JP5374991B2 - Reinforced concrete structure dismantling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the time of work in demolishing a reinforced concrete structure by a crushing method. <P>SOLUTION: In the method for demolishing a reinforced concrete structure, shear reinforcements 14 surrounding and winding on axial reinforcements 12, 16 of the reinforced concrete structure are cut with a cutting means such as a wall saw, and then the reinforced concrete structure is crushed with a crushing means such as a crushing attachment or the like removably installed on a heavy machine. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a reinforced concrete structure dismantling method.

  For reinforced concrete structures, a demolition method is generally used in which a blade of a crusher is opened and closed by hydraulic pressure and crushed while sandwiching reinforced concrete. However, in this crushing method, when the amount of reinforcing steel in the reinforced concrete is large, even if the concrete portion inside the reinforced concrete is crushed, it may be restrained by the shear reinforcement of the beam or column and may not be reliably disassembled. In such a case, in order to reliably dismantle the reinforced concrete, it is necessary to spread or cut the shear reinforcement bars, but in this case, there is a problem that the efficiency of the dismantling work is deteriorated and the work time is required. .

On the other hand, Patent Document 1 discloses a dismantling method in which a concrete portion of reinforced concrete is broken by an impact force generated by instantaneously vaporizing a breaking solution and an exposed reinforcing bar is cut. However, in this dismantling method, it is necessary to provide a mounting hole in the concrete in order to mount the breaking solution, and this is not necessarily an efficient dismantling method.
JP 7-317330 A

  The present invention has been made in view of such conventional problems, and an object of the present invention is to shorten the working time when dismantling a reinforced concrete structure by a crushing method.

In order to achieve this object, the invention shown in claim 1 is a method of dismantling a reinforced concrete structure,
After the shear reinforcement bar wrapped around the axial direction reinforcing bar of the reinforced concrete structure is cut in the axial direction by a cutting means,
The reinforced concrete structure dismantling method, wherein the reinforced concrete structure is crushed by a crushing means.
According to the first aspect of the present invention, the reinforced concrete can be easily destroyed by weakening the concrete restraining function of the shear reinforcement by cutting the shear reinforcement. Thereby, when dismantling a reinforced concrete structure by a crushing method, working time can be shortened compared with the conventional construction method which does not cut | disconnect a shear reinforcement bar prior to crushing.

Invention of Claim 2 is the reinforced concrete structure demolition construction method of Claim 1,
The reinforced concrete structure comprises two or more axial rebars;
In the reinforced concrete structure dismantling method, the shear reinforcing bar is cut at any one of the longest intervals among the spaces between the axial reinforcing bars adjacent to each other on the same surface side is there.
According to the second aspect of the present invention, it is possible to more effectively reduce the work time when the reinforced concrete structure is dismantled by the crushing method by cutting the shear reinforcing bar at a location where the reinforcing bar density is low and the strength is relatively weak. It can be shortened.

Invention of Claim 3 is the reinforced concrete structure demolition construction method of Claim 1 or 2,
The axial rebar is a reinforced concrete structure dismantling method characterized in that it is a main rebar.
According to the third aspect of the present invention, when a reinforced concrete beam is dismantled by the crushing method, the dismantling work time can be shortened by cutting the shear reinforcement bars surrounding the main bars.

Invention of Claim 4 is the reinforced concrete structure demolition construction method in any one of Claims 1-3,
The shear reinforcing bar is a reinforced concrete structure dismantling method characterized in that it is a beam bar.
According to the fourth aspect of the present invention, when a reinforced concrete beam is dismantled by the crushing method, the dismantling operation time can be shortened by cutting the reinforcing bar of the beam.

Invention of Claim 5 is the reinforced concrete structure demolition construction method of Claim 4,
It is a reinforced concrete structure dismantling method characterized in that the reinforcing bar is cut by cutting from the side of the beam along the axial direction from end to end of the beam .
According to the fifth aspect of the present invention, when a reinforced concrete beam is dismantled by a crushing method, the beam is cut from the side of the beam along the axial direction from the end of the beam to the end. The muscle can be cut and the dismantling operation time can be shortened more effectively.

