Repair jig and repair method for prestressed concrete structures

Abstract

To provide a means for reliably fixing a grout hose 50 to a drilled hole C and enabling better injection of grout material D, even when the diameter of the drilled hole C is larger than the diameter of the grout hose 50, in repair work of a PC (prestressed) structure. [Solution] A repair jig A includes a lid portion 10 having a cross-sectional shape substantially the same as the cross-sectional shape of a drilled hole C in a PC structure B and having an injection hole 11 and an air vent hole 12 penetrating in the front-to-rear direction, a flange portion 20 extending forward and / or rearward from the lid portion 10 and capable of contacting the inner peripheral surface of the drilled hole C, and a connection portion 30 extending tubularly rearward from the injection hole 11 and capable of connecting a grout hose 50. First, the PC structure B is drilled to provide a drilled hole C communicating with the repair location, the repair jig A is inserted into the drilled hole C and fixed in place, and grout material D is injected from the grout hose 50 connected to the connection portion 30, filling the repair jig A and closing the drilled hole C, thereby repairing the PC structure B.

Description

[Technical Field]

[0001] The present invention relates to a repair jig and a repair method for PC (prestressed concrete) structures, and more particularly to a repair jig and a repair method used to reinject grout material into cavities in a sheath to perform repairs. [Background technology]

[0002] The methods shown in Patent Document 1 and Non-Patent Document 1 below have been proposed as a method of repairing cavities that have occurred due to insufficient filling of grout material into sheaths embedded in existing PC structures by re-injecting grout material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6831985 [Non-patent literature]

[0004] [Non-Patent Document 1] https: / / www.pcken.or.jp / wordpress / wp-content / uploads / 2023 / 02 / grout_qa.pdf Summary of the Invention [Problem to be solved by the invention]

[0005] In actual construction, the drilled hole must be enlarged to a size large enough for the worker to insert his or her hand, in order to push the air-bleeding hose into the sheath and insert it to the required position. In this case, the diameter of the drilled hole becomes larger than the diameter of the grout hose, and the above-mentioned prior art documents do not suggest any effective means of fixing the grout hose to the drilled hole in a way that can adequately withstand the injection pressure of the grout material.

[0006] Therefore, one of the objects of the present invention is to provide a means for securely fixing a grout hose to a drilled hole, thereby enabling better injection of grout material, even when the diameter of the drilled hole is larger than the diameter of the grout hose, during repair work on PC structures. [Means for solving the problem]

[0007] The present invention, which has been made to solve the above problems, is a repair jig for repairing a cavity in a sheath of a PC (prestressed concrete) structure by re-injecting grout material into the cavity, and the repair jig comprises a cover having a shape substantially the same as the cross-sectional shape of the drilled hole in the PC structure, an injection hole and an air vent hole penetrating in the front-rear direction, and a periphery of the cover. Edge only From, forward and / or backward and the extending portion is Inner surface of the drilled hole to The grout hose is connected to the flange portion, and the flange portion extends rearward from the injection hole. the lid portion, the flange portion, and the connecting portion are made of metal or resin, The repair jig has a feature that it has no contact points with the outer surface of the PC structure, and all parts of it are accommodated in the drilled hole and buried. The present invention also provides ,before The tip of the flange may be a portion that comes into contact with the deepest part of the drilled hole. In the present invention, the flange may be provided around the entire periphery of the lid. In the present invention, the flange may be provided intermittently on the periphery of the lid. In the present invention, the injection hole may be provided with a check valve. The present invention also provides a repair method for repairing a cavity in a sheath of a PC (prestressed concrete) structure by re-injecting grout material into the cavity, characterized by comprising at least the steps of: (a) drilling a PC structure to provide a drilled hole that communicates with the repair location; (b) inserting a repair jig described in any one of claims 1 to 5 into the drilled hole and fixing the repair jig within the drilled hole; (c) pressurizing grout material from a grout hose connected to the connection portion; and (d) sealing the drilled hole while burying the repair jig. Further, in the present invention, in the (b), the tip of the flange portion is Consists of a cylindrical shape only The repair jig may be configured to be fixed within the drilled hole in a state where it is in contact with the deepest part of the drilled hole. [Effects of the Invention]

