JPH01247663A - How to dismantle concrete structures - 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] [Industrial Application Field] The present invention relates to a method for dismantling concrete structures, and in particular, a method for dismantling concrete structures using an inorganic salt compound in a solution state that has the property of freezing at a high temperature higher than natural atmospheric temperature. This invention relates to a method for dismantling a concrete structure in which the concrete structure is hermetically sealed and then cracked and destroyed by freely manipulating the two-phase changes of freezing, melting, and freezing.

[Conventional technology]

Conventionally, methods for dismantling this type of concrete structure include the blasting method, in which the concrete structure is blasted and demolished using dynamite, and the mechanical impact method, in which mechanical impact force is applied to the concrete structure using a hammer, etc. widely known.

[Problem that the invention seeks to solve]

However, all of the conventional demolition methods mentioned above generate significant noise and vibration during demolition, and their use is limited in terms of preventing damage to adjacent buildings and surrounding residents. There was a drawback.

The object of the present invention has been made in view of the above-mentioned drawbacks.
To provide a method for dismantling a concrete structure that reduces noise and vibration during dismantling and facilitates dismantling work.

[Means for solving problems]

In order to achieve the above object, the method for dismantling a concrete structure according to the present invention includes the steps of: drilling a hole downward to a depth that reaches the center of the thickness of the concrete structure;
An electric heating coil that can be energized from the outside is installed at the tip of the drilled hole, and while heating and maintaining the temperature of the tip at a predetermined temperature, the freezing point is set below the holding temperature and above the natural atmospheric temperature. After injecting a first inorganic salt compound solution having a By generating a frozen layer of a second inorganic salt compound solution with a desired thickness above the inorganic salt compound solution, and then filling the reinforced cement into the excavated hole up to the frozen layer without any gaps and solidifying it. The first inorganic salt compound solution is sealed in the concrete structure, the electric heating coil is de-energized, and the concrete structure is caused to crack and break due to the internal pressure increasing action when the first inorganic salt compound solution freezes. It is designed to occur.

[Effect]

In the present invention, after the first inorganic salt compound is sealed in a concrete structure, when electricity is cut off to the electric heating coil, the temperature of the first inorganic salt compound solution decreases due to natural heat radiation, and the first inorganic salt compound solution freezes. . The internal pressure increases due to volumetric expansion at this time, causing cracking and failure of the concrete structure. Therefore, in the method of the present invention, noise during demolition,
The generation of vibration can be suppressed to the lowest possible level.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

Figure 1 is a plan view showing an example of a concrete structure, Figure 2 is a plan view showing an example of a concrete structure.
The figure is a side sectional view thereof, and FIG. 3 is an explanatory diagram of the method for dismantling a concrete structure according to the present invention.

The concrete structure 1 has a drilled hole 2 deep enough to reach from the upper end to the center thereof, and an electric heating coil 3 is disposed at the tip of the drilled hole 2. An electric wire 4 that can be turned on and off from the outside is connected to the electric heating coil 3 (see FIG. 3).

A first inorganic salt compound solution 5 is injected into the excavated hole 2 to a position where the electric heating coil 3 is buried. That is, the first inorganic salt compound solution 5 is injected and dissolved while being heated by the electric heating coil 3, and at the same time, the first inorganic salt compound solution 5 is formed into a bag-shaped bag with an open top at the upper end of the first inorganic salt compound solution 5. A bent vinyl sheet 6 is provided. A second inorganic salt compound solution 7 is contained in the vinyl sheet 6.
is injected and frozen. Therefore, a frozen layer (second inorganic salt compound 7) having an arbitrary thickness is formed above the first inorganic salt compound solution 5.

The freezing point temperature T1 of the first inorganic salt compound solution 7 and the freezing point temperature T2 of the second inorganic salt compound solution 7 are set as follows.

T+' (t a + t+), where t
a is the natural atmospheric temperature, T2'i (t a+ t, +
t2) respectively.

Further, on the frozen layer made of the second inorganic salt compound solution 7,
Reinforced cement 8 is filled in the excavated hole 2 without any gaps, and as the reinforced cement 8 solidifies, the first inorganic salt compound solution 5 is sealed in the concrete structure 1 in a liquid state.

After setting in this manner, when dismantling the concrete structure 1, first the electricity to the electric heating coil 3 is cut off. Then,
Due to natural heat radiation, the temperature of the liquid first inorganic salt compound solution 5 decreases to its freezing point, and it freezes while exhibiting a volumetric expansion phenomenon. For this reason, the internal pressure of the concrete structure 1 increases extremely, which causes the concrete structure 1 to
causing cracking and destruction.

Table 1 below shows the inorganic salt compound solutions used and their freezing points (°C).

Table 1 [Effects of the Invention] As explained above, according to the method for dismantling a concrete structure according to the present invention, two types of inorganic salt compound solutions with different freezing points are used, and a A frozen layer of the other inorganic salt compound solution is generated, and reinforcing cement is filled onto the frozen layer and solidified to seal the one inorganic salt compound solution within the concrete structure.

After this, when the power to the heating coil is cut off, the temperature of one inorganic salt compound solution decreases due to natural heat radiation, and it freezes. can generate ultra-high pressure due to
This allows even relatively large concrete structures to undergo cracking and failure due to increased internal pressure. Therefore, according to the present invention, it is possible to easily carry out subdivision work that is easy to transport and move, and when destroying a concrete structure, it does not cause damage to other nearby structures such as scattering of fragments or generate loud noise. It has the excellent effect of being able to perform static disassembly without causing damage. In addition, since the destruction of concrete structures utilizes the expansion pressure when the inorganic salt compound solution freezes, it has a large energy saving effect.

[Brief explanation of the drawing]

Figure 1 is a plan view showing an example of a concrete structure, Figure 2 is a plan view showing an example of a concrete structure.
is a side sectional view thereof, and FIG. 3 is an explanatory diagram of the method for dismantling a concrete structure according to the present invention. 1... Concrete structure, 2... Drilling, 3
... Electric heating coil, 4... Electric wire, 5... First inorganic salt compound solution, 7... Second inorganic salt compound solution, 8... Reinforced cement. Applicant: Hitachi Plant Construction Co., Ltd.

Claims (1)

[Claims] A drilling hole with a depth that reaches the center of the thickness of the concrete structure is provided downward, and at the tip of the drilling hole,
A first inorganic salt compound that is provided with an electric heating coil that can be freely energized from the outside, and that while heating and maintaining the temperature of the tip at a predetermined temperature, has a freezing point naturally in a range that is below the holding temperature and above atmospheric temperature. After injecting the solution into the excavated hole until the electric heating coil is buried, a second inorganic salt compound solution having a freezing point higher than the holding temperature is introduced, and a second inorganic salt compound solution is poured above the first inorganic salt compound solution. The first inorganic salt compound solution is formed by forming a frozen layer of an arbitrary thickness of the inorganic salt compound solution of No. 2, and then filling the reinforced cement into the excavated hole without any gaps up to the frozen layer and solidifying it. is sealed in a concrete structure, the electric heating coil is de-energized, and the concrete structure is caused to crack and break due to the internal pressure increasing effect when the first inorganic salt compound solution freezes. method for dismantling concrete structures.