JP4170541B2 - Demolition method of concrete building - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for demolishing a concrete building, and more particularly, to a method for destroying a frame covered with a finishing layer of a concrete building.
[0002]
[Prior art]
Conventionally, in order to destroy a casing of a concrete building, a weak direct current is passed through the casing through the surface of the casing and a reinforcing bar in the casing, thereby deteriorating a part of the casing. Yes. The rebar is used as a positive electrode for energization, and a negative electrode assembly is disposed on the surface of the housing. The negative electrode assembly includes a container having an open end surface in contact with the housing, an electrolytic solution accommodated in the container, and an electrode plate immersed in the electrolytic solution.
[0003]
According to this, since a part of the deteriorated casing is more fragile than before deterioration, it can be easily destroyed.
[0004]
In addition, it has been proposed that the conventional case is destroyed by making a plurality of holes in a deteriorated region and filling these holes with an expansion agent. According to this, a large number of cracks are generated in the fragile portions between the holes due to the expansion pressure with respect to the peripheral wall surface of the holes due to the volume expansion of the expansion agent over time, and the deteriorated region is statically crushed.
[0005]
By the way, when the surface of the housing is covered with a finishing layer such as a mortar layer, it is considered that the finishing layer is crushed and peeled off to energize the housing to expose the surface of the housing. It is done. However, this takes time and labor, and causes a reduction in efficiency of the destruction work of the frame. In addition, the replenishment work of the electrolyte solution leaking from between the open end face of the container for the electrode plate and the finishing layer also causes the efficiency of the work of destroying the housing to be reduced.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to increase the efficiency of the demolition work of a concrete building.
[0007]
[Means for Solving the Problems]
The present invention is a method for demolishing a concrete building having a casing covered with a finishing layer, wherein a plurality of first holes reaching the surface of the casing are formed in the finishing layer, and the finishing layer and the Forming a second hole in each of the housings to reach a reinforcing bar in the housing; passing a direct current through the housing through the surface of the housing and the reinforcing bar exposed in the first and second holes, respectively; Producing a deteriorated region in contact with each other or partially overlapping, and then forming a third hole connected to the first hole in the deteriorated region of the housing, and filling the third hole with an expansion agent Including that.
[0008]
The expansion agent can also be filled into a first hole that is continuous with the third hole.
[0009]
In order to energize the housing, a container having an open side surface to which a flexible sealing material in contact with the finishing layer is attached, and is immersed in the electrolytic solution filling the plurality of first holes. A container in which the electrode plate is accommodated can be disposed.
[0010]
Operation and effect of the invention
According to the present invention, the surface of the casing for energization is exposed by forming the first hole in the finishing layer covering the surface of the casing, and the energization of the casing through the first hole is performed. It is possible to obtain a deteriorated region that is in contact with each other or partially overlapping and continuing. This eliminates the need for crushing and removing the finishing layer, thereby enabling the work required for breaking the casing to be performed quickly and efficiently.
[0011]
The casing can be crushed silently and without any extra effort due to the occurrence of cracks in the portion between the third holes due to the volume expansion action of the expansion agent over time. In addition, when filling the expansion agent also in the first hole connected to the third hole, the volume expansion action of the expansion agent is exerted on the portion between the first holes, and the finishing layer is crushed. Can be performed simultaneously, and thereby, the demolition work of the concrete building can be made more efficient.
[0012]
Since the electrode plate connected to the surface of the casing and the container containing the electrolytic solution have an open side surface to which a flexible sealing material in contact with the finishing layer is attached, the open side surface of the container The sealing material closely follows the unevenness of the surface of the finishing layer, so that leakage of the electrolyte solution from between the open side surface of the container and the finishing layer and interruption of the energization associated therewith are avoided. By this, it is possible to realize a more efficient dismantling of a concrete building.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown a reinforced concrete frame 12 made up of columns and walls that form a part of a concrete building 10 (only a part of which is shown) that is to be demolished according to the present invention.