[0008] According to the present invention, the grout injection work can be carried out well. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic perspective view showing a repair jig according to a first embodiment. [Figure 2] FIG. 10 is a schematic perspective view showing another example of a repair jig. [Figure 3] An image of the repair method according to the present invention (1). [Figure 4] An image of the repair method according to the present invention (2). [Figure 5] FIG. 10 is a schematic perspective view showing a repair jig according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present invention, the term "front" refers to the direction toward the back of the drilled hole when the repair jig of the present invention is installed in the drilled hole provided in the PC structure, and the term "rear" refers to the direction toward the front of the drilled hole. Each part will be described in detail below. [Example]

[0011] <1> Overall configuration (Fig. 1) The repair jig A of the present invention (hereinafter also referred to simply as "repair jig A") is a component to be installed in a drilled hole provided in a PC structure B, and comprises at least a cover portion 10, a flange portion 20, and a connection portion 30. In the present invention, the material of each part is not particularly limited, and any material such as metal or resin can be selected or combined. However, it is preferable to use a material that does not have a risk of adversely affecting the PC structure B when the repair jig A is buried in the drilled hole C.

[0012] <2> Lid (Figure 1) The lid portion 10 is a portion that functions as a blocking lid to prevent the pressed grout material from leaking out of the drilled hole C during the grout injection work. Therefore, the cover 10 needs to have a shape that is substantially the same as the cross-sectional shape of the drilled hole. The lid portion 10 is provided with an injection hole 11 and an air vent hole 12 that penetrate the lid portion 10 in the front-rear direction.

[0013] <2.1> Injection hole (Fig. 1) The injection hole 11 is a portion that functions as an inflow path for the grout material. In the present invention, the position and number of injection holes 11 are not particularly limited. In this embodiment, one injection hole 11 is provided. A cylindrical connecting portion 30, which will be described later, is provided behind injection hole 11.

[0014] <2.2> Air vent hole (Fig. 1) The air vent hole 12 is a portion through which an air vent hose is inserted. In the present invention, there are no particular limitations on the position, shape, or number of air vent holes 12 in the lid 10. In addition, a configuration in which cylindrical portions, such as connecting portions 30 described below, are provided before and after the air vent hole 12, is not excluded. In this embodiment, two air vent holes 12 are provided through the cover 10 in the front-rear direction. The air vent hole 12 has a diameter that allows the air vent hose 60 to be inserted therethrough, and is used to push the air vent hose into a predetermined position within the repaired portion of the PC structure after the air vent hose has been inserted.

[0015] <3> Flange (Fig. 1) The flange portion 20 is a portion for increasing the stability of the posture of the repair jig A in the drilled hole when the repair jig A according to the present invention is placed in the drilled hole.

[0016] <3.1> Extension direction of flange (Fig. 1) In the present invention, the direction in which the flange 20 extends is not particularly limited, and the flange 20 can be extended in front of or behind the lid 10, or a combination thereof, as appropriate. However, it is preferable that the flange 20 be provided so as to extend in front of the lid 10. The reason for this is that <5> This will be discussed later in the section.

[0017] <3.2> Flange arrangement (Fig. 1, Fig. 2) In the present invention, the arrangement of the flange portion 20 is not particularly limited, and for example, it may be provided around the entire periphery of the cover portion 10 as shown in Figure 1, or it may be provided intermittently as shown in Figure 2. Any configuration is sufficient as long as the repair jig A installed in the drilled hole C can be stably maintained in its position within the drilled hole until it is positioned by some kind of fixing means before the grout material is injected.

