth of 100 mm from the opening of the filling hole 3. . As a result, the temperature of crushing agent slurry 5 was 300℃
60 minutes after filling the crushing agent slurry.
Cracks appeared in the concrete specimen within minutes, and it was able to fracture after 80 minutes.

Example 2 Using the same concrete specimen 4 as in Example 1 above, the crushing agent 5 was an expandable crushing agent S-Mite B type manufactured by Sumitomo Cement Co., Ltd. at a water/crushing agent ratio of 27%.
A crushing experiment was conducted using a powdered product of calcium chloride hexahydrate as the reaction accelerator 6.

First, pour the crushing agent slurry 5 into the filling hole 3 to a depth.
Fill 500mm, then 500mm for crushing agent slurry
A crushing agent slurry that promotes the reaction was prepared by mixing a reaction accelerator consisting of a powder product of calcium chloride hexahydrate in an amount of % by weight, and this crushing agent slurry was filled in an amount of 50 mm. As a result, the temperature of the crushing agent slurry is 250
℃ but there was no eruption after filling the crushing agent slurry.
Cracks appeared in the concrete specimen after 80 minutes, and it was able to fracture after 120 minutes.

In each of the above embodiments, calcium chloride was mainly used as the reaction accelerator, but the present invention is not limited to this, and any material that promotes the hydration reaction of the expandable crushing agent may be used.

Further, in each of the above embodiments, the reaction accelerator 6 is mixed only in the vicinity of the opening of the filling hole 3, but the invention is not limited to this, and as shown in FIG. The reaction promoter 6 may be mixed into the filling hole 3 by gradually decreasing the amount of the reaction promoter 6 from the filling hole 3 to the inner part thereof. In addition, on the contrary, as shown in FIG. 5, a large amount of reaction accelerator 6 is mixed in the deep part of the filling hole 3, and a small amount of reaction accelerator 6 is mixed in the opening side. Good too. In the above case, the former is effective as a means of accelerating the reaction when the object 4 to be crushed is cold and the hydration reaction is delayed, as in the winter, and in the latter case, the filling hole 3 is effective as in the summer.
When the temperature near the opening of the filling hole 3 is high and the deep part of the filling hole 3 is cold, it is effective as a means for accelerating the reaction in the deep part.

(8) Effects As described above, the present invention uses a reaction accelerator to
Since this method causes the hydration reaction of the crushing agent slurry to locally react near the opening of the filling hole drilled in the object to be crushed, hydration occurs from the vicinity of the opening of the filling hole to the deep part of the filling hole one after another. The reaction is propagated. Therefore,
The crushing agent slurry expands due to hydration reaction,
Since a thick plug layer is continuously formed to resist blowouts, blowouts do not occur even when the pressure of water vapor in the crushing agent slurry increases, making it possible to crush objects to be crushed in an extremely safe manner. can.

In addition, the crushing agent slurry itself, which expands due to the hydration reaction, becomes a plug that resists ejection, so there is no need to use rapid hardening cement to block the filling hole as in the past, simplifying the work. .

In addition, when the reaction is promoted at the opening of the filling hole,
The heat of reaction promotes the hydration reaction of the crushing agent slurry in the deep part, so there is no need to heat it using a heating device or heating agent as in the past, and the crushing agent can be crushed in a short time. This has the effect of eliminating the trouble of preparing a heating means in advance.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the expansion pressure of an expansible crushing agent acting on the wall surface of a filling hole opened in an object to be crushed, and Fig. 2 shows a concrete specimen used in an example according to the present invention. 3 is a sectional view showing a state in which a mixture of an expandable crushing agent and water is filled in a hole drilled in an object to be crushed, and FIGS. 4 and 5 are
The figure is a sectional view showing another embodiment according to the present invention. 3...Filling hole, 4...Object to be crushed (concrete specimen), 5...Expansible crushing agent slurry, 6...
Reaction accelerator.

Claims (1)

[Claims] 1. An expansive crushing agent that destroys concrete structures, rocks, etc. due to hydration expansion pressure generated by reaction with water is mixed with water and applied to the object to be crushed in a slurry state or a wet cake state. In this method, an expandable crushing agent slurry or a wet cake is filled into a filling hole drilled in a material to be crushed, and the area near the opening of the filling hole is A reaction accelerator characterized in that a reaction accelerator for the crushing agent is mixed into the expandable crushing agent slurry or the wet cake to locally promote the reaction of the expandable crushing agent slurry or the wet cake near the opening of the filling hole. The destructive method used. 2. The destructive construction method using a reaction accelerator according to claim 1, wherein the reaction accelerator is calcium chloride.