JP7290969B2 - Dismantling method of reinforced concrete structure - Google Patents

Description

The present invention relates to a method for demolishing a reinforced concrete structure by electrically heating the reinforcing bars of the reinforced concrete structure.

A plurality of techniques are known as publicly known techniques as a building and dismantling method that can be dismantled by electric heating of this kind. For example, as a first known technique, a fusion-cutting reinforcing bar embedded in concrete in a substantially parallel direction, and a current-carrying reinforcing bar buried in the concrete in a direction intersecting the fusion-cutting reinforcing bar, At each crossing portion of the return line reinforcing bar embedded in the concrete in a direction that intersects each of the fusing reinforcing bars and at intervals from the conducting reinforcing bar, and the fusing reinforcing bar and the conducting reinforcing bar U-shaped grooved iron pieces, which are welded to the current-carrying reinforcing bars and embedded in the concrete, and the fusing reinforcing bars are fitted in the respective U-shaped grooves; A reinforced concrete structure having a hot water pool provided in the concrete below (Patent Document 1).

According to the reinforced concrete structure according to the first known technique, it can be dismantled with almost no noise and no vibration after use. In particular, since an iron piece having a U-shaped groove is used as the arc electrode, it can be carried out at a very low cost compared to tungsten, carbon, etc. electrodes that are generally used for arc melting work of metals.

As a second known technique, holes are drilled toward the internal reinforcing bars by a low-noise drilling machine around the demolished range of the reinforced concrete structure, the reinforcing bars are exposed and cut, and the exposed reinforcing bars are energized and heated. and weakening the concrete around the reinforcing bars in the demolished area, and then connecting the ends of the cut exposed reinforcing bars to a tensioning device and pulling them to separate and destroy the concrete in the demolished area. It is a dismantling method of things (Patent Document 2).

According to the demolition method for a reinforced concrete structure according to the second known technique, the concrete in the demolition range can be partially and surely weakened, and can be peeled and destroyed easily and with low noise. It is intended that the noise, vibration, dust, etc. can be suppressed to a low level, and that the dismantling can be carried out smoothly without causing pollution such as noise, vibration, and dust to neighboring residents, and the dismantled materials can be disposed of and transported easily.

Publication of Japanese Patent Application Laid-Open No. 53-5815 Publication of Japanese Patent Application Laid-Open No. 63-14963

In the invention of the first known technique, when constructing a concrete structure, the welding reinforcing bars arranged in advance in the vertical direction and the conducting reinforcing bars embedded in the transverse direction intersecting with each other are attached to the conducting reinforcing bars. It is an essential requirement that the welded U-shaped grooved iron piece is fitted with a reinforcing bar for fusion cutting and placed in the concrete, and it is not applied to general reinforced concrete structures that do not fit. .

In addition, in the invention of the second known technique, it is a requirement to open a hole in the reinforced concrete structure to expose and cut the reinforcing bar. It is clearly indicated that a hole is provided in each unit, and there is a problem (problem) that the workability is substantially poor and the dismantling cost is high.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dismantling method that makes it possible to dismantle concrete by weakening it at once within a required interval range, thereby improving the efficiency of the dismantling work.

