Mesh backing material

Abstract

To provide a backup material capable of maintaining adhesive force between a resin concrete panel and a joint caulking material even if spring water in a tunnel natural ground infiltrates into a gap between the resin concrete panel and the backup material after construction by a panel rising method.SOLUTION: A mesh backup material 10 is installed to prevent a joint caulking material from being pushed out to a back side (a side of an existing tunnel) of a resin concrete panel during caulking work in a panel lining method, and is characterized in that the mesh backup material 10 is made of a flat plate member 30 with a plurality of through holes 20, and the cross-sectional shape of the through holes 20 is a rectangle with each side measuring 3 mm to 5 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a backup material that is installed on the back side of a resin concrete panel (the side of the resin concrete panel facing an existing tunnel) to prevent the joint caulking material filled in the gap between resin concrete panels from being pushed out during joint caulking work in the panel lining method. [Background technology]

[0002] In recent years, a method using resin concrete panels (panel lining method) has been increasingly adopted for repairing the inner walls of waterway tunnels and the like. The panel lining method involves installing fixed steel materials such as H-shaped steel in the circumferential direction of the tunnel (at specified intervals in the tunnel axis direction) on the inner side of an existing tunnel (steel supports), installing panel fixing steel materials to connect the fixed steel materials, and then fixing (the resin concrete panel) to the panel fixing steel materials by bolting or the like, and further injecting a filler such as mortar into the gap between the resin concrete panel and the existing tunnel. With the panel lining method, resin concrete panels are used to repair and reinforce the inner walls of existing waterway tunnels and the like.

[0003] In the panel lining method, elastic epoxy resin is used as a joint caulking material to fill the gaps (called joints) between resin concrete panels, and plate-shaped PET resin etc. is used as a back-up material to prevent the caulking material from being pushed out to the back side of the resin concrete panel (the side of the existing tunnel). However, after construction, spring water present in the strata around the tunnel seeps into the gaps between the resin concrete panel and the back-up material, causing the adhesive strength between the resin concrete panel and the joint caulking material to decrease, causing the spring water to flow out of the joints (starting from the part where the spring water has seeped in), resulting in the adhesion of free lime (calcium oxide contained in cement that has not been able to combine with other substances) to adhere to the joints.

[0004] Patent Document 1 has the objective of "providing a heat-expandable joint material for exterior walls which is excellent in fire resistance and water resistance and easy to handle (Patent Document 1: Abstract)", and discloses "a heat-expandable joint material for exterior walls which includes a heat-expandable fire-resistant resin composition layer, the heat-expandable joint material for exterior walls being composed of a heat-expandable fire-resistant resin composition layer, the heat-expandable fire-resistant resin composition forming the heat-expandable fire-resistant resin composition layer containing 100 parts by weight of a resin component, 5 to 200 parts by weight of heat-expandable graphite, 20 to 200 parts by weight of a boron-containing compound, 10 to 70 parts by weight of an antimony-containing compound and 0.1 to 10 parts by weight of a vulcanizing agent, the resin component being at least one selected from the group consisting of EPDM, polybutene and polybutadiene, and which is molded by extrusion molding using the heat-expandable fire-resistant resin composition (Patent Document 1: Abstract)". [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-159731 A Summary of the Invention [Problem to be solved by the invention]

[0006] The thermally expandable joint material for exterior walls in Patent Document 1 (Patent Document 1: Title of the invention) has a cylindrical structure with a circular cross section, or a square prism structure with a rectangular cross section in the longitudinal direction. With such a shape, it cannot be used as a backup material for the joint caulking material filled in the gap between resin concrete panels, as in the present invention.

[0007] To provide a mesh-like backup material capable of maintaining the adhesive force between a resin concrete panel and a joint caulking material even if spring water in the tunnel ground seeps into the gap between the resin concrete panel and the backup material after construction. [Means for solving the problem]

[0008] In order to solve the above problems, the invention described in claim 1 is a backup material that is installed to prevent joint caulking material from being pushed out to the back side (existing tunnel side) of a resin concrete panel during caulking work in a panel lining method, and is characterized in that the mesh backup material consists of a mesh plate-like member with a plurality of through holes, and the cross-sectional shape of the through holes is a rectangle with each side measuring 3 mm to 5 mm.

[0009] The invention described in claim 2 is characterized in that the through holes are arranged at equal intervals in a mesh-like backup material in the invention described in claim 1. In this specification, "the through holes are arranged at equal intervals" means that the distances from the center of a through hole to the center of an adjacent through hole are all the same. Effect of the Invention

[0010] The present invention is a mesh-like backup material that is installed to prevent the joint caulking material from being pushed out to the back side of the resin concrete panel (the side of the existing tunnel) during caulking work in the panel lining method (filling the gaps between resin concrete panels with joint caulking material), and to improve the adhesion between the joint caulking material used in the caulking work and the resin concrete panel (by preventing spring water from seeping in between the resin concrete panel and the backup material using the adhesive strength of the grout material).

