JP7628449B2 - Surface layer separation method for concrete structures - Google Patents

Description

The present invention relates to a method for surface layer separation of a concrete structure.

When demolishing a concrete structure, buildings whose interior walls have been exposed to radioactive materials are the target of demolition, and as a result of the penetration of the radioactive materials, contaminated areas occur on the surface of the interior walls of the building, which necessitates work to separate these contaminated areas. The separated, contaminated surface layer and the remaining areas are treated as different types of waste, so work to separate the surface layer of the interior walls is required. This surface layer separation work must be carried out in a way that prevents secondary contamination from dust generated from the surface layer. In other words, it must be carried out in a way that prevents the generation and scattering of dust.

Patent Document 1 shows a method for removing the surface layer of a portion of a concrete structure contaminated by radioactive materials. In this method, a wall saw is used to form a gate-shaped groove along the portion to be removed on the inner wall of the structure contaminated by radioactive materials, and then the wall saw is used to widen the lower left and right portions of the gate-shaped groove, and a pair of guide pulleys is installed at each widened portion. The axis of each guide pulley is perpendicular to the opening direction of the groove. In addition, the axis of this guide pulley is freely rotatable around an axis along the opening direction of the groove, that is, the orientation of the guide pulley is freely changeable. An endless wire saw is installed so that part of it is contained within the groove and the other part is pulled out to the outside of the groove via the guide pulley and connected to a driving machine, and the portion to be removed is cut vertically.

This cutting is done so that the cut surface comes close to the guide pulley, and the space in the widened groove is used to change the orientation of the guide pulley to follow the change in the extension direction of the wire saw near the guide pulley as the cutting progresses. However, widening the groove width as described above is time-consuming. Also, there is a concern that the guide pulley will not be able to follow the change in the extension direction of the wire saw, and the wire saw will come off the guide pulley.

Japanese Unexamined Patent Publication No. 2-225006

The present invention was made in consideration of these circumstances, and aims to prevent the surface layer of a concrete structure from turning into dust and scattering when separating the surface layer, and to prevent an increase in the amount of work required.

The separation method of the present invention is a method for separating a surface layer of a concrete structure by using an endless wire saw, comprising the steps of:
a groove forming step of cutting a periphery of a region to be separated that forms the surface layer to form a first groove surrounding the region to be separated;
a first installation step of installing first and second guide pulleys in the first groove so as to sandwich a surface layer on one of the left and right sides of the region to be separated from the front and rear and so that an outer circumferential surface of the first guide pulley faces a bottom surface of the first groove;
a first cutting step of cutting and separating the surface layer by using the wire saw so as to be wound around the surface layer on the other side of the region to be separated, and to be stretched across the first and second guide pulleys and pulled out to the outside of the first groove;
a second installation step of installing the first and second guide pulleys in a first recess formed by separating the surface layer in the first cutting step such that an outer circumferential surface of the first and second guide pulleys faces a bottom surface of the first recess;
a second cutting step of cutting and separating the surface layer by using the wire saw so as to be wound around the surface layer on one of the left and right sides of the region to be separated and to be stretched across the first and second guide pulleys and drawn out to the outside of the first recess;
Equipped with
the separation target region is a surface layer of the adjacent inner walls, which are the floor wall and the side wall or the ceiling wall and the side wall, among the floor wall, the side wall, and the ceiling wall, which are the inner walls of a room;
the groove forming step includes a step of forming the first groove on the inner side of a periphery of each of the adjacent inner walls,
a step of repeatedly performing the groove forming step, the first setting step, the first cutting step, the second setting step, and the second cutting step to form a second recess in each of the adjacent inner walls;
a separation process of forming second grooves extending from within each of the second recesses toward the outside of the second recesses along the periphery of each of the adjacent inner walls and connecting the second grooves formed in each of the adjacent inner walls to each other, and separating the periphery of the surface layer of the adjacent inner walls from the concrete structure;
Includes.

According to the present invention, it is possible to cut the surface layer of a concrete structure to the desired thickness without shattering it. Furthermore, the burden of installing a guide pulley across which the wire saw is hung during cutting is small. Therefore, it is possible to prevent the surface layer of the concrete structure from turning into dust and scattering, and to prevent an increase in the amount of work required.

