Metal pipe reinforcement method and reinforcement material

Abstract

To provide an easily executable reinforcing method for a metallic pipe.SOLUTION: A reinforcing method for a metallic pipe related to the present invention includes a step of inserting a cylindrical reinforcing material 100 into a metallic pipe P, injecting a fluidizing solidification material into the inserted reinforcing material 100 and pressing the reinforcing material 100 to an inner wall of the metallic pipe P. As the reinforcing material 100, a plain-woven fiber bundle fabric formed of warps 10 formed of fiber bundles formed by bundling a lot of chemical fibers and wefts 20 connecting the fiber bundles forming the warps 10 with each other is cylindrically formed with the warps 10 set in the vertical direction, and an adhesive layer is formed on an outer surface of the cylindrical form, which is used as the reinforcing material 100.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to the reinforcement (repair) of metal pipes such as road lighting poles. [Background technology]

[0002] For example, road lighting poles that are erected with their lower ends planted in the ground are susceptible to corrosion below ground level, so they are sometimes reinforced using a reinforcement technique such as that disclosed in Patent Document 1. Patent Document 1 discloses a reinforcement method in which a large number of aramid rods are regularly arranged inside the hollow pole below ground level using spacers, and then a fluid hardening material such as mortar is injected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2012-225019 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned reinforcement methods of the prior art have an issue in that the placement of the aramid rods is time-consuming. Also, in the case of road lighting poles, electrical wiring is installed inside them, so a reinforcement technique that can reinforce metal pipes with such internal parts without any problems is also required. [Means for solving the problem]

[0005] The proposed method for reinforcing a metal pipe according to the present invention includes the steps of inserting a cylindrical reinforcing material into the metal pipe, injecting a fluid solidifying agent into the inside of the inserted reinforcing material, and pressing the reinforcing material against the inner wall of the metal pipe. The reinