JPS61250265A - Limited static crushing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a limited static crushing method using a hydrated expandable material. [Conventional technology] As a method for safely crushing concrete and rocks without making noise or taking pictures, holes or grooves are provided in the object to be crushed, and a hydration-expandable substance is filled in the holes or grooves, which are then used to crush concrete or rocks using expansion force. A static crushing method is known in which the material waits for crushing. As the hydration expansion progresses, if the expansion pressure exceeds the strength of the object to be crushed, cracks will occur, leading to fracture. Conventionally, it has been nearly impossible to control the direction of these cracks, and cracks usually occur radially from the bottom of the hole or groove, that is, not only laterally, but also inward. Ta. This is not a problem when attempting to destroy the entire structure, but is inconvenient when attempting to destroy only a limited portion of the structure. Limited destruction is required, for example, when a concrete floor contaminated with oil or radiation is to be removed by a certain thickness in order to renew the floor. However, with conventional static crushing technology, the impact of crushing extends to the interior, so there is a risk of weakening the floor, and if this is unacceptable, the entire floor must be replaced. There wasn't. Needless to say, this is uneconomical, so there has been a demand for the development of a limited static crushing technique that can limit the effects of static crushing to desired areas. [Problems to be Solved by the Invention] An object of the present invention is to provide a limited static crushing method that meets the above requirements. R Rijisho feeling

[Means to solve the problem]

The limited static crushing method of the present invention is a method in which grooves or holes are provided in the object to be crushed, such as rocks or concrete, and crushing is performed using the expansion pressure of a hydration-expandable material filled in the grooves or holes. It is characterized by inserting a pressure-absorbing material into the bottom of the groove or hole and filling it with a hydrated expandable material. As the material for absorbing the expansion pressure of the hydrated expandable substance, a material selected from rubber, plastic, wood chips, sand, gravel, paper, etc. alone or in combination thereof is used. As a typical example, when attempting to perform limited crushing to remove a certain thickness of a concrete floor, as shown in FIGS. As shown in Figure 2,
At the bottom of every other groove 21 is a material 3 that absorbs the inflation pressure.
is inserted, and the hydrated expandable material 4 is filled thereon. As the hydration expansion progresses, cracks occur on both sides of the groove 21, as shown in FIG. The portion separated by this crack can be easily removed, and as shown in FIG. 4, limited crushing is performed in which only the surface is removed. In addition, in order to perform limited crushing of the shaft head portion of a concrete pit, as shown in FIGS. Insert a material 3 absorbing the inflation pressure into the bottom of the container and fill it with hydrated intumescent material.

[For use]

By inserting a material 4 that absorbs the expansion pressure of the hydrated expandable material at the bottom of the groove or hole, the expansion pressure toward the bottom is absorbed and the expansion pressure acts only in the lateral direction. If this pressure exceeds the strength of the object to be crushed, cracks will occur that run in the lateral direction. As illustrated by Hatondo, the point at which cracks occur is near the boundary between the hydrated expandable material and the expanded pressure absorbing material, which is natural considering that stress is concentrated in that area. It will be understood as In this way, the concrete can be crushed to a desired depth without causing cracks in the lower concrete that is to be preserved, achieving limited static crushing.

[Example 1] Using 1/3 unreinforced concrete plates with a width of 2TrL, a length of 15m, and a thickness of 15mm, use a diamond cutter to cut grooves with a width of about 5m and a depth of 5cm at a pitch of 5ctrts7°5. It was formed with three types of pitch: cm and 10 cm. Place two 5m thick black rubber sheets cut to match the width of the grooves at the bottom of every other groove, and add approximately 80% CaO.
A hydrated swellable material based on %% was mixed with water and filled. The results were as follows. (1) In the 5 cm pitch portion, cracks continued from groove to groove after 6 hours, and the concrete surface layers 4 to 5α were completely separated. (2) The portion with a pitch of 7.5 cm also became the same as above after 6.5 hours. (3) Cracks formed in the 10 cm pitch area after 7.5 hours, and although some of the cracks did not reach the adjacent grooves, it was possible to separate 4 to 5 cm of the surface layer with a light blow. From this result, it can be said that the interval between the grooves should be within twice the depth. [Example 2] Reinforcing bars were placed in a hole dug out of earth and sand, and concrete was poured into the hole to create a cast-in-place pit with a diameter of 1500 InIr1. At that time, a PVC tube was placed over the top 1TrL of the reinforcing bars to prevent concrete from adhering to it, and a PVC tube with a length of 10cm was placed on the bottom of a PVC pipe with an outer diameter of 50m and a length of 1TrL.
The pipes were filled with rubber rods of 1.5 cm in diameter and plugged, and placed in such a way that the distance between each pipe was 5 to 10 times the outer diameter.
After concrete assimilation, the pipe was filled with a CaO-based hydrated expandable material mixed with water. Only the 90 to 100 cm head portion could be easily removed without affecting the main body of the mine. By using the method of the present invention, limited parts such as the surface layer and edges of rocks and concrete can be statically crushed and removed, and the remaining parts remain as they are without undergoing any deterioration. It can be used effectively. It is suitable for removing part of the surface of a concrete floor to install machine tools, large computers, etc., removing areas contaminated with oil or radiation, and is also useful for breaking down the head of a foundation pile. Melt.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing grooves provided in the object to be crushed, with A being a plan view and B being a sectional view. Figures 2 to 4 are cross-sectional views illustrating the principle of realizing limited static crushing, and Figure 2 shows the insertion of a material that absorbs expansion pressure into the bottom of every other groove in the object to be crushed. Fig. 3 shows the cracks formed on both sides of the groove of the object to be crushed, and Fig. 4 shows the case where a hydrated expandable material was filled on top of the crushed object. This shows where the concrete has been removed. FIGS. 5 and 6 are diagrams illustrating the case where the present invention is applied to the shaft head portion of a basic concrete mine, with FIG. 5 being a plan view and FIG. 6 being a longitudinal sectional view. 1A, 1B...Body to be crushed 2...Groove 3...Material that absorbs expansion pressure 4...Hydration expandable material 5...Crack 6...Reinforcing bar 7...PVC pipe patent Applicant Yoshizawa Lime Industry Co., Ltd. Agent Patent Attorney Souo Suga Figure 1 Figure 2 Figure 31! l No.41!1

Claims (4)

[Claims] (1) In a method in which grooves or holes are provided in the object to be crushed, such as rocks or concrete, and the expansion pressure of a hydration-expandable substance filled in the grooves is used for crushing, the material that absorbs the expansion pressure is placed in the grooves. Or a limited static crushing method characterized by inserting it into the bottom of the hole and filling it with a hydrated expandable material. (2) The method according to claim 1, wherein a plurality of grooves are provided and every other groove is filled with a hydration-swellable substance. (3) The method according to claim 1, which is carried out by forming a hole by fixing a bottomed pipe prior to pouring concrete, and filling the hole with a hydration-expandable substance. (4) The method according to claim 1, wherein the material absorbing the expansion pressure is selected from rubber, plastic, wood chips, sand, gravel, paper, etc.