[0011] The mesh-like backup material is formed of a plurality of through holes and flat mesh-like members, and the cross-sectional shape of the through holes is a rectangle with one side measuring 3 mm to 5 mm. Even if groundwater or other spring water around the tunnel infiltrates, more specifically, even if the spring water tries to infiltrate between the resin concrete panel and the backup material, when the grout material is filled and injected into the back of the resin concrete panel, the grout material flows in through the through holes of the backup material and solidifies, thereby preventing the infiltration of groundwater or other spring water around the tunnel. Therefore, water leakage from the joints and adhesion of free lime are eliminated. In other words, it has become possible to maintain and improve the adhesion state between the joint caulking material used in the caulking work and the resin concrete panel.

[0012] Furthermore, all the through holes have the same volume (they have the same cross-sectional shape and the thickness of the flat mesh member is uniform), and the through holes are spaced at equal intervals in the flat mesh member, i.e., evenly spaced. Therefore, by filling and solidifying the grout material evenly at all the through holes in the backup material, the adhesive strength between the resin concrete panel and the backup material can be improved, preventing groundwater and other spring water around the tunnel from seeping in (between the gap between the joint caulking material and the resin concrete panel), eliminating problems such as water leakage from the joints and adhesion of free lime. [Brief description of the drawings]

[0013] [Figure 1] FIG. [Diagram 2] FIG. 13 is a diagram for explaining an installation state of a backup material. [Diagram 3] FIG. 2 is a diagram for explaining the difference between a conventional back-up material and a mesh-shaped back-up material according to the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <Structure of mesh-like backup material> An embodiment of a mesh-like backup material 10 according to the present invention will be described in detail below with reference to Figs. 1 to 3. Fig. 1 is an overall top view of the mesh-like backup material 10 according to the present invention. The direction in which the through holes 20 are arranged is different between Fig. 1(a) and Fig. 1(b). That is, in Fig. 1(a), the through holes 20 are arranged along the longitudinal direction of the mesh-like backup material 10, and in Fig. 1(b), the through holes 20 are arranged along a direction at an angle of 45° to the longitudinal direction of the mesh-like backup material 10. The mesh-like backup material 10 according to the present invention may be in either the form shown in Fig. 1(a) or Fig. 1(b).

[0015] To begin with, a backup material is a flat plate-shaped component (there was no through hole in the conventional type) that is installed to prevent the joint caulking material from being pushed out to the back side (the existing tunnel side) of the resin concrete panel during joint caulking work in the panel lining method. The material used for the backup material is mainly PET resin, but it is not limited to PET resin and any hard resin can be used.

[0016] As shown in FIG. 1, the mesh-like backup material 10 is a member having a plurality of through holes 20 and a flat mesh member 30. The length is about 100 cm, which is the length of the resin concrete panel, and the width is about 5 cm. The cross-sectional shape of the (plurality of) through holes 20 is a rectangle with a side of 3 mm to 5 mm, and the through holes 20 are arranged at equal intervals (the distance from the center of a through hole 20 to the center of an adjacent through hole 20 is the same) on the surface of the flat mesh member 30 (PET resin portion). That is, the through holes 20 all have the same cross-sectional area, and are arranged evenly on the surface of the flat mesh member 30 (PET resin portion).

[0017] The through holes 20 are arranged (positional relationship) at equal intervals on the surface of the flat mesh member 30 (PET resin portion), but are arranged so that the dimension to the adjacent through holes 20 (the dimension between the right end of a through hole 20 and the left end of the adjacent through hole 20) is about one third of the width of the through holes 20. More specifically, the dimension to the adjacent through holes 20 (the dimension between the right end of a through hole 20 and the left end of the adjacent through hole 20) is two-fifths to three-fifths of the width of the through holes 20. This is to enable the joint caulking material 15 to be supported by the flat mesh member 30 (PET resin portion) between the through holes 20 and the adjacent through holes 20.

[0018] <Mesh back-up material installation status> 2 is a diagram for explaining the installation state of the mesh-like backup material 10. The mesh-like backup material 10 is a member that is installed (in advance) on the back side (existing tunnel side) of the joint between the resin concrete panels 13 before the joint caulking material 15 (the joint caulking material 15 is not filled immediately after the backup material 10 is installed) is filled into the gap between the resin concrete panels 13 by joint caulking work. In other words, it is a member that is installed to back up (support) the joint caulking material 15 on the back side (existing tunnel side) of the joint caulking material 15 that is filled (by the joint caulking material 15 injection process).

