JPH0148059B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for statically crushing concrete, etc., using the hydration energy of an expanding agent (hereinafter referred to as an expanding agent) whose main components are hard calcined quicklime and a hydraulic substance, and an expanding tablet used therein. be. A loading hole is drilled into the material to be crushed such as concrete,
A method has been put into practical use in which the loading hole is filled with an expanding agent and the hydration energy of the expanding agent is used to statically crush concrete or the like. However, if a commercially available expanding agent is used for static crushing of concrete, etc., at temperatures exceeding the upper limit of the applicable temperature range of the expanding agent (for example, if the product name is Plaister 200, the applicable range is 5 to 15 degrees Celsius). Yes, but
(when used at temperatures above 15℃), and even when used within the applicable temperature range, the loading hole diameter is 50mmφ
In the above case, the thermal energy of the hydration energy is accumulated inside the expanding agent filled in the loading hole, and this thermal energy converts some of the water in the expanding agent into water vapor, causing water vapor in the loading hole. The pressure increases,
The filling expansion agent explosively protrudes outside the loading hole (hereinafter referred to as protrusion phenomenon), which not only makes it impossible to obtain a crushing effect, but also has the disadvantage that it is extremely dangerous to work with. Furthermore, since the hydration reaction of expanding agents is greatly affected by temperature, it is difficult to widen the applicable temperature range for one type of expanding agent. (For example, if the product is Blister, four types are used depending on the temperature from -5 to 30℃), which makes it difficult to manage production, inventory, and usage, and increases costs. be. In addition, if the product is used at temperatures near the upper limit of the applicable temperature range, it will be used beyond the applicable temperature range when there is a large change in temperature, which often causes the swelling agent to protrude. This has the disadvantage that not only is the crushing effect not achieved, but it is also extremely dangerous to work with. For this reason, as a method to prevent the protrusion phenomenon, after filling the loading hole with an expanding agent, the upper part of the loading hole is tightly plugged with mortar or instruments, as disclosed in Japanese Patent Application Laid-open Nos. 48-25337 and 49-21924. Although methods have been proposed, these methods have the drawbacks of poor workability and high costs. In addition, for example, in Japanese Patent Publication No. 49-43416,
A cylindrical shaped body (the diameter is smaller than the hole diameter and there is a casing pipe insertion hole in the center) made by mixing quicklime with a binder, etc. under pressure is inserted into the loading hole, and water and a hydration reaction retarder are injected. Furthermore, a crushing method has been proposed in which an electric heater is installed inside the casing pipe inserted into the center and electricity is applied to cause a hydration reaction. In this method, by forming a molded body,
Although the workability of filling the expansion agent was improved, work such as installing an electric heater and heating was complicated, and the workability of pouring water was also poor. The present invention aims to improve such drawbacks and provide a method for effectively and safely performing static crushing of concrete, etc. by utilizing the hydration energy of an expanding agent, and an expanding agent used therein. The main components are hard calcined quicklime and hydraulic substances, and an expanding agent containing 30 to 98% CaO component is added by volume.
After filling a loading hole with a three-dimensional expanded tablet formed by compression molding to a size of 0.05 cm ³ to 10 cm ³ and a bulk specific gravity of 2.3 to 3.2, water may be injected. Next, embodiments of the present invention will be described in detail with reference to the drawings. In Fig. 1, reference numeral 1 denotes a material to be crushed such as concrete, into which loading holes 2 of a constant length and diameter are bored at regular intervals, and expanded tablets are inserted into the loading holes 2. 3, water is injected from the opening 4 of the loading hole 2 to hydrate and expand the expandable tablet 3, thereby crushing the object 1 to be crushed. Expandable tablet 3 contains hard calcined lime and hydraulic substances as main components, and CaO content is 30 to 30%.
The raw material is 98% powdered swelling agent. CaO component
If the CaO content is less than 30%, the expansion pressure necessary to crush the object to be crushed cannot be obtained, and if the CaO content is more than 98%, a protrusion phenomenon may occur. Expandable tablet 3 can be obtained by compression-molding a powdered expanding agent as it is in a tablet machine, etc., but in order to particularly improve the moldability, a moistening agent such as a tablet-forming aid (mold release agent) is added. It is desirable to mix the powder with the expanding agent. After compression molding, the size and shape may be adjusted before use. The shape of the expandable tablet 3 is such that water injected from the opening 4 of the loading hole 2 can easily permeate and disperse to the bottom 5 of the loading hole 2, and the filled expandable tablet 3 undergoes a hydration expansion reaction that starts when water is injected. It is preferable that the water vapor gas generated in the expansion tablet 3 can be easily released into the atmosphere through the gaps between the particles of each expansion tablet 3 before the expansion tablet 3 undergoes crystal growth, such as a cylinder, a rectangle, a disk, and a polyhedron. Or, of these, rounded corners and spheres are preferable; in particular, spheres have the smallest surface area, so the space between each particle can be kept small, and the expansion pressure of the expansion tablet 3 can be effectively used, which is most desirable. The expandable tablet 3 is characterized by the ease of loading when filling the loading hole 2, the relationship between the expansion pressure due to the hydration expansion reaction after being filled into the loading hole 2, and the hole diameter of the loading hole 2 (generally 30 to 100 mmφ). In order to obtain the best crushing effect by combining these conditions, the volume of the expanded tablet must be 0.05 to 10 cm ³ . If the particle size is 0.05 cm ³ or less, the protrusion phenomenon tends to occur, and if the particle size is 10 cm ³ or more, the protrusion phenomenon will not occur, but the crushing effect will be reduced and the crushing time will also tend to be delayed. The expanding tablet 3 has a hardness that makes the particles difficult to break when handled, and after filling the loading hole 2, water is injected to start the hydration expansion reaction, and the water vapor generated in the initial reaction is transferred between the particles of the expanding tablet 3. It is necessary that the expandable tablet 3 has a hardness that does not break its shape until it is released into the atmosphere.
Must be between 2.3 and 3.2. If the bulk specific gravity of the expanded tablet 3 is 2.3 or less, the particles may break during handling or the expansion pressure during hydration expansion may be insufficient, and the crushed product 1 will not be completely crushed. If the bulk specific gravity is 3.2 or more, it is not preferable for the production of expanded tablets and for water absorption. According to the method of the present invention, the expanded tablets filled in the material to be crushed release the water vapor generated during hydration and expansion into the atmosphere through the gaps between the expanded tablets, thereby increasing the water vapor inside the expanding agent. Even if the loading hole is 50mmφ or more, or if the expanding agent is used beyond the upper limit of the applicable temperature range,
The filled swelling agent does not protrude outside the hole,
The hydration expansion energy of the swelling agent can be used effectively,
In addition, unlike conventional expanding agents, there is no need to mix the expanding agent and water in a container in advance and immediately fill the loading hole with the mixture; instead, only water can be injected into the expanding tablet filled in the loading hole. Therefore, it is possible to perform crushing work with greater work efficiency and economical effects, and it is also possible to prevent dangers due to protrusion, which has the effect of further increasing work safety.
In addition, during crushing work, because the expanding agent can be used in large holes with a charging hole diameter of 50 mm or more, it is possible to use a larger amount of expanding agent per hole, which increases the crushing force and increases the distance between the holes. Since it is possible to obtain a large number of holes, it is possible to reduce the number of holes required for crushing, which has the effect of making crushing work efficient and economical. In addition, even when used at temperatures outside the applicable range of the expansion agent, there is no reduction in protrusion and a crushing effect is obtained.
Since one type of expanding agent can be used in a wider temperature range, there is no need to use multiple types of expanding agents, and the management of the production, inventory, and use of the expanding agent is efficient and economical. Examples will be explained below. Example 1 Resistance wire length 60 on unreinforced concrete block
The specimen was made with a hole diameter of 60 mmφ, a hole length of 100 cm, and a hole diameter of 60 mm. After filling the loading holes with expanded tablets of Examples 1, 2, and 3 having the shapes and sizes shown in Figure 1 a, b, and c, water was added as an expanding agent (expanding agent components were 60% hard calcined lime, water 20% hard material (40%) was injected by weight, and the protrusion phenomenon of the expanding agent and the crushing condition of the concrete were observed. For comparison, Comparative Examples 1, 2, 3, 4, and 5 in which the size, volume, and bulk specific gravity of the expanding tablets were changed, and a powdered expanding agent were mixed with water in a container in advance (weight ratio 30%). Comparative Example 6, Comparative Examples 7 and 8 were carried out and observed in which a powdered swelling agent or a granular swelling agent was directly filled into the loading hole, and then water was injected at 20% by weight. As a result, it was found that the shape, volume, and bulk specific gravity of the expanded tablet had a large effect on the protrusion phenomenon and percentage.