1 is a process diagram showing a procedure for separating an inner wall of a room according to an embodiment of the present invention. 5A to 5C are process diagrams showing a procedure for separating the inner wall. 5A to 5C are process diagrams showing a procedure for separating the inner wall. 5A to 5C are process diagrams showing a procedure for separating the inner wall. 5A to 5C are process diagrams showing a procedure for separating the inner wall. 5A to 5C are process diagrams showing a procedure for separating the inner wall. 5A to 5C are process diagrams showing a procedure for separating the inner wall. 5A to 5C are process diagrams showing a procedure for separating the inner wall. FIG. 2 is a front view showing a wall saw machine used in the process of separating the inner wall. FIG. 4 is a perspective view showing a wire saw machine used in the step of separating the inner wall. 2 is a side view showing a guide pulley and a wire saw that constitute the wire saw machine. FIG. 2 is a side view showing a guide pulley and a wire saw that constitute the wire saw machine. FIG. FIG. 4 is a process diagram of a process performed using the wire saw machine. FIG. 4 is a process diagram of a process performed using the wire saw machine. FIG. 4 is a process diagram of a process performed using the wire saw machine. FIG. 4 is a process diagram of a process performed using the wire saw machine. FIG. 4 is a plan view showing a ceiling surface forming the inner wall. 5 is a process diagram showing a procedure for separating the peripheral surface layer of the inner wall. FIG. 5 is a process diagram showing a procedure for separating the peripheral surface layer of the inner wall. FIG. 5 is a process diagram showing a procedure for separating the peripheral surface layer of the inner wall. FIG. FIG. 2 is a vertical cross-sectional view of a corner of the room. FIG. 2 is a vertical cross-sectional view of a corner of the room. FIG. 2 is a top view of a wire saw machine used in a comparative example technique. FIG. 4 is a side view of a guide pulley of a wire saw machine used in the method of the comparative example.

An outline of one embodiment of the present invention will be described below with reference to Figs. 1 to 8. As described in the Background Art section, this embodiment shows the steps of work carried out in the process of demolishing a building 10, which is a concrete structure whose inner walls are contaminated with radioactive materials. More specifically, the process shows the separation of the surface layers of the concrete inner walls (floor walls 13, side walls 14, and ceiling wall 15) of a square room 11 in the building 10. Figs. 1 to 8 are diagrams of the process and are also plan views of the room 11. In the following description, the surface layers of the inner walls contaminated with radioactive materials will be referred to as the contaminated surface layers. In the figures, the contaminated surface layers of the floor walls 13 of the room 11 are indicated by a number of dots.

First, a portion of the wall surface of the floor 13 of the room 11 is defined as a rectangular area to be separated 21 (Figure 1). This area to be separated 21 is the area where the contaminated surface layer will be cut later using the wire saw machine 4, and is defined to be a size that allows cutting by the wire saw machine 4. For ease of explanation, the length direction of the area to be separated 21 will be defined as the left-right direction, and the width direction will be defined as the front-rear direction.

Then, the outer periphery of the region to be separated 21 is cut with a wall saw machine 3 to form two narrow grooves 22 (Figure 2). The two narrow grooves 22 are formed in a rectangular ring shape in plan view so as to surround the region to be separated 21, and are close to each other. After that, the two narrow grooves 22 are processed to be connected, forming a rectangular ring-shaped groove 23 (first groove) (Figure 3).

After the groove 23 is formed, a wire saw machine 4 is installed on the floor wall 13, and the groove 23 is used to cut and separate the contaminated surface layer of the region to be separated 21 (Figures 4 and 5). As this will be explained in detail later, a detailed explanation will be omitted here, but this cutting of the contaminated surface layer is performed in two stages, cutting one side of the left and right of the region to be separated 21, then the other. After one cut, the position of the wire saw machine 4 is changed. The region to be separated 21, from which the contaminated surface layer has been separated by performing two cuts in this way, is shown in Figure 5 as the contaminated surface layer separation region 20.

Then, the area of the floor wall 13 where the contaminated surface layer remains is designated as the new separation target area 21, and the same series of steps as described above are repeated (Figure 6). During this time, the area from which the contaminated surface layer has been separated is appropriately protected by covering it with a vinyl sheet, for example. Then, once separation of the contaminated surface layer of the floor wall 13 is completed, the same steps as those described in Figures 2 to 6 are performed on the side wall 14 and ceiling wall 15 to separate the contaminated surface layer.

