JP2017008718A - Crack repair method for underwater part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crack repair method for an underwater part, which can prevent a filler from leaking by installing a simple formwork and easily grasp a filling state of the filler by visual inspection under water.SOLUTION: A crack repair method for an underwater part is a method to repair a crack on an underwater part of a concrete structure. A light permeable sheet material 11 made of elastic material is fixed on a surface S of an underwater part C having a crack CR so as to cover the crack. A filler is charged in the crack by injecting an underwater antiwashout plastic grout material as a filler 21 through injection parts 12a, 12c formed on the surface of the sheet material. Filling state of the filler is checked through the light permeable sheet material.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for repairing a crack in an underwater part of a concrete structure.

  In various concrete structures such as revetments, quay walls, and dams, defects such as cracks may occur in the underwater part that comes into contact with water during operation. A conventional repair method for cracks in concrete in the underwater part will be described with reference to FIG. As shown on the left side of FIG. 7, in the case of a crack CR generated in the underwater part C of the concrete structure, the injection hole 52 is drilled from the ground toward the crack CR in the underwater part C, and then the injection plug 52, The filler material was injected by a plunger pump or the like through the injection hole 51, and the putty seal 53 was applied to the crack surface of the underwater part C. In the case of a crack CR ′ as shown on the right side of FIG. 4, the injection hole 56 is drilled from the ground toward the crack CR ′ in the underwater part C, and the surface of the underwater part C is covered with the crack CR ′. The mold 55 such as the above was attached, a drain pipe 57 was provided in the mold 55, the periphery of the mold 55 was stopped with a putty seal 55a, and then the grout material was filled into the crack CR 'through the injection hole 56. .

  Patent Document 1 discloses a case in which a casing portion provided at a distal end portion of a filling material injection path for injecting and filling cement milk into a water leakage location in water includes an injection port for injecting cement milk into the water leakage location, and the injection port. A view window provided so that the inside of the housing can be seen from the outside, and an open / close valve that allows the inside and outside of the housing to communicate and shut off, and injects cement milk from the inlet into the water leakage location. When filling, the amount of cement milk that has been injected at the relevant water leakage point is injected while checking the state of injection through the image taken by the underwater camera through the viewing window provided in the housing. Disclosed is an underwater injection device that can be filled, and a filling material injection monitoring method using the same.

  Patent Document 2 discloses a composition for underwater construction and a seal material filling part by installing a mold so as to maintain a distance of 5 to 30 mm from the surface of an existing structure, and at least a part of the repair part. And an underwater construction method for filling at least part of the sealing material filling portion with the composition for underwater construction.

  Patent Document 3 discloses that cracks penetrating through the front and back of a concrete frame are provided with a suction portion on the inner side and a filler supply portion on the outer side, thereby sucking air in the crack space from the inner side and causing cracks. A method and apparatus for repairing a concrete crack in which the air pressure in the space is reduced and the filler material is sucked into the crack space by such a negative pressure to fill the filler material in the crack space is disclosed.

JP-A-10-102494 JP-A-2015-224291 Japanese Unexamined Patent Publication No. 09-209577

  The drilling of the injection holes 51 and 56 from the ground in FIG. 7 is possible up to a water depth of about -1 m. However, when the water depth of the repaired part becomes deep, the construction of the injection hole from the ground becomes difficult. there were. In addition, the injection of filler material for repairing cracks on land has covered the entire crack with a putty to prevent the injection material from flowing out, while underwater construction also covered the crack with the putty. Although possible, there is a problem that work is poor because the work is performed by a diver, and the construction takes time.

  Even when a mold is installed, there is a demand for a repair method that is as simple as possible in water, such as the weight of the mold and the fixing method. Further, when a non-plastic grout material is used for filling a crack in water, it is necessary to completely stop the mold and the periphery of the crack with a putty or the like in order to prevent leakage of the filling material. On the other hand, as a repairing method in the underwater part, a method of applying the vicinity of the surface with a hardened epoxy mortar may be used. In this case, the repair is limited to the vicinity of the surface of the structure, and it is difficult to fill the repair material into the member.