As a specific means for solving the above-mentioned problems, the present invention exposes the reinforcing bars by drilling holes of the required size at the positions where the reinforcing bars of the reinforced concrete structure are arranged at the required intervals, and An output cable from a DC power supply is connected via a terminal, a current value and a voltage that become a heating temperature are set and output to the DC power supply by a control device, and the reinforcing bars are heated and expanded by energization. In addition to cracking the concrete, the strength of the concrete is reduced and the adhesion between the reinforcing steel and the concrete is reduced, so that the concrete can be crushed with a small force due to crushing. In addition to setting the temperature, it is equipped with a means for measuring the temperature of the reinforcing steel by energization and a stray current detecting means, and in the control device, the heating temperature of the reinforcing steel is input from the temperature measuring means and the power is appropriately energized. and a stray current detection signal from the stray current detection means , a stop signal is immediately sent to the DC power supply to stop the energization of the reinforced concrete. A method for dismantling a structure is provided.
In addition, as a specific means for solving the above-mentioned problems, the present invention provides a plurality of layers of reinforcing bars in the vertical direction of a reinforced concrete structure, each of which is exposed by opening holes at required intervals to expose the reinforcing bars inside the plurality of layers. An output cable from a DC power supply is connected to each of the exposed reinforcing bars through a terminal, and a current value and a voltage that become the heating temperature are set and output to the DC power supply by the control device, Simultaneous energization and simultaneous off or alternate on/off energization of the output cable causes cracks in the concrete, reduces the strength of the concrete and reduces the adhesion between the reinforcing bars and the concrete, so that the concrete can be crushed with a small force due to crushing. The control device turns on/off energization and sets the temperature by energization, and is equipped with temperature measurement means for reinforcing bars by energization and stray current detection means, and in the control device, the temperature measurement means When the stray current detection signal is input from the stray current detection means, the operation stop signal is immediately sent to the DC power supply. A dismantling method for a reinforced concrete structure is provided, characterized in that the energization is stopped by

In the above invention, the crushing is performed by compressing the concrete with attachments that operate to grip from both sides to crush and separate the concrete from the rebar; and the terminals are partially welded to the rebar; as an additional requirement.

According to the method for dismantling a reinforced concrete structure according to the present invention, the reinforcing bars are electrically heated to expand, thereby causing cracks in the concrete, weakening the concrete due to the heat, and reducing the adhesion to the reinforcing bars. Therefore, the concrete can be crushed and separated from the rebar by an attachment that works to grasp it from both sides, and the dismantling efficiency can be improved with a small force.
Furthermore, since electric heating can be carried out with almost no noise, no vibration, and little dust, there is an excellent effect that a large building can be dismantled without deteriorating the surrounding environment.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the state which opened a hole in a part of reinforced concrete structure which it is going to dismantle based on embodiment of this invention, and exposed the reinforcing bar. 1 is a schematic diagram schematically showing a model of a dismantling method according to the present invention; FIG. FIG. 3 is a perspective view showing three types of terminals in a state where an electric heating output cable used in the same dismantling method is connected to a reinforcing bar; FIG. 10 is a perspective view showing a state in which a unitized work vehicle is energized in the same dismantling method; In the dismantling method, it is sectional drawing which showed roughly the crack condition by the concrete by the reinforcing bar after electric heating, and the reinforcing bar which is not heated. FIG. 10 is a perspective view showing a situation in which cracked concrete is sequentially crushed so as to be gripped from both sides by the attachment in the dismantling method.

The present invention will be described in detail based on the illustrated embodiments.
1 to 5 showing a preferred embodiment of the present invention. First, as shown in FIG. 1, holes 2 are formed in a part of a reinforced concrete structure 1 to be dismantled at a required interval (about 7±3 m). , 3 are opened to expose the internal rebars 4 . In this case, the location of the reinforcing bar 4 in the reinforced concrete structure 1 is detected, and a hole of an appropriate size is drilled at that position using an appropriate drilling machine. It is the same as the conventional technology.

In addition, as shown in FIG. 2, the positive side output cable 8 (+) and the negative side output cable 9 (-) of the DC power supply 7 are connected to the reinforcing bars 4 exposed at a required interval through terminals 5 and 6, respectively. ). The DC power supply 7 is controlled by a control device 10 to turn on/off the current and to set the temperature by the current. , these devices are mounted on a special work vehicle 13 and unitized. The generator 14 for the DC power supply 7 may be loaded into the work vehicle 13, but if a DC power supply 7 with a large capacity is used, the generator 14 may be installed in a different location. .