[0018] <4> Connection part (Fig. 1) The connection portion 30 is a portion for connecting a grout hose. In the present invention, the form of the connection part 30 is not particularly limited, and any form may be adopted as long as it can send the grout material D sent from the connected grout hose to the injection hole 11. In this embodiment, a tubular member having an outer diameter approximately the same as the inner diameter of the grout hose is welded to the periphery of the injection hole 11 to form the connection portion 30 .

[0019] <5> How to use (repair) (Fig. 3, Fig. 4) Next, the procedure for using the repair jig A according to the present invention (method for repairing a PC structure) will be described with reference to the drawings. The operations described below can be interchanged or performed simultaneously as long as there is no contradiction in the process.

[0020] <5.1> Drilling holes - grout injection (Fig. 3) FIG. 3 is a diagram showing the arrangement of the components at the stage of injecting the grout material D. The outline of the work up to this stage is as follows:

[0021] (1) Drilling holes - Installing repair jigs After drilling a hole C communicating with the repair location in the PC structure B, the repair jig A according to the present invention is inserted into the drilled hole C up to a predetermined position. At this time, there are no particular restrictions as to whether or not the grout hose 50 is connected to the connection portion 30 in advance, and / or whether or not the air vent hose 60 is inserted into the air vent hole 12 in advance, and these may be selected as appropriate.

[0022] Details of the repair jig A shown in FIG. 3 are as follows. Thickness of the cover 10, flange 20 and connection 30: 2 mm Diameter of the lid 10: 100 mm (the injection hole 11 and the lid 10 share the same axis) Extension length of flange 20: 20 mm (the flange 20 is formed around the entire periphery of the lid 10) Injection hole diameter: 15mm Diameter of air vent hole 12: 9 mm (the number of air vent holes 12 was two) Distance from the center of injection hole 11 to the center of air vent hole 12: 30 mm Extension length of connection part 30: 30 mm Outer diameter of connector 30: 19mm

[0023] (2) Unwinding the air vent hose The repair jig A is placed inside the drilled hole C. At this time, the repair jig A can be placed so that the tip of the flange portion 20 is inserted all the way into the drilled hole C so as to abut the deepest part of the hole. The air vent hose 60 inserted into the air vent hole 12 is pushed in, and the tip of the air vent hose 60 is fed through the gap between the sheath B1 and the PC steel B2 to a predetermined position in the longitudinal direction within the sheath B1 (the front-to-back direction on the paper in Figure 3). After the air vent hose 60 is pushed into a predetermined position, the gap between the air vent hole 12 and the air vent hose 60 is blocked with any material (adhesive or sealant) to prevent the grout material from leaking out from the gap.

[0024] (3) Fixing the repair jig The repair jig A is fixed to the drilled hole C while filling the gap between the outer peripheral edge of the lid portion 10 and the inner peripheral surface of the drilled hole C with adhesive 40 such as epoxy resin. At this time, the repair jig A according to the present invention can be reliably positioned by positioning the tip of the flange 20 extending forward from the lid 10 so that it abuts against the deepest part of the drilled hole C. Furthermore, since an excess length equivalent to the extension length of the flange 20 can be reliably maintained between the deepest part of the drilled hole C and the lid 10, the grout material D can be fed into the sheath B1 while filling the space secured between the injection hole 11 and the PC material with the grout material D.

[0025] <5.2> Closing of drilled holes (Fig. 4) FIG. 4 shows the state after repairs are completed. After the grout material D has been pressed in, the grout hose 50 is removed from the connection part 30, and the repair jig A is left in the drilled hole C, and the drilled hole C is filled with a filler material E such as mortar to close the drilled hole C.