  In the filling material injection monitoring method of Patent Document 1, in order to check the injection state of the filling material in water, the cement milk injection port is imaged by an underwater camera through a viewing window that is visually recognized from the outside of the housing part. Although the injection state is confirmed by the video, a large-scale image system using an underwater camera and an image display device is required.

  In the underwater construction method of Patent Document 2, the formwork must be installed so as to maintain a distance of 5 to 30 mm from the surface of the existing structure, and the weight and fixing method of the formwork become problems. The repair method of Cited Document 3 is for cracks penetrating the front and back of a concrete concrete body on land, and cannot be applied to underwater parts or cracks not penetrating.

  In view of the problems of the prior art as described above, the present invention can prevent the leakage of the filling material by installing a simple formwork in the water, and repair the cracks in the underwater part that can easily grasp the filling state of the filling material visually. It aims to provide a method.

  An underwater crack repairing method for achieving the above object is a method for repairing a crack in an underwater part of a concrete structure, in which a light-transmitting sheet material made of an elastic material is applied to an underwater part with a crack. The surface is fixed so as to cover the cracks, and the filler material is filled in the cracks by injecting an underwater non-separable plastic grout material as a filling material through an injection part formed on the surface of the sheet material. The filling state of the filling material is confirmed through the light-transmitting sheet material.

  According to this method for repairing cracks in the underwater part, a light-permeable sheet material made of an elastic material is fixed to the surface of the underwater part to cover the cracks. A heavy formwork such as wooden is unnecessary, and the filling material filled through the light-transmitting sheet material can be visually confirmed, and the filling state can be confirmed. Further, since the underwater inseparable plastic grout material is used as the filling material, it is possible to prevent the filling material from leaking from between the surface of the underwater portion and the sheet material as in the case of a conventional nonplastic grout material.

  In the method for repairing a crack in the underwater part, it is preferable to provide at least two injection parts. The filling material can be injected from one injection part, and the other injection part can be changed and filled in the course of injection according to the filling state of the filling material. Moreover, since the injection | pouring part which is not used for injection | pouring of a filling material can drain easily from the inside of a crack through the injection | pouring part, it functions as a drainage part. Further, by providing three or more injection parts, the position of the injection part can be changed in multiple stages. The plurality of injection portions are preferably formed in accordance with the shape, length, and direction of cracks existing on the surface of the underwater portion.

  Further, the injection portion can be formed by making a cut in the sheet material. The shape of the cut is preferably a cross shape.

  Moreover, it is preferable that the thickness of the said sheet material is 1 mm or more and 2 mm or less. The rigidity of the sheet material can be ensured by being 1 mm or more, and the workability and workability can be ensured by being 2 mm or less.

  Moreover, it is preferable to inject | pour the said filling material into the said injection | pouring part through the front-end | tip part of a hand gun.

  According to the method for repairing a crack in an underwater part of the present invention, leakage of the filling material can be prevented by installing a simple mold in water, and the filling state of the filling material can be easily grasped visually.