[0014]
Both surfaces 13 of the housing 12 are covered with a finishing layer 14, for example, a mortar layer 16, and a wallpaper 18 adhered to the mortar layer 16. The casing 12 may be one in which only one surface is covered with the finishing layer 14. A plurality of reinforcing bars 20 extending in the vertical direction are embedded in the housing 12.
[0015]
In applying the disassembling method according to the present invention, first, a plurality of holes (first holes) 22 reaching each surface 13 of the housing 12 are formed in the finishing layer 14, and these are formed in both the finishing layer 14 and the housing 12. Then, a hole (second hole) 24 reaching the reinforcing bar 20 in the housing 12 is formed. For example, in the case of a casing made of a wall, the surface of the casing 12 in which the first hole 22 is formed may be either the entire area of the wall surface or a partial area thereof.
[0016]
By making the first and second holes 22 and 24, a part of the surface 13 of the housing and a part of the reinforcing bar 20 are exposed in these holes, respectively.
[0017]
The formation of the first hole 22 eliminates the need for crushing and removing the finishing layer 14 for energization described later and formation of a degraded region described later.
[0018]
The arrangement of the plurality of first holes 22 can be, for example, staggered (see FIG. 2). The first and second holes 22 and 24 can be formed using a drilling device (not shown) such as an ultrasonic drill.
[0019]
Next, a weak direct current is passed through the housing 12 through a part of the surface 13 of the housing exposed in the first and second holes 22 and 24 and a part of the reinforcing bar 20. For this purpose, an electrode plate (cathode plate) 26 is arranged, and the reinforcing bar 20 is used as the positive electrode 28.
[0020]
The cathode plate 26 is made of a wire mesh. The cathode plate 26 is disposed in a container 30 fixed to the finishing layer 14 and is opposed to the plurality of first holes 22 that open to the surface of the finishing layer 14.
[0021]
The cathode plate 26 is connected to a DC power source (not shown) via a cable 31 extending through an open upper end 36, which will be described later, and the positive electrode 28 is connected to a DC power source (not shown) via a cable 32 extending in the second hole 24. Has been.
[0022]
The container 30 in which the cathode plate 26 is disposed is formed of a flat box-like body made of a plastic material such as vinyl chloride resin, and has an open side 34 facing the surface of the finishing layer 14 and an open upper end 36. Have.
[0023]
A strip-shaped sealing material (not shown) extending along the open side surface 34 of the container 30 is attached by adhesion.
[0024]
The sealing material is made of, for example, hard rubber and has flexibility. In the illustrated example, an adhesive (not shown) is applied to the surface of the sealing material, and the container 30 is liquid-tightly fixed to the surface of the finishing layer 14 via the adhesive.
[0025]
Thereby, the container 30 defines the accommodation space for the electrolyte solution described later in cooperation with the surface of the finishing layer 14. The flexible sealing material is deformed following the irregularities on the surface of the finishing layer 14 and is in close contact therewith, so that higher liquid tightness can be imparted.
[0026]
The container 30 contains an electrolytic solution 38 such as a magnesium chloride solution that is supplied from the open upper end 36 and is supplied as necessary.
[0027]
The cathode plate 26 in the container 30 is entirely immersed in the electrolyte 38. Each first hole 22 is filled with the electrolytic solution 38, and the surface 13 of the housing 12 is in contact with the electrolytic solution 38. For this reason, the cathode plate 26 is connected to the surface 13 of the housing 12 via the electrolytic solution 38, and the electrolytic solution 38 penetrates into the interior of the housing 12 from the surface.
[0028]
Next, a direct current is passed from the power source to the housing 12 through the cathode plate 26 and the positive electrode 28, and a part of the housing 12 (more specifically, a portion between the reinforcing bar 20 and each first hole 22) is energized. To do. As a result, a large number of small cracks are formed in the part of the casing 12 due to expansion due to the progress of corrosion of the reinforcing bars 20 due to electrolysis of the electrolytic solution 38 that has penetrated into the casing 12 and the pressure of oxygen generated during electrolysis. As a result, a part of the housing 12 is deteriorated.