The above process separates most of the contaminated surface layer, but the contaminated surface layer remains on the periphery of each of the floor wall 13, side wall 14, and ceiling wall 15 for reasons that will be described later. By separating the contaminated surface layer except for the periphery, a rectangular recess 16 (second recess) is formed in each of the floor wall 13, side wall 14, and ceiling wall 15 (Figure 7). The contaminated surface layer on the periphery of each wall is cut and separated using a wall saw machine 6 (Figure 8). The method for separating the contaminated surface layer on the periphery (hereinafter sometimes referred to as the periphery separation method) will be described in detail later.

The steps described in Figures 2 to 8 will be described in detail below. Figure 9 shows the wall saw machine 3 used in the step of forming the fine grooves 22 described in Figure 2 above. The wall saw machine 3 is equipped with a circular blade 32, a driver 33, a cover 34, and a moving mechanism equipped with a linear guide rail (not shown). The center of the blade 32 is connected to the driver 33 via a shaft 35, and is rotated by the driver 33.

The blade 32 is covered with a cover 34, which is connected to a dust collector 37 via a tube 36. The driver 33 is connected to a moving mechanism equipped with a linear guide rail (not shown). The moving mechanism allows the cover 34, driver 33, and rotating blade 32 to move linearly together along the guide rail, cutting the inner wall and forming the narrow groove 22 in a linear shape. By appropriately changing the positioning of the wall saw machine 3, the narrow groove 22 can be formed in a square ring shape as described in FIG. 2. During the formation of the narrow groove 22 (i.e., while the inner wall is cut by moving the rotating blade 32), the dust collector 37 exhausts and collects dust from inside the cover 34, preventing the scattering of dust generated from the contaminated surface layer.

Note that because the blade 32 is positioned away from the cover 34, when forming the fine grooves 22 near the periphery of the inner wall, the blade 32 is closer to the center of the inner wall than the cover 34. In other words, because the fine grooves 22 are not formed on the periphery of the inner wall, the location where the contaminated surface layer is separated using the wire saw machine 4 is inside the periphery of the inner wall. Therefore, as described with reference to Figure 7, after repeated separation of the contaminated surface layer using the wire saw machine 4, the contaminated surface layer remains on the periphery of the inner wall.

Then, the grooves 22 formed by the wire saw machine 4 are used to form the grooves 23 as described in FIG. 3. The grooves 23 are formed by having an operator peel off the protrusions 24, which are the uncut areas that remain sandwiched between the grooves 22, using a crowbar or the like, so as not to generate dust.

Next, in order to describe the process of separating the contaminated surface layer shown in Figures 4 and 5, the wire saw machine 4 will be described with reference to Figures 10 to 12. Figure 10 is a schematic perspective view of the wire saw machine 4, and Figures 11 and 12 are side views of a guide pulley 51 provided on the wire saw machine 4. Note that the configuration of the wire saw machine 4 in Figure 10 is an example to facilitate understanding of the work process, and the arrangement and number of each pulley other than the guide pulley 51, the shape of the support 41 supporting each pulley, etc. may be changed as appropriate within the scope of possible work.

The wire saw machine 4 includes a support 41 that supports various pulleys and a hydraulic unit (not shown). As described above, the position of the support 41 is changed when cutting the area to be separated 21 in two steps. The support 41 includes a support 42 and two arms 43 that extend in a direction perpendicular to the extension direction of the support 42, and the two arms 43 extend in opposite directions. A base 44 is provided on the lower side of the support 42, and the base 44 can be fixed on the area to be separated 21 via an anchor bolt 45. The support 41 is provided with two guide pulleys (first and second guide pulleys) 51, a number of pulleys 52, a main pulley 53, and a tension pulley 54, and an endless wire saw 55 is stretched across these pulleys. In the example of FIG. 10, the main pulley 53 is provided on the support 42, and each pulley 52 is provided on each arm 43. In addition, a tension pulley 54 is provided on a secondary support 46 that extends from one of the arms 43 in parallel to the support 43, and is movable in the extension direction of the secondary support 46.

The hydraulic unit includes a hydraulic pump and is connected to the support 41 via a tube (not shown). The hydraulic unit rotates the main pulley 53 and moves the tension pulley 54. This rotates the wire saw 55 and applies tension to the wire saw 55 wound around the object to be cut, allowing the object to be cut. During the work described below, the hydraulic unit is placed, for example, outside room 11 in a room where the contaminated surface layer has already been separated.