[0019] The purpose of the backup material is to prevent the joint caulking material 15 filled in the joints between the resin concrete panels 13 from being pushed out. The joint caulking material 15 itself has a certain degree of viscosity and does not flow down like a liquid, but it can be said that a certain degree of backup (backing) is necessary to prevent the joint caulking material 15 from being pushed out. If a gap is created between the backup material and the resin concrete panel 13 (as shown in Figure 3), that is, if the pressing force is small, the adhesive strength between the joint caulking material 15 and the resin concrete panel 13 will be low.

[0020] <Effects of mesh-type backup material> 3 is a diagram for explaining the difference between a conventional backup material (a) and the mesh-like backup material 10 (b) according to the present invention. In the panel lining method, flat PET resin or the like (without through holes) has been used (conventionally) as a backup material for backing up (backing up) the joint caulking material 15 (elastic epoxy resin) that fills the gaps (called joints) between the resin concrete panels 13.

[0021] When installing the resin concrete panels 13, one backup material is attached to each resin concrete panel (either to the right or left end). In other words, it is attached to only one side of the resin concrete panel. Therefore, the backup material is attached (in advance) to the resin concrete panel 13 that was installed first, but the backup material is not attached to the resin concrete panel 13 that is installed later (it is attached to the opposite side). When installing the resin concrete panel 13 later, the backup material is subjected to a pushing force when the resin concrete panel 13 is installed, so the backup material sags slightly (see the left diagram in Figure 3(a) before grout material is injected).

[0022] With conventional backup materials (without through holes), when grout is injected, the backup material sags slightly, causing a gap between the resin concrete panel and the backup material, which remains as a gap (even after grout is injected) (see the right diagram in Figure 3(a) after grout is injected). As a result, after construction using the panel lining method, spring water in the strata around the tunnel seeps into the gap between the resin concrete panel 13 and the backup material, causing a decrease in the adhesive strength between the resin concrete panel 13 and the joint caulking material 15, which causes the spring water to flow out of the joint (starting from the part where the spring water has seenp in), resulting in the adhesion of free lime to the backup material (see the right diagram in Figure 3(a) after grout is injected).

[0023] In order to solve such problems, the backup material 10 according to the present invention is provided with a plurality of through holes 20, that is, formed of a flat mesh member 30 (the cross-sectional shape of the through holes 20 is a rectangle with one side measuring 3 mm to 5 mm). By providing the through holes 20, when the grout material is filled and injected into the back surface of the resin concrete panel 13, the grout material flows in and solidifies through the through holes 20 (of the mesh backup material 10). Therefore, the gap between the mesh backup material 10 and the resin concrete panel 13, which occurs when the mesh backup material 10 sags slightly, is filled with the grout material, eliminating the gap.

[0024] Therefore, even if groundwater or other spring water around the tunnel tries to infiltrate into the gap between the resin concrete panel 13 and the backup material 10, it is possible to prevent the infiltration of groundwater or other spring water around the tunnel, thereby preventing water leakage from the joints and the adhesion of free lime. In other words, it has become possible to maintain and improve the adhesion between the joint caulking material 15 used in the caulking work and the resin concrete panel 13 (see Figure 3(b)).

[0025] Furthermore, since all of the through holes 20 have the same volume (they have the same cross-sectional shape and the thickness of the flat mesh member 30 is uniform) and are arranged at equal intervals on the surface of the flat mesh member 30, the grout material is evenly filled and hardened in all of the through holes 20 of the backup material 10, thereby improving the adhesion to the resin concrete panel 13 and eliminating problems such as water leakage from the joints and adhesion of free lime caused by groundwater and other spring water around the tunnel penetrating (into the gap between the joint caulking material 15 and the resin concrete panel 13).

[0026] <Example of changing backup material> The backup material of the present invention is not limited in any way to the aspects of the above-mentioned embodiments, and the configuration of the through holes, flat mesh members, etc. can be appropriately modified as necessary without departing from the spirit of the present invention. [Industrial Applicability]

[0027] Since the backup material of the present invention has the excellent effects as described above, it can be suitably used as a backup material to be installed on the back side of a resin concrete panel (the side of the resin concrete panel facing the existing tunnel) so that the joint caulking material filled in the gap between resin concrete panels is not pushed out during joint caulking work in the panel lining method. [Explanation of symbols]

[0028] 10. Mesh back-up material 13. Resin concrete panel 15. Joint caulking material 20··Through hole 30...Flat mesh member

Claims

1. This is a backup material that is installed to prevent the joint caulking material from being pushed out to the back side of the resin concrete panel (the side of the existing tunnel) during caulking work in the panel lining method. A mesh plate member having a plurality of through holes, A mesh-like backup material, characterized in that the cross-sectional shape of the through holes is a rectangle with each side measuring 3 mm to 5 mm.

2. 2. The mesh backup material according to claim 1, wherein the through holes are arranged at equal intervals.

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