It is a figure for demonstrating the crack repair method of the underwater part by this embodiment, the front view which shows the surface of the underwater part in which a crack exists (a), The front view which shows the sheet | seat material arrange | positioned on the surface of the underwater part (b) ) And a longitudinal sectional view (c) showing cracks in the underwater portion where the sheet material is arranged. It is a flowchart for demonstrating each process S01-S09 of the crack repair method of the underwater part by this embodiment. FIG. 2 is a partial cross-sectional view schematically showing a state in which a tip of a hand gun is inserted for injection of a filling material into a cross-shaped cut of the light transmissive elastic sheet material of FIG. 1. It is sectional drawing similar to FIG.1 (c) which shows the filling step (a) (b) of the filling material to the crack of the underwater part of FIG. 1 schematically. It is a front view which shows the schematic mode which looked at the filling material with which the crack of the underwater part of FIG. 1 was filled through the light-transmitting elastic sheet material from the front. It is a front view which shows another example of the elastic sheet material of FIG.1 (b). It is a figure for demonstrating the crack repair method of the conventional underwater part.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a method for repairing a crack in an underwater portion according to the present embodiment. FIG. 1A is a front view showing the surface of the underwater portion where a crack exists, and FIG. 1B is a front view showing a sheet material arranged on the surface of the underwater portion. It is a longitudinal cross-sectional view (c) which shows the crack of the underwater part by which the figure (b) and the sheet | seat material are arrange | positioned.

  As shown in FIG. 1 (a), when there is an open crack CR on the surface S of the underwater part C that contacts the water of the concrete structure, the surface S of the underwater part C as shown in FIGS. 1 (b) and 1 (c). The light-transmitting elastic sheet material 11 is fixed using a plurality of fixing means such as concrete nails. The elastic sheet material 11 is configured to have a size so as to cover the crack CR appearing on the surface S of the underwater portion C in FIG.

  The light-transmitting elastic sheet material 11 is formed with a plurality of cross-shaped cuts 12a to 12f. The cuts 12a to 12f can be formed on the surface of the elastic sheet material 11 by simple cutting with, for example, a cutter knife. The plurality of cuts 12a to 12f function as an injection portion when the filling material is injected, and also function as a drainage portion when water in the crack CR is discharged during injection.

  The plurality of cuts 12a to 12f are formed according to the shape, length, and direction of the crack CR existing on the surface S of the underwater portion C. For example, as shown in FIG. 1 (a), when the crack CR exists substantially in a straight line in the vertical direction, the cross-shaped centers of the plurality of cuts 12a to 12f are in the vertical direction as shown in FIG. 1 (b). The lowermost cut line 12a is formed near the lower end of the crack CR, and the uppermost cut line 12f is formed near the upper end of the crack CR. In addition, the plurality of cuts are formed in accordance with the inclination when the crack is inclined with respect to the vertical direction, and are formed in accordance with the bending when the crack is bent in the middle.

  Moreover, as the light-transmitting elastic sheet material 11, for example, a translucent silicon rubber sheet can be used. The thickness of the elastic sheet material 11 is preferably 1 mm to 2 mm.

  Also, a plastic grout material that is inseparable in water is used as a filling material for filling the cracks. The plastic grout material has fluidity at the stage where pressure is applied, but has the property of losing fluidity when pressure is lost. Since the plastic grout material loses pressure and loses fluidity in gaps such as molds, it does not flow out of gaps and is suitable for use in this embodiment. As this non-separable plastic grout material, for example, bentonite is swollen with water, and it is kneaded with water, cement, sand, and an underwater non-separable mortar using an admixture such as an underwater inseparator or water reducing agent. The plastic grout obtained by this can be used.

  In addition, as a plastic grout material that is inseparable in water, a plasticizer is added to air mortar using a special foaming agent, the air mortar is instantly consolidated, and air is sealed in the grout. There is a plastic cavity filling material obtained by the two-component injection method. Such a construction method is known as an air-pack construction method (registered trademark) (refer to pamphlet “air-pack construction method” plastic grout association issued in October 2007, Japanese Patent No. 3618275).

  Furthermore, as the plastic grout material that is inseparable in water, the main material cement contained in the cement milk material is low heat Portland cement, and the fly ash contained in the cement milk material is a high quality fly ash equivalent to JIS standard type II. There is a plastic grout material in which the modified fly ash is a non-separable admixture in water contained in a cement milk material and an acrylamide-2-methylpropanesulfonic acid-based thickener (Japanese Patent Laid-Open No. 2016-175803) reference).