The two guide pulleys 51 are pulleys that are placed closer to the cutting target than the other pulleys, and are each provided on the arm 43 of the support 41. When the support 41 is placed on the separation target area 21, the guide pulleys 51 can enter the groove 23, and are positioned apart from each other in accordance with the width of the separation target area 21 so as to sandwich the separation target area 21 from the front and rear. When the support 41 is placed in this manner, the shaft 50 (see FIG. 11) of the guide pulley 51 is extended forward and backward. The support 41 is placed on the separation target area 21, but as will be described later in detail, it is placed on the contaminated surface layer when performing the first cut, and is placed in the contaminated surface layer separation area 20 (i.e., in the area where the contaminated surface layer has already been separated) when performing the second cut. Therefore, the height at which the support 41 is placed during each cut is different from each other. In order to accommodate changes in the height at which the support 41 is installed, for example, the attachment position of the guide pulley 51 on the arm 43 can be changed in the length direction of the support 41's pillar 42.

The following description will be given with reference to the process diagrams in Figures 13 to 16. Figures 13 to 16 are also plan views showing in more detail the process of separating the contaminated surface layer by the wire saw machine 4 described in Figures 4 and 5, and therefore show how the contaminated surface layer of the floor wall 13 is separated. Note that in Figures 13 and 15, the wire saw 55 is shown with solid lines and dashed lines, and how the wire saw 55 moves.

First, the support 41 is fixed to the left side of the region to be separated 21 so that the two guide pulleys 51 are positioned in the groove 23, sandwiching the left side of the region to be separated 21 from the front and rear. As described above, when the support 41 is fixed in this manner, the shaft 50 of the guide pulley 51 is in a state of being extended in the front and rear. To further explain the arrangement of the guide pulley 51, the outer circumferential surface of the guide pulley 51 faces the bottom surface of the groove 23. Then, the wire saw 55 is installed so that it crawls along the bottom surface of the groove 23 as shown by the solid line in Figure 13 to surround the right side of the region to be separated 21, and is also hung across the guide pulley 51 and pulled out to the outside of the groove 23 (i.e., facing upward).

Then, the wire saw machine 4 is driven, and the wire saw 55 rotates, while the tension pulley 54 moves upward and away from the region to be separated 21. As a result, tension is applied to the portion of the wire saw 55 that is wrapped around the region to be separated 21, toward the left of the region to be separated 21. Note that Figure 10, already explained, shows the wire saw machine 4 in this state, and Figure 11 shows the guide pulley 51 and wire saw 55 in this state.

The above operation of the wire saw machine 4 cuts the area to be separated 21 along the bottom surface of the groove 23 toward the left side. That is, the first cut of the area to be separated 21 is performed. Then, when the cut surface reaches approximately the center of the left and right of the area to be separated 21, the cutting by the wire saw machine 4 is stopped. The dashed line in FIG. 13 indicates the wire saw 55 at the time when the first cut is stopped. After that, the cut contaminated surface layer is separated into pieces of a size that can be carried out from the room 11, and the right half of the area to be separated 21 becomes the contaminated surface layer separation area 20 (FIG. 14). Note that, due to this separation of the contaminated surface layer, the part of the groove 23 surrounding the right half of the area to be separated 21 disappears. Then, on the right side of the contaminated surface layer of the area to be separated 21 that still remains, a recess 29 (first recess) consisting of the contaminated surface layer separation area 20, which is the right half of the area to be separated 21, and the area that formed the groove 23 as described above, is formed.

Then, the position of the support 41 is changed and fixed on the contaminated surface separation area 20. The guide pulley 51 is located on the bottom surface that formed the groove 23 surrounding the right side of the separation target area 21, and enters the above-mentioned recess 29, with the shaft 50 extended forward and backward. To further describe the arrangement of the guide pulley 51, the outer circumferential surface of the guide pulley 51 faces the bottom surface of the recess 29. Then, the wire saw 55 is installed so that it crawls along the bottom surface of the groove 23 to surround the left side of the separation target area 21 as shown by the solid line in FIG. 15, and is pulled out to the outside of the recess 29 via the guide pulley 51 (i.e., facing upward). Next, the wire saw machine 4 is driven, and the wire saw 55 rotates, and the tension pulley 54 moves upward so as to move away from the separation target area 21. As a result, tension toward the right side of the separation target area 21 is applied to the part of the wire saw 55 that is wrapped around the left side of the separation target area 21. FIG. 12 shows the guide pulley 51 and wire saw 55 in this state, and the region to be separated 21 is cut toward the right along the bottom surface of the groove 23. In other words, the second cut of the region to be separated 21 is performed.