Invention of Claim 6 is the reinforced concrete structure demolition construction method in any one of Claims 1-3,
The shear reinforcing bar is a reinforced concrete structure dismantling method characterized in that the reinforcing bar is a column band.
According to the sixth aspect of the present invention, when a reinforced concrete column is dismantled by the crushing method, the dismantling work time can be shortened by cutting the column streaks.

Invention of Claim 7 is the reinforced concrete structure dismantling method in any one of Claims 1-6,
The cutting means is a reinforced concrete structure dismantling method characterized in that it is a wall saw.
According to the seventh aspect of the present invention, the shear reinforcement can be cut in a short time and at a low cost. Also, since no fire is used, there is no risk of fire and there are no flying objects, so it is safe. Furthermore, although there is noise, there is almost no vibration and dust, so there is almost no adverse effect on the surrounding environment of the demolition work site.

The invention shown in claim 8 is the reinforced concrete structure dismantling method according to any one of claims 1 to 6,
The cutting means is a reinforced concrete structure dismantling method characterized in that it is a cutting attachment that can be attached to and detached from a heavy machine.
According to the eighth aspect of the present invention, the shear reinforcement can be cut in a short time. Also, since no fire is used, there is no risk of fire and there is almost no scattered matter, so it is safe. Furthermore, although there is noise, there is almost no vibration and dust, so there is almost no adverse effect on the surrounding environment of the demolition work site.

Invention of Claim 9 is the reinforced concrete structure dismantling method in any one of Claims 1-8, Comprising : The said cutting | disconnection means is the said shear reinforcement bar in the position which avoided the vicinity of the said axial rebar. A reinforced concrete structure dismantling method characterized by cutting in the axial direction .

  The work time when the reinforced concrete structure is dismantled by the crushing method can be shortened.

=== First Embodiment ===
FIG. 1 is a cross-sectional view of a beam 10 made of reinforced concrete to be demolished using the reinforced concrete structure dismantling method of the present invention. As shown in the figure, the beam 10 includes a main muscle 12, a gluteal muscle 14, and an abdominal muscle 16 inside, and the other parts are mainly made of concrete.
The main muscles 12 and the abdominal muscles 16 are axial rebars referred to in the claims. Further, the main muscle 12 includes an upper end muscle 12a on the top end (upper surface) side and a lower end muscle 12b on the bottom end (lower surface) side. The abdominal muscle 16 is disposed on the side surface side of the beam 10 and between the upper end muscle 12a and the lower end muscle 12b.

Hereinafter, a procedure for disassembling the beam 10 using the reinforced concrete structure dismantling method of the present invention will be described.
First, as shown by the arrows in FIG. 1, the beam 10 is cut from end to end in the axial direction of the beam 10 by a cutting means (not shown) such as a wall saw. When making this cut, the concrete is cut together with the reinforcing bar 14.
In general, it is preferable to make the cut into the beam 10 from the side where the reinforcing bar density is low and the strength is weak, but it may be made from the top or bottom.

  When a cut is made on the side surface, the cut portion may be any portion of the space sandwiched between the upper muscle 12a and the lower muscle 12b on the same side, but the vicinity of the upper muscle 12a and the lower muscle 12b should be avoided. preferable. In addition, when the abdominal muscle 16 is about the same thickness as the main muscle 12, it is preferable to avoid the vicinity of the abdominal muscle 16 as a location to cut.

  When making a cut at the top end, the place where the cut is made may be any place in the space between the two upper end stripes 12a, but it is preferable to avoid the vicinity of the upper end stripe 12a. When making a notch in the bottom end, the place where the notch is made may be any place in the space between the two lower end stripes 12b, but it is preferable to avoid the vicinity of the lower end stripe 12b.

  Next, the beam 10 is disassembled by crushing the cut beam 10 by a crushing means (not shown) such as a crushing attachment (hereinafter referred to as “crusher”) that can be attached to and detached from a heavy machine. It should be noted that the reinforcing bars such as main bars connected to the walls and columns are separated from the walls and columns by cutting them with a crusher. Rebars such as main bars may be burned out by a burner (not shown).