[0026] <6> summary As described above, the repair jig and repair method according to the present invention provide at least one of the following effects. (1) By connecting the grout hose 50 to the connection portion 30 extending from the cover portion 10, which has a shape approximately the same as the cross-sectional shape of the drilled hole C, the injection work of the grout material D can be carried out smoothly even if the diameter of the drilled hole C is larger than the diameter of the grout hose 50. (2) The flange portion 20 extending from the lid portion 10 comes into contact with the inner peripheral surface of the drilled hole C, thereby stabilizing the position of the lid portion 10 provided with the connecting portion 30 within the drilled hole C. (3) By configuring the flange portion 20 to extend forward from the cover portion 10, the tip of the flange portion 20 can be pushed in so that it abuts against the deepest part of the drilled hole C, thereby enabling the repair jig A to be installed in a predetermined position while reliably avoiding contact between the sheath B1 and the PC steel B2 and the cover portion 10. (4) By configuring the flange portion 20 to extend forward from the lid portion 10, an excess length equivalent to the extension length of the flange portion 20 can be reliably maintained between the deepest part of the drilled hole C and the lid portion 10, so that the grout material D can be filled into the space secured between the injection hole 11 and the PC material while being sent into the sheath B1. (5) By providing the flange portion 20 around the entire periphery of the cover portion 10, the posture of the repair jig A within the drilled hole C becomes more stable. [Example]

[0027] <1> Overall configuration (Fig. 1) A repair jig A according to a second embodiment of the present invention is shown in FIG. The repair jig A according to this embodiment has a structure in which a check valve 13 is provided in an injection hole 11 provided in a lid portion 10 . This check valve 13 is to be positioned in a direction that allows the flow of grout material from the drilled hole C into the inside of the PC structure B. According to the configuration of this embodiment, it is possible to suppress the risk of the grout material press-injected into the PC structure B leaking out from the injection hole 11 after the grout hose 50 is removed. [Explanation of symbols]

[0028] A: Repair jig 10: Lid 11: Injection hole 12: Air vent hole 13: Check valve 20: Tsuba section 30: Connection 40: Adhesive 50:Grout hose 60: Air bleed hose B: PC structure B1: Sheath B2:PC steel material C: Drilling hole D: Grout material E: Filler

Claims

1. A repair jig for repairing a cavity in a sheath of a PC (prestressed concrete) structure by re-injecting grout material, a cover portion having an injection hole and an air vent hole penetrating in the front-rear direction and having a shape substantially the same as the cross-sectional shape of the drilled hole of the PC structure; a flange portion having a portion extending forward and / or rearward from only the outer peripheral edge of the lid portion, at least forward, and capable of contacting the extending portion with the inner peripheral surface of the drilled hole; A connection portion extending rearward from the injection hole to which a grout hose can be connected; and the lid portion, the flange portion, and the connecting portion are made of metal or resin, The repair jig has no contact with the outer surface of the PC structure, and all parts are accommodated in the drilled hole and buried. Repair jig for PC structures.

2. The tip of the flange is a portion for abutting against the deepest part of the drilled hole. The repair jig for a PC structure according to claim 1.

3. The flange is provided around the entire periphery of the lid. The repair jig for a PC structure according to claim 1.

4. The flange is provided intermittently on the periphery of the lid. The repair jig for a PC structure according to claim 1.

5. The injection hole is provided with a check valve. The repair jig for a PC structure according to claim 1.

6. A repair method for repairing a cavity in a sheath of a PC (prestressed concrete) structure by re-injecting grout material, (a) drilling a PC structure to provide a drilled hole communicating with the repair location; (b) inserting the repair jig according to any one of claims 1 to 5 into the drilled hole and fixing the repair jig in the drilled hole; (c) pressurizing the grout material from the grout hose connected to the connection portion; (d) a step of filling the drilled hole while burying the repair jig; characterized by having at least Repair method for PC structures.

7. In (b), the repair jig is fixed in the drilled hole with the tip of the flange portion abutting against the deepest part of the drilled hole consisting only of a cylindrical shape. The method for repairing a PC structure according to claim 6.

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