When the wire saw 55 reaches approximately the center of the region to be separated 21 on the left and right sides and all of the contaminated surface layer on the left side has been cut off, the wire saw machine 4 is stopped. The dashed line in Figure 15 shows the wire saw 55 when the second cut is stopped. After this second cut, the contaminated surface layer on the left side is separated into pieces large enough to be carried out of the room 11, just like the contaminated surface layer on the right side of the region to be separated 21, and the entire region to be separated 21 becomes the contaminated surface layer separation region 20 (Figure 16). For ease of explanation, the method of cutting and separating the region to be separated 21 in two steps using the wire saw machine 4 described in Figures 13 to 16 may be referred to as the split separation method.

As described in FIG. 6, the formation of the groove 23 and the division and separation method are repeated. This expands the contaminated surface layer separation area 20 in the floor wall 13. In addition, the groove 23 formed along the separation target area 21 in the floor wall 13 to perform the second and subsequent division and separation methods may be U-shaped in plan view as shown in FIG. 6, and both ends of the groove 23 may be connected to the already formed contaminated surface layer separation area 20. In other words, it does not need to be annular like the groove 23 formed to perform the first division and separation method, and therefore the narrow groove 22 for forming the groove 23 may also be U-shaped in plan view. In this way, when performing the second and subsequent division and separation methods, the recess that forms the contaminated surface layer separation area 20 and the U-shaped groove 23 correspond to the first groove surrounding the separation target area 21.

Then, after the contaminated surface layer of the floor wall 13 is separated leaving the peripheral edge (i.e., after the recess 16 shown in FIG. 7 is formed), the contaminated surface layer of the side wall 14 and the ceiling wall 15 is also separated in the same manner as the floor wall 13, as described above. When placing the wire saw 55 in the groove 23 formed in the ceiling wall 15 to perform the division separation method on the ceiling wall 15, a drop prevention member 26 for the wire saw 55 is provided in the region to be separated 21, as shown in the bottom view of FIG. 16, for example. This drop prevention member 26 is fixed to the region to be separated 21 with a bolt or the like, and supports the wire saw 55 from below by protruding outward from the region to be separated 21 and overlapping part of the groove 23.

The edge separation method described in Figures 7 and 8 will now be described with reference to the process diagrams of Figures 18 to 20 and the vertical cross-sectional views of the corners of room 11 in Figures 21 and 22. Figures 18 to 20 are also schematic perspective views of the interior of room 11. Figure 18 shows the state before the edge separation method is performed, with the aforementioned recesses 16 formed in each inner wall. From the state shown in Figure 18, the contaminated surface layer is separated using a wall saw machine 6. As shown in Figures 21 and 22, the wall saw machine 6 is different from the wall saw machine 3 in that it does not have a cover 34.

The wall saw machine 6 cuts the side of the bottom of the recess 16 toward the outside of the recess 16 with the blade 32 in close proximity to and facing the bottom of the recess 16. Then, the blade 32 is moved linearly along the periphery of the inner wall while still facing the bottom of the recess 16, forming a groove 61 (second groove) (Figure 19). In other words, the depth direction of the groove 61 is from within each recess 16 toward the outside of the recess 16, and the groove 61 is formed around the entire circumference of the recess 16.

The above-mentioned grooves 61 are formed for each recess 16. In Fig. 19, the grooves 61 are shown to be formed all at once in order to show the positions where the grooves 61 are formed, but in reality they are formed in sequence. Figs. 21 and 22 show an example in which the grooves 61 are formed in the floor wall 13 and the side wall 14 in that order. Since the bottom of the recess 16 is cut, the contaminated surface layer is prevented from turning into dust when the grooves 61 are formed.

To further explain each groove 61, each groove 61 is formed to have a depth that allows the grooves 61 formed in adjacent inner walls of the floor wall 13, side wall 14, and ceiling wall 15 to be connected to each other. In other words, the grooves 61 formed in the floor wall 13 and the grooves 61 formed in each of the four side walls 14 are connected to each other, the grooves 61 formed in adjacent side walls 14 of the four side walls 14 are connected to each other, and the grooves 61 formed in the ceiling wall 15 and the grooves 61 formed in each of the four side walls 14 are connected to each other. The arrows in Figure 19 and Figure 22 show the grooves 61 formed in the recesses 16 of the floor wall 13 and the grooves 61 formed in the recesses 16 of the side walls 14 connected to each other.