[0029]
That is, a plurality of deteriorated regions 40 (shown by imaginary lines in FIG. 2) that are weaker than other portions (healthy portions) are generated. The substantially columnar weakened portion extending from each reinforcing bar 20 to the finishing layer 14 can be easily broken with a smaller force than the healthy portion.
[0030]
For example, as shown in FIG. 2, the energization is performed by applying a current of 0.6 to 1.0 A / m for 7 to 14 days under a voltage of 50 V per 10 cm in width.
[0031]
These deteriorated regions 40 are partially overlapped with each other or connected in contact with each other. The mode of connection between the deteriorated regions 40 or the radius of the deteriorated regions can be changed by changing the diameter of the first holes 22, the mutual interval between the first holes 22, the magnitude of the applied current, and the like.
[0032]
After the degradation region 40 is generated, the electrode plate 26 and the container 30 are removed, and a hole (third hole) 42 (only one of which is indicated by an imaginary line) is formed in each degradation region 40. The hole 42 can be formed by inserting the drill from the first hole 22 and cutting the housing 12.
[0033]
Thereafter, an expansion agent (illustrated) is filled from the first hole 22 into the third hole 42. Preferably, the swelling agent is made by mixing water and kneaded with a drug mainly composed of an inorganic compound mainly composed of quicklime and silicate (for example, “Brighter” manufactured by Onoda Co., Ltd.). Reacts with water (hydration reaction) so that its volume expands over time.
[0034]
Other examples of the expanding agent include calcined dolomite, magnesia, ordinary Portland cement-blast furnace slag-bauxite-gypsum, alumina cement-lime-gypsum.
[0035]
Due to the volume expansion of the expansion agent in each hole 42, the peripheral wall surface of the hole 42 receives an expansion pressure in the radial direction. The “blister” has a volume expansion coefficient of about 3 times. Cracks extending from one hole 42 toward the other hole 42 due to a change in the volume of the expansion agent in the inter-parts of the third holes 42, that is, in both deterioration regions 40 around the third holes 42 adjacent to each other. (Not shown) occurs.
[0036]
Thereby, the housing 12 can be crushed statically and without labor. The crushed housing 12 can be broken together with the finishing layer 14 by applying a small force to the finishing layer 14.
[0037]
In addition to the third hole 42, the first layer 22 connected to the hole is filled with the expansion agent, so that the finishing layer 14 can be crushed at the same time. It can be made easier.
[Brief description of the drawings]
FIG. 1 is a partial longitudinal sectional view of a frame and a finishing layer of a concrete building.
FIG. 2 is a partial front view of a finishing layer obtained by cutting out a container containing an electrolytic solution.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Concrete building 12 Housing 14 Finishing layer 20 Reinforcing bar 22,24,42 1st, 2nd and 3rd hole 26,28 Cathode plate and positive electrode 30 Container 38 Electrolyte

Claims (3)

A method of demolishing a concrete building having a casing covered with a finishing layer, wherein a plurality of first holes reaching the surface of the casing are formed in the finishing layer, and both the finishing layer and the casing are formed. Forming a second hole reaching the reinforcing bar in the casing, passing a direct current through the casing through the surface of the casing and the reinforcing bar exposed in the first and second holes, respectively, and contacting or contacting the casing with each other Generating overlapping deterioration regions, and then forming third holes in the deterioration region of the housing that are continuous with the first holes, and filling the third holes with an expansion agent. A method for dismantling concrete buildings. The method according to claim 1, further comprising filling the first hole connected to the third hole with the expansion agent. In order to energize the housing, a container having an open side surface to which a flexible sealing material in contact with the finishing layer is attached, and is immersed in the electrolytic solution filling the plurality of first holes. The method according to claim 1, wherein a container containing an electrode plate is disposed.

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