  In this embodiment, when the width W of the crack CR existing in the underwater portion C and opening to the surface S thereof is about 1 mm to 10 mm, the crack is targeted for repair, but this lower limit is 1 mm underwater. This is set because it is difficult to detect small cracks with a width of less than 1 mm, and it does not mean that if cracks with a width of less than 1 mm are detected, they will not be repaired uniformly. The upper limit value is set because the crack width is normally about 10 mm at the maximum, and cracks with a width exceeding the upper limit value can be repaired.

  The underwater part crack repairing method according to the present embodiment will be described with reference to FIGS. FIG. 2 is a flowchart for explaining the steps S01 to S09 of the underwater crack repair method according to this embodiment. FIG. 3 is a partial cross-sectional view schematically showing a state in which a tip of a hand gun is inserted for injection of a filling material into a cross-shaped cut of the light-transmitting elastic sheet material of FIG. FIG. 4 is a cross-sectional view similar to FIG. 1C schematically showing the filling steps (a) and (b) of the filling material into the cracks in the underwater portion of FIG. FIG. 5 is a front view showing a schematic view of the filling material filled in the cracks in the underwater portion of FIG. 1 as seen from the front through a light-transmitting elastic sheet material.

  This will be described with reference to FIG. First, a diver or the like visually inspects the underwater part of the concrete structure (S01), and a crack CR is detected on the surface S of the underwater part C as shown in FIG. 1 (a) (S02), and this crack CR is repaired. If the target is determined, the repair process is executed by a diver or the like as follows.

  As shown in FIG. 1B, a light-transmitting elastic sheet material 11 such as silicon rubber having a size covering the crack CR on the surface S of the underwater part C is prepared. It is fixed to the surface S with concrete nails 13 or the like (S03). The elastic sheet material 11 is formed with a plurality of cross-shaped cuts 12a to 12e.

  Next, as shown in FIG. 3, the above-mentioned filling material is filled in a hand gun type injector 20, and a tip portion 20c formed in a knife shape at the tip of a small diameter pipe 20b provided on the injection side of the injector 20 is used. Is inserted into the cross-shaped cut 12a formed at the bottom of the elastic sheet material 11 in FIG. 1B, and the injector 20 is set (S04).

  Next, by pushing the pushing portion 20a provided on the rear end side of the injector 20 toward the front end side, the filling material inside the injector 20 is sent out, and as shown in FIG. 4A, the crack CR is filled. Material 21 is injected (S05).

  The filling material injection step S05 described above fills the filling material 21 from the lower part of the crack CR as shown in FIG. 4 (a). During the process, it is determined whether or not to continue the injection (S06). Such determination can be easily made by visually checking the filling state of the filling material 21 in the cracked CR through the light-transmitting elastic sheet material 11 as shown in FIG.

  Further, by filling the cracking CR with the filling material 21 as shown in FIG. 4A, the water in the cracking CR is discharged to the outside through the other cuts 12b to 12e.

  For example, as shown in FIG. 4A, when it is determined that the filling material 21 has been filled up to the height at which the injector 20 is set (the height of the cut 12a), the filling material injection is interrupted (S06), Next, it is determined whether or not to change the injection position (S07). The determination of the injection position change can be easily performed by visually checking the filling state of the filling material 21 in the crack CR through the light-transmitting elastic sheet material 11 as shown in FIG.

  When it is determined that the injection position is to be changed (S07), the injector 20 is pulled out from the cut 12a of the elastic sheet material 11, and the process returns to the above step S04, and the injector 20 is set in the cut above the cut 12a, for example, the cut 12c. The filling material is injected in the same manner as in step S05. By such injection, the filling material 21 is continuously filled in the crack CR as shown in FIG.