As already mentioned, the grooves 61 formed on each inner wall are connected, and the contaminated surface layer of room 11 is separated from room 11 as a rectangular frame as shown in FIG. 20. For ease of understanding, FIG. 20 shows the rectangular frame as it is separated from room 11, but in reality it is cut into a size that can be carried out of the room, and then separated. This completes the separation of the contaminated surface layer within room 11 as shown in FIG. 8.

Now, a comparative example to the dividing and separating method described in Figures 13 to 16 will be described with reference to the plan view of Figure 23 and the side view of Figure 24. In this comparative example, the region to be separated 21 is cut using a wire saw machine in which a guide pulley 51 is arranged so that the shaft 50 extends in the thickness direction of the region to be separated 21. In this comparative example, the region to be separated 21 is set adjacent to a region 71 from which the contaminated surface layer has already been separated, and the groove 23 in which the wire saw 55 is installed is U-shaped in plan view and its end is connected to the region 71. In the figure, 70 is a device equivalent to the support 41 of the wire saw machine 4, and includes various pulleys other than the guide pulley 51.

If the area to be separated 21 is cut near its surface, the area to be separated 21 will break into dust and fly away. For this reason, it is desirable to position the wire saw 55 on the bottom surface of the groove 23 and cut the surface of the area to be separated 21 along the bottom surface so that the surface layer of the area to be separated 21 to be cut is sufficiently thick, for example about 5 cm. On the other hand, the guide pulley 51 is recessed in the center in the thickness direction, and the wire saw 55 is placed in the recess. In other words, considering the position of the guide pulley 51 where the wire saw 55 is placed and the position of the wire saw 55 on the bottom surface of the groove 23, a recess 72 is formed by cutting the area 71 as shown in FIG. 24, and the guide pulley 51 is embedded in the recess 72.

However, forming the recess 72 in this manner is time-consuming. Also, securing space for the guide pulley 51 and the equipment 70 in the area 71 where contamination has been separated, as in this comparative example, may cause delays in the work. Therefore, as described in the above embodiment of the present invention, it is desirable to arrange the guide pulley 51 so that the shaft 50 extends forward and backward, and to arrange the area to be separated 21 between the front and rear, so that the wire saw 55 drawn over the bottom surface of the groove 23 can be hung. However, when arranging the guide pulley 51 in this manner, it is time-consuming to widen the groove 23 so that the direction of the guide pulley 51 can be changed depending on the position of the wire saw 55, as described in the explanation of Patent Document 1.

Therefore, in this embodiment, as described above, the left and right sides of the region to be separated 21 are cut in order, and the position of the support 41 equipped with the guide pulley 51 is changed when changing the side to be cut. Therefore, while cutting of the contaminated surface layer is in progress, the guide pulley 51 can be positioned at a position relatively far away from the center of the left and right sides of the region to be separated 21 where cutting is to be stopped. In other words, even as cutting progresses, the wire saw 55 is kept extended in the left and right direction near the guide pulley 51, so the orientation of the guide pulley 51 does not need to be changed. Therefore, there is no need to widen the groove 23 to secure the space required to change the orientation of the guide pulley 51.

As described above, according to this embodiment, when cutting and separating the contaminated surface layer, the wire saw 55 moves along the bottom surface of the groove 23, and the guide pulley 51 is positioned so that the contaminated surface layer is cut with a sufficient thickness and is not crushed. Furthermore, the burden required for installing the guide pulley 51 is small. In other words, this embodiment prevents the contaminated surface layer from turning into dust and scattering, and prevents an increase in the amount of work required. In this embodiment, when placing the support 41 in the separation target area 21 or changing its position as described above, it is sufficient to form a hole through which the anchor bolt 45 for fixing the base 44 of the support 41 passes, and to attach and detach the anchor bolt 45. Therefore, the work is simpler than forming a recess 72 for the guide pulley 51 as in the comparative example.

Although it has been stated that there is no need to widen the groove 23 or change the orientation of the guide pulley 51, the present invention does not prohibit such widening or changing the orientation of the guide pulley 51. Even if the orientation of the guide pulley 51 is changed, the present invention limits the amount of change in the orientation that is required, so that the amount of widening of the groove width is small, and the labor required for the work can be reduced.