Furthermore, as the terminals 5 and 6, at least three types of terminals can be used as shown in FIGS. First, FIG. (a) is a dedicated terminal 5 (6), and a round steel 17 is interposed in the center of plates (terminals) 16a and 16b that can be combined and separated by a plurality of bolts 15, and one plate (terminal ) 16a, the tip end of the round steel 17 is bent toward the other plate (terminal) 16b, and a portion of the round steel 17 maintains a straight shape along the reinforcing bar 4. The linear part is welded to the reinforcing bar 4, and when the terminal 5 (6) is to be removed, loosen the bolt 15 and leave the welded round bar 17 as it is, and pull out the plates 16a and 16b to the right side in the drawing. be. Therefore, the terminal 5 (6) can be used repeatedly if only the round steel 17 is newly added. In addition, as shown in Fig. (b), the end of the output cable 8 (9) is brought into close contact with the reinforcing bar 4, and the flat braided wire 18 of the required width is tightly wound thereon. , the flat braided wire 18 should be unwound and the output cable 8 (9) should be removed. As shown in Fig. (c), the end of the output cable 8 (9) is welded to a semi-cylindrical terminal block 19 that looks like a cylinder split in two, and the reinforcing bar 4 is held by the terminal block 19, and a plurality of screws are attached. The terminal plate 19 is attached by screwing it to the reinforcing bar 4 with a screw 20. When removing it, the terminal plate 19 can be removed by loosening the screw 20. As shown in FIG.

Next, as shown in FIG. 4, a caterpillar 21 type working vehicle is used as a special working vehicle 13, which is stopped at a position close to the reinforced concrete structure 1 to be dismantled and loaded onto the working vehicle 13. From the DC power supply 7, the plus side output cable 8 (+) and the minus side output cable 9 are connected via the terminal 5 to the reinforcing bar 4 exposed by opening the holes 2 and 3 as described above. By setting a current value or voltage of about 100 to 10,000 A, which is the decisive factor for the heating temperature, from the control unit 10 to the DC power supply 7, the reinforcing bar 4 is heated and the output status is monitored. constantly monitor the heating situation in real time, and also monitor the presence or absence of stray currents.

In this case, the current value is set in consideration of the state of the reinforced concrete structure 1 to be dismantled, the thickness and arrangement of the reinforcing bars 4, and other factors. 5, cracks 22 are generated in the concrete structure 1 due to the thermal expansion of the reinforcing bars 4, and the strength of the concrete structure 1 is lowered by heating at a high temperature, and the adhesion between the reinforcing bars 4 and concrete is reduced. It can be lowered. In the control unit 10, the heating temperature of the reinforcing bar 4 is inputted from the temperature measuring means 11, and it is monitored whether or not the current is properly energized. Then, an operation stop signal is immediately sent to the DC power supply 7 to stop the energization. In any case, the set current value and voltage are measured and monitored in real time, and the demolition work can be continued while constantly monitoring that heating is being performed by appropriate energization.

Further, as another embodiment, holes 2 and 3 are made in the same manner as described above with respect to reinforcing bars 4 in a plurality of stages in the vertical direction of the reinforced concrete structure 1 to expose the reinforcing bars 4 inside, respectively. The cracks 22 can be generated by connecting the cables 8 and 9 to the reinforcing bars 4 and energizing them at the same time. In this case, simultaneous energization and simultaneous off or alternate on/off may be repeated, and cracking may be efficiently performed by pulsation control (pulse control) of the expansion/contraction of the reinforcing bars 4 . Other embodiments and the application of pulse control can be selectively adopted depending on the state of the concrete building 1 .

In any case, as shown in FIG. 6, for the concrete structure 1 in which the cracks 22 are formed, a working vehicle 24 equipped with a dedicated attachment 23 is used to break the concrete of the concrete structure 1 with the attachment 23 on both sides. By operating to grasp and compress from the top, it is possible to crush (crushing) sequentially with a small force, efficiently crush concrete into small diameters without noise, and separate the reinforcing bars 4 and the crushed (crushed) concrete. The crushed concrete is efficiently separated, and the crushed concrete is appropriately scooped up with a scoop or the like, loaded onto a truck or the like via a conveying belt or the like, and conveyed to a predetermined location.