  By repeating the above steps S04 to S07, the filling material 21 is filled into the crack CR. By visually confirming the filling state of the filling material 21 in the crack CR through the light-transmitting elastic sheet material 11, the filling material 21 is filled. When it is determined that the material is completely filled in the crack CR, the filling material injection is completed (S08). Next, the removal of the elastic sheet material 11 and the post-treatment of the surface S filled with the filling material are performed as necessary (S09).

  As described above, according to the underwater portion crack repairing method according to the present embodiment, the light-transmitting elastic sheet material 11 such as translucent silicon rubber is fixed to the surface S of the underwater portion C to cover the crack CR. By fixing with concrete nails 13 etc., a simple formwork can be installed in the underwater part and filling material can be filled, so there is no need for conventional heavyweight formwork such as wooden formwork or covering with putty, Since the filling material filled in the crack CR can be visually confirmed through the light-transmitting elastic sheet material 11, the filling state of the filling material can be easily confirmed.

  Further, according to the experiment by the present inventor, when a non-plastic grout material is used as the filling material, the filling material leaks from between the elastic sheet material and the concrete surface of the underwater portion, and filling is impossible. On the other hand, it was confirmed that the filling material can be prevented from leaking from between the surface of the underwater portion and the elastic sheet material by using a water-inseparable plastic grout material as the filling material. The underwater separable plastic grout material is suitable for filling cracks in the underwater part because it is resistant to water and plastic.

  The filling material can be injected easily by cutting through the slit formed in the elastic sheet material 11 with a cutter or the like. Further, according to the experiment of the present inventor, when the width w of the crack CR in FIG. 1 (a) is 5 mm, filling was possible with a cross-shaped cut having a width of 2 cm and a height of 2 cm. In addition, when the thickness of the elastic sheet material is 3 mm or more, it becomes difficult to pass the tip 20c of the injector 20 through the cut, and the workability and workability in water deteriorate, whereas the thickness of the elastic sheet material decreases from 1mm to According to the 2 mm elastic sheet material, the tip 20c of the injector 20 can be passed through the cut relatively easily by a diver in water.

  That is, as shown in FIG. 3, when the tip 20c of the injector 20 is to be inserted into the cut 12a of the elastic sheet material 11, the periphery of the cut 12a is elastically deformed relatively easily, and the tip 20c is easily formed. Can pass through. This facilitates diver work in water, so the thickness of the elastic sheet material is preferably 2 mm or less. Further, if the thickness of the elastic sheet material is less than 1 mm, the rigidity is lowered and the holding effect of the filling material is lowered, so that the thickness is preferably 1 mm or more. In addition, when the cut is formed by a cutter or the like, there is an effect of preventing the leakage of the filling material at the cut that is not involved in the filling when the filling material is injected.

  Moreover, although water exists inside the crack of the underwater part, as shown in FIG. 1B, by providing a plurality of cuts 12a to 12e in the elastic sheet material 11, cuts that are not used for filling material filling are drained. It functions as a part and drains easily from the crack CR through such a cut. For this reason, the filling material can be injected by the injector 20 at a relatively small pressure. In the construction using the drain pipe 57 provided in the mold 55 as shown in FIG. 7, the pressure for draining water is high, so that it is necessary to increase the pressure when the filling material is injected.

  In addition, since the elastic sheet material 11 is provided with a plurality of cuts 12a to 12e, the filling material is injected from the lower cut, and when the injection is completed to some extent, the injection position is changed to the upper cut. Can do. At this time, since the filling state of the filling material filled in the crack CR through the light-transmitting elastic sheet material 11 is known, the injection position can be changed with good timing while observing the filling state.

  Further, in FIG. 1B, a plurality of (three or more) cuts are provided in the elastic sheet material 11, but the invention is not limited to this. For example, the cuts may be provided at two places above and below. That is, as shown in FIG. 6, cuts 11f are formed above and below the light-transmitting elastic sheet material 11A such as translucent silicon rubber in accordance with, for example, the vicinity of the lower portion and the upper portion of the crack CR in FIG. 11g. The cuts 11f and 11g function as an injection part at the lower side and as a drainage part at the upper side, respectively. The elastic sheet material 11 </ b> A is fixed to the surface S of the underwater part C using a plurality of concrete nails 13 as in FIG. 1C, and has the same effect as the elastic sheet material 11 described above.