  Moreover, below, the comparative experiment of the reinforced concrete structure dismantling method of 1st Embodiment and the conventional method was done. FIG. 2 is a table showing the specifications of the reinforced concrete beam 10 used in this comparative experiment. 3A is an explanatory view of the beam 10 for showing the arrangement of the upper end bars 12a of the main bars 12 as viewed from above. FIG. 3B shows the beam 10 for showing the arrangement of the lower end bars 12b of the main bars 12 below. It is explanatory drawing seen from. As shown in FIGS. 2 and 3, the length of the beam 10 is 4200 mm, and the upper rebar of the beam 10 has two rebars with a diameter of 25 mm at the central and outer end portions and a rebar with a diameter of 25 mm at the inner end portion. Three lower bars are provided with three reinforcing bars with a diameter of 25 mm at the central part, two reinforcing bars with a diameter of 25 mm at both end parts, two abdominal muscles with two 10 mm reinforcing bars, and Reinforcing bars with a diameter of 10 mm are arranged so as to surround the main muscles 12 and the abdominal muscles 16 at intervals of 200 mm.

  Moreover, FIG. 4A-FIG. 4C are the figures which show the location which makes a cut | incision in the beam 10 with an arrow, respectively. In the pattern shown in FIG. 4A, a cut is made at one place on one side surface (hereinafter referred to as “pattern A”). In the pattern shown in FIG. 4B, a cut is made in two places, one on each side surface (hereinafter referred to as “pattern B”). In the pattern shown in FIG. 4C, a cut is made in one place at the top (hereinafter referred to as “pattern C”). Here, the cut bar 14 is cut together with the concrete in any pattern. Further, the pattern A and the pattern B are notched in the vicinity of the middle of the upper end stripe 12a and the lower end stripe 12b on the same side.

  Under the above preconditions, an experiment was conducted to compare the time required for crushing in the case of the conventional construction method in which no cut is made and in the case where three patterns of cut are made in the beam 10. FIG. 5 is a table showing the time required for crushing and the shortening rate in four cases of the conventional method and patterns A to C. Here, the time reduction rate is a value obtained by dividing the time required for the conventional method by the time required for each pattern, assuming that the conventional method is 100%. As shown in FIG. 5, the conventional method required 6 minutes and 45 seconds, but pattern A was 5 minutes and 43 seconds (time reduction rate improved by 18%), pattern B was 5 minutes and 36 seconds (time reduction rate improved by 21%), pattern In C, 6 minutes and 25 seconds (time reduction rate improved by 5%), and according to the method of the present invention, the crushing time of any pattern could be shortened compared to the conventional method. In particular, the time shortening effect of about 20% was obtained for the patterns A and B.

  Here, it is necessary to make a cut in the reinforced concrete before the crushing operation, but the experimental result in FIG. 5 does not include the time required for cutting. This is because cutting work is performed prior to crushing work such as assembly of work scaffolds, reinforcement to prevent the reinforced concrete structure from collapsing during dismantling work, and introduction of heavy equipment crusher as crushing means. Since it is performed in parallel, adding the cutting work to the conventional method does not affect the total work time of the dismantling work. Therefore, it is not necessary to consider the time required for cutting.

  As mentioned above, according to the reinforced concrete structure dismantling method of 1st Embodiment, the time required for crushing can be shortened rather than the conventional method. That is, in the conventional method, when the reinforced concrete beam 10 is disassembled, the beam 10 is simply crushed by the crushing means without performing the preceding process such as cutting, and the concrete crushed by the crushing means is crushed. Even after being done, the integrity is maintained by being restrained by the gluteal muscle 14, so that it was not possible to crush efficiently. However, according to the reinforced concrete structure dismantling method of the first embodiment, since the rebar 14 is cut before crushing, the crushed concrete collapses without being restrained by the rebar 14 when the beam 10 is crushed. It can be demolished efficiently.

  In consideration of the time shortening effect, among the three patterns from pattern A to pattern C, pattern C can only obtain a time shortening effect of about 5%, so the other two that can obtain a time shortening effect of about 20%. It can be said that it is more preferable.