In the method for dismantling a reinforced concrete structure according to the present invention, holes 2 and 3 of a required size are opened at required intervals at positions where the reinforcing bars 4 of the reinforced concrete structure 1 are arranged, and the reinforcing bars 4 are exposed. Output cables 8 and 9 from a DC power supply 7 are connected to the reinforcing bars 4 through terminals 5 and 6, respectively, and the control unit 10 sets the current value and voltage that become the heating temperature to the DC power supply 7 and outputs them. Then, the reinforcing bars 4 are heated and expanded by energization, thereby causing cracks 22 in the concrete, reducing the strength of the concrete and reducing the adhesion between the reinforcing bars 4 and the concrete, so that the concrete can be crushed with a small force due to crushing. Since the structure is such as this, the concrete is cracked by energizing and heating the reinforcing bar to expand it, the concrete is weakened by the heat, and the adhesion to the reinforcing bar 4 is also reduced, so that the concrete is cracked. It can be crushed and separated from the reinforcing bar by the attachment 23 which operates as if it is gripped from both sides, and the dismantling efficiency can be improved with a small force. Since it can be carried out, it is possible to dismantle large structures without deteriorating the surrounding environment, so workability is good and cost can be greatly reduced, so it can be widely used for dismantling reinforced concrete structures in this type of industry. .

1 Reinforced Concrete Structure 2, 3 Hole 4 Rebar 5, 6 Terminal 7 DC Power Supply 8, 9 Output Cable
REFERENCE SIGNS LIST 10 control device 11 temperature measurement means 12 stray current detection means 13, 24 work vehicle 14 generator 15 bolts 16a, 16b plate (terminal)
17 Round steel 18 Flat braided wire 19 Terminal plate 20 Screw 21 Caterpillar 22 Crack 23 Attachment

Claims (4)

Drill holes of the required size at the required intervals at the positions where the reinforcing bars of the reinforced concrete structure are arranged to expose the reinforcing bars,
An output cable from a DC power supply is connected to each of the exposed reinforcing bars via a terminal,
Setting and outputting a current value and a voltage that become the heating temperature in the control device for the DC power supply,
Electricity causes the reinforcing bars to heat and expand, causing cracks in the concrete, reducing the strength of the concrete, and reducing the adhesion between the reinforcing bars and the concrete.
It is possible to crush concrete with a small force by crushing,
The control device performs on/off of energization and temperature setting by energization, and is equipped with means for measuring the temperature of reinforcing bars by energization and means for detecting stray current,
In the control device, when the heating temperature of the reinforcing steel is input from the temperature measuring means and the current is properly energized, it is monitored, and when the detection signal of the stray current is input from the stray current detecting means, immediately. A dismantling method for a reinforced concrete structure, characterized in that the demolition method of a reinforced concrete structure is configured to transmit an operation stop signal to the DC power supply to stop the energization . Holes are drilled at required intervals in multiple levels of reinforcing bars in the vertical direction of a reinforced concrete structure to expose the internal reinforcing bars,
An output cable from a DC power supply is connected to each of the multiple stages of exposed reinforcing bars via a terminal,
Setting and outputting a current value and a voltage that become the heating temperature in the control device for the DC power supply,
By simultaneously energizing and simultaneously turning off or alternately turning on and off the output cables of each stage, cracks are generated in the concrete, the strength of the concrete is reduced, and the adhesion between the reinforcing bars and the concrete is reduced,
It is possible to crush concrete with a small force by crushing,
The control device performs on/off of energization and temperature setting by energization, and is equipped with means for measuring the temperature of reinforcing bars by energization and means for detecting stray current,
In the control device, when the heating temperature of the reinforcing steel is input from the temperature measuring means and the current is properly energized, it is monitored, and when the detection signal of the stray current is input from the stray current detecting means, immediately. It is configured to stop energization by sending an operation stop signal to the DC power supply.
A method for dismantling a reinforced concrete structure, characterized by : The method for dismantling a reinforced concrete structure according to claim 1 or 2, wherein the crushing is performed by compressing the concrete with attachments that operate to grip from both sides to crush the concrete and separate it from the reinforcing bars. The method for dismantling a reinforced concrete structure according to claim 1 or 2, wherein the terminals are partially welded to the reinforcing bars.

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