[Experimental result]
Silicon rubber sheet (thickness 1, 3, 5 mm, both translucent) as an experimental example and chlorobrene rubber (thickness 1, 3, 5 mm) as a comparative example, and cracking in water using a caulking gun Filling material injection experiments were performed. As a result, translucent silicon rubber sheet (1mm thick) was the best result for filling cracks in water. Silicon rubber sheets are translucent and the filling status can be checked visually, while black rubber sheets (chlorobrene rubber) do not know the filling status, and the filling material is excessively filled, and the filling material leaks out. It was easy to do. In addition, the rubber sheets with thicknesses of 3 mm and 5 mm had a large repulsive force, and it was difficult to pass the tip of the caulking gun through the sheet. With a 1 mm thick silicon rubber sheet, the filling material does not leak from the cuts provided in the sheet, the filling material can be injected from any cut, and the filling height is visible because it is translucent. there were.

  As described above, the modes for carrying out the present invention have been described. However, the present invention is not limited to these, and various modifications can be made within the scope of the technical idea of the present invention. For example, the shape of the cut formed in the elastic sheet material 11 is preferably a cross shape composed of two lines, but is not limited to this in the present invention. For example, a horizontal line “-” or a vertical line “ | "Or diagonal line shape" / ", or a triple line shape where three lines intersect at the center.

  Further, as the light-transmitting elastic sheet material, a translucent silicon rubber sheet is used in the present embodiment and experimental examples, but the present invention is not limited to this. For example, transparent or translucent vinyl chloride or urethane is used. A rubber sheet or the like may be used. Further, the elastic sheet material needs to be light transmissive, but it is sufficient if the filling state of the filling material in the crack is visible in water.

  In addition, concrete structures to which the repair method according to the present invention is applied include revetments, quay walls, and dams, but are not limited thereto, and at least a part of the concrete structure has an underwater part in contact with water. Applicable.

  Conventionally, with regard to repairing cracks in the underwater part of concrete structures such as revetments, quay walls, dams, etc., since it is a work and construction work underwater by a diver, the simplest possible repair method is desired. According to the crack repair method, leakage of the filling material can be prevented by installing a simple formwork such as an elastic sheet material in the water, and the filling state of the filling material can be easily grasped visually, so the water depth is deep. Even in this case, it is possible to provide a repair method that is easy to construct, and a large-scale image system or the like is unnecessary, and the filling status can be confirmed.

11, 11A Light-transmissive elastic sheet material 12a-12e cut (injection part)
13 Concrete nail 20 Injector 20c Tip portion 21 Filling material 12f, 12g Cut C Underwater part S Surface CR Crack W Width of crack

Claims (5)

A method of repairing a crack in the underwater part of a concrete structure,
A light-transmitting sheet material made of an elastic material is fixed so as to cover the cracks on the surface of the cracked underwater part,
Filling the cracking material with the filling material by injecting a plastic grout material that is inseparable in water as a filling material through an injection part formed on the surface of the sheet material,
A method for repairing a crack in an underwater part, wherein the filling state of the filling material is confirmed through the light-transmitting sheet material.   The method for repairing a crack in an underwater part according to claim 1, wherein at least two injection parts are provided.   The method for repairing a crack in an underwater part according to claim 1 or 2, wherein the injection part is formed by making a cut in the sheet material.   The method for repairing a crack in an underwater part according to any one of claims 1 to 3, wherein the thickness of the sheet material is 1 mm or more and 2 mm or less.   The method for repairing a crack in an underwater part according to any one of claims 1 to 4, wherein the filling material is injected into the injection part through a tip of a hand gun.

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