In addition, in the above-mentioned division and separation method, different wire saw machines may be used for the first cut shown in FIG. 13 and the second cut shown in FIG. 15. For example, the above-mentioned wire saw machine 4 is used for the first cut. Then, a wire saw machine with a smaller distance between the guide pulleys 51 than the wire saw machine 4 is used for the second cut. Then, each guide pulley 51 of the wire saw machine is arranged so as to overlap with the right contaminated surface layer separation area 20 in the recess 29, and the wire saw 55 hung on the left side of the separation target area 21 is hung on the guide pulley 51 and arranged so as to face upward from the contaminated surface layer separation area 20 to perform cutting. In other words, the guide pulley 51 during the second cut is not limited to being installed at the location where the groove 23 was provided. In the above embodiment, the axes 50 of the two guide pulleys 51 are shown as being parallel to the width direction of the separation target area 21 in a plan view, but may be slightly inclined. That is, the two guide pulleys 51 may be arranged so that each shaft 50 forms a V shape in a plan view.

The wall saw machine 3 for forming the narrow grooves 22 may have a two-blade structure. More specifically, for example, a wall saw machine 3 having two circular blades 32 of the same size that face each other and are close to each other, and in which the two blades 32 are rotated together by a drive 33, may be used to simultaneously form two parallel narrow grooves 22. Both blades 32 are covered by a cover 34, and as described above, the inside of the cover 34 is evacuated and dust is collected to prevent dust from scattering.

As described in Figs. 13 to 16, the contaminated surface layer of the separation target area 21 of the floor wall 13 is separated to form the contaminated surface layer separation area 20 by performing the division separation method, and then, after forming a U-shaped groove 23 to surround the newly determined separation target area 21 as shown in Fig. 6, the support 41 of the wire saw machine 4 may be fixed to the already formed contaminated surface layer separation area 20 instead of being placed on the separation target area 21. Then, the contaminated surface layer of the separation target area 21 surrounded by the groove 23 may be cut at once. After performing the division separation method once on the floor wall 13 in this way, the separation of the contaminated surface layer may be progressed without using the division separation method. As with the floor wall 13, the division separation method may be performed only once on each of the side wall 14 and the ceiling wall 15.

When performing the division and separation method, the area to be cut the first time and the area to be cut the second time are divided in the length direction of the area to be separated 21, but they may also be divided in the width direction (short direction) of the area to be separated 21. In other words, either the upper side or the lower side in the plan views of Figures 13 to 16 may be cut the first time, and the other may be cut the second time. In addition, when performing the division and separation method, the area of the area to be cut the first time and the area of the area to be cut the second time do not necessarily have to be the same, and there may be a bias. Note that a groove 23 is formed as a first groove so as to surround the periphery of the area to be separated 21, but for example, a wide recess is formed around the area to be separated 21 using heavy machinery or the like. Such a wide recess is also the first groove.

This technology can be applied to any surface layer of a concrete structure, and is not limited to being used for separating the surface layer of the inner wall of the room 11 described above, and may be used to separate, for example, the surface layer of an outer wall of a concrete structure. The area 21 to be separated is not limited to being rectangular, and may be, for example, circular, in which case the groove 23 may be formed in an annular shape using appropriate equipment and tools in accordance with the shape of the area 21 to be separated.
Incidentally, among the inner walls of the room 11, only the floor wall 13 and each side wall 14 may be separated from the room 11 by forming a recess 16 by separating the contaminated surface layer as described in Figs. 1 to 6, and forming a groove 61 of the depth described above in each recess 16, and separating the periphery of the floor wall 13 and each side wall 14 from the room 11. In this separation, it is necessary to separate the periphery of each side wall 14 from the ceiling wall 15. This separation is performed, for example, by applying the blade 32 of the wall saw machine 3 described above to the corners between each side wall 14 and the ceiling wall 15 or the vicinity thereof, and moving the blade 32 along the periphery of the ceiling wall 15 while exhausting and collecting dust from the inside of the cover 34. Since the portion to be cut by the wall saw machine 3 is a contaminated surface layer, cutting is performed while exhausting and collecting dust in this manner.
Similarly, only the ceiling wall 15 and each side wall 14 may be separated from the room 11 by forming a recess 16 by separating the contaminated surface layer as shown in Figures 1 to 6, and forming a groove 61 of the depth described above in the recess 16. During this separation, it is necessary to separate the peripheral edges of each side wall 14 from the floor wall 13. For this separation, the wall saw machine 3 is used to cut the corners between the side walls 14 and the floor wall 13 or their vicinity, in the same manner as in the above-mentioned separation of the peripheral edges of each side wall 14 from the ceiling wall 15, and exhaust and dust collection may be performed inside the cover 34 during the cutting.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above embodiments may be omitted, substituted, modified, combined, etc. in various forms without departing from the scope and spirit of the appended claims.