[Table] *2: Powdered swelling agent is directly filled into the loading hole and then water is injected.
*3: After filling the granular expansion agent directly into the loading hole,
Injected with water.
Example 2 A test specimen was prepared by drilling a resistance wire length of 65 mm, a loading hole diameter of 60 mmφ, and a drilling hole length of 90 cm in unreinforced concrete. After filling the loading hole with the expanded tablet shown in Table 2 (shape: cylindrical, volume 6.0 cm ³ , bulk specific gravity: 2.8), water was injected at 20% by weight of the expanded tablet, and the expanded tablet was hard-burned. The component ratio of quicklime and hydraulic substance, the protrusion phenomenon of expanded tablets, and the crushing condition of concrete were observed (Examples 4, 5, and 6). At the same time, 100% hard-burned quicklime, and the ratio of hard-burnt quicklime to hydraulic substances is
Comparative Examples 9 and 10 using 25/75 expanded tablets were conducted and observed. As a result, it was found that the components of the expanded tablet, hard calcined lime and hydraulic substances, had a great effect on preventing extrusion and crushing concrete.

【table】

【table】 [Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the static crushing method for concrete, etc. according to the present invention, Fig. 2 a, b, c
These are a plan view and a side view of expansible tablets in the form of cylinders, discs, and spheres, respectively, according to Examples. 1... Material to be crushed such as concrete, 2... Loading hole, 3... Expandable tablet, 4... Hole opening of loading hole 2, 5
...Bottom of loading hole 2.

Claims (1)

[Scope of Claims] 1. When statically crushing objects such as concrete using the hydration energy of an expanding agent, the main components are hard calcined quicklime and a hydraulic substance, and the CaO component is
A volume of 0.05 cm ³ to 10 cm ³ of swelling agent containing 30 to 98%,
A method for static crushing of concrete, etc., characterized by filling a loading hole with a three-dimensional expanded tablet formed by compression molding and having a bulk specific gravity of 2.3 to 3.2, and then injecting water. 2 A volume of 0.05 cm ³ to 10 cm ³ of an expanding agent whose main components are hard calcined lime and hydraulic substances and contains 30 to 98% CaO component.
Expandable tablets for static crushing of concrete, etc., which are compression-molded into a three-dimensional shape with a bulk specific gravity of 2.3 to 3.2. 3. For static crushing according to claim 2, wherein the shape of the expandable tablet is a cylinder, a rectangle, a disc, a polyhedron, or one of these with rounded corners, and a sphere. Expanding tablets.