  Furthermore, when the amount of time required for the cutting operation and the time reduction effect obtained are comparatively weighed, it can be said that the pattern A is more preferable than the pattern B. That is, both the pattern A and the pattern B can obtain a time shortening effect of about 20%, so there is no great difference in terms of the time shortening effect, but if the cut is increased from one place to two places, the labor is doubled. Therefore, the pattern A is the most preferable in view of the labor of the work, although it does not affect the total work time of the dismantling work.

=== Other Embodiments ===
As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The deformation | transformation as shown below is possible in the range which does not deviate from the summary.

  In the first embodiment, the reinforced concrete structure to be demolished is the beam 10, but the reinforced concrete demolition method of the present invention can be used even for a column. In this case, a cut is made in the concrete to cut the band in the column.

  In the first embodiment, a wall saw is used as the cutting means. However, the present invention is not limited to this. For example, a water jet method may be used. Moreover, you may cut | disconnect by exposing a shear reinforcement bar | burr by shaving the surface of concrete with a manual breaker, and fusing the shear reinforcement bar | burr.

  Moreover, you may use the cutting attachment which can be attached or detached to a heavy machine as a cutting | disconnection means. In this case, if the cutting attachment is replaced with a crushing attachment after the cutting operation is completed, the disassembling operation can be efficiently performed.

  In the first embodiment, the demolition work of the reinforced concrete structure has been described. However, the reinforced concrete structure demolition method of the present invention can also be used for steel reinforced concrete.

It is sectional drawing of the beam 10 made from reinforced concrete demolished using the reinforced concrete structure dismantling method of this invention. It is a table | surface which shows the specification of the beam 10 of the reinforced concrete used for this comparative experiment. FIG. 3A is an explanatory view of the beam 10 for showing the arrangement of the main bars of the beam 10 from above, and FIG. 3B is an explanatory view of the beam 10 for showing the arrangement of the main bars of the beam 10 from below. is there. It is a figure which shows the location which makes a notch in the beam. It is a table | surface which shows the crushing required time and the shortening rate in the case of four methods, a conventional construction method and the patterns A-C.

Explanation of symbols

10 beam 12 main muscle 14 gluteal muscle 16 abdominal muscle

Claims (9)

A method of dismantling reinforced concrete structures,
After the shear reinforcement bar wrapped around the axial direction reinforcing bar of the reinforced concrete structure is cut in the axial direction by a cutting means,
A method for dismantling a reinforced concrete structure, wherein the reinforced concrete structure is crushed by a crushing means. The reinforced concrete structure dismantling method according to claim 1,
The reinforced concrete structure comprises two or more axial rebars;
A method for dismantling a reinforced concrete structure, wherein the shear reinforcing bars are cut at any one of the longest intervals among the spaces between the axial reinforcing bars adjacent to each other on the same plane side. It is a reinforced concrete structure dismantling method according to claim 1 or 2,
Reinforced concrete structure dismantling method, wherein the axial reinforcing bars are main reinforcing bars. The reinforced concrete structure dismantling method according to any one of claims 1 to 3,
The method of dismantling a reinforced concrete structure, wherein the shear reinforcement is a bar reinforcement. The reinforced concrete structure dismantling method according to claim 4,
A method for dismantling a reinforced concrete structure , wherein the reinforcing bar is cut by cutting from the side of the beam along the axial direction from end to end of the beam . The reinforced concrete structure dismantling method according to any one of claims 1 to 3,
The method for dismantling a reinforced concrete structure, wherein the shear reinforcing bar is a column reinforcing bar. The reinforced concrete structure dismantling method according to any one of claims 1 to 6,
The method for dismantling a reinforced concrete structure, wherein the cutting means is a wall saw. The reinforced concrete structure dismantling method according to any one of claims 1 to 6,
The method for dismantling a reinforced concrete structure, wherein the cutting means is a cutting attachment that can be attached to and detached from a heavy machine. A reinforced concrete structure dismantling method according to any one of claims 1 to 8 ,
The method for disassembling a reinforced concrete structure, wherein the cutting means cuts the shear reinforcing bar in the axial direction at a position avoiding the vicinity of the axial reinforcing bar.

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