10 Building 13 Floor wall 23 Groove 21 Separation target area 29 Recess 51 Guide pulley 55 Wire saw

Claims (5)

A method for separating a surface layer of a concrete structure using an endless wire saw, comprising:
a groove forming step of cutting a periphery of a region to be separated that forms the surface layer to form a first groove surrounding the region to be separated;
a first installation step of installing first and second guide pulleys in the first groove so as to sandwich a surface layer on one of the left and right sides of the region to be separated from the front and rear and so that an outer circumferential surface of the first guide pulley faces a bottom surface of the first groove;
a first cutting step of cutting and separating the surface layer by using the wire saw so as to be wound around the surface layer on the other side of the region to be separated, and to be stretched across the first and second guide pulleys and pulled out to the outside of the first groove;
a second installation step of installing the first and second guide pulleys in a first recess formed by separating the surface layer in the first cutting step such that an outer circumferential surface of the first and second guide pulleys faces a bottom surface of the first recess;
a second cutting step of cutting and separating the surface layer by using the wire saw so as to be wound around the surface layer on one of the left and right sides of the region to be separated and to be stretched across the first and second guide pulleys and drawn out to the outside of the first recess;
Equipped with
the separation target region is a surface layer of the adjacent inner walls, which are the floor wall and the side wall or the ceiling wall and the side wall, among the floor wall, the side wall, and the ceiling wall, which are the inner walls of a room;
the groove forming step includes a step of forming the first groove on the inner side of a periphery of each of the adjacent inner walls,
a step of repeatedly performing the groove forming step, the first setting step, the first cutting step, the second setting step, and the second cutting step to form a second recess in each of the adjacent inner walls;
a separation process of forming second grooves extending from within each of the second recesses toward the outside of the second recesses along the periphery of each of the adjacent inner walls and connecting the second grooves formed in each of the adjacent inner walls to each other, and separating the periphery of the surface layer of the adjacent inner walls from the concrete structure;
A method for surface layer separation of a concrete structure comprising : the separation target area is a surface layer of each of the floor wall, the side wall, and the ceiling wall,
the groove forming step includes a step of forming the first groove on the inner side of a periphery of each of the floor wall, the side wall, and the ceiling wall,
the step of forming the second recess is a step of forming the second recess in each of the floor wall, the side wall and the ceiling wall,
2. The surface layer separation method for a concrete structure according to claim 1, wherein the separation process is a process of forming the second grooves in adjacent inner walls of the floor wall, the side wall and the ceiling wall so that the second grooves are connected to each other, and separating each surface layer of the floor wall, the side wall and the ceiling wall from the concrete structure. The step of forming the first groove includes a step of forming a groove by a wall saw machine including a circular first blade and a cover covering the first blade;
The step of forming the groove includes a cutting step of cutting the periphery of the region to be separated by moving the cover and the rotating first blade together;
a step of exhausting air from within the cover and collecting dust during the cutting step;
3. The method for surface layer separation of a concrete structure according to claim 1 or 2, comprising: In the first installation step, the first and second guide pulleys are installed in the first groove such that rotation axes of the first and second guide pulleys extend in the front-rear direction;
4. The surface separation method for a concrete structure according to claim 1, wherein in the second installation step, the first and second guide pulleys are installed in the first recess so that the rotation axes of the first and second guide pulleys extend forward and backward. The first installation step includes a step of fixing a support for supporting the first and second guide pulleys, a main pulley around which the wire saw is stretched and which rotates to rotate the wire saw, and a tension pulley around which the wire saw is stretched and which moves so as to apply the tension to the wire saw, to the surface layer on one of the left and right sides of the region to be separated;
5. The surface layer separation method for a concrete structure according to claim 1, wherein the second installation step includes a step of fixing the support to an area where the surface layer has been separated in the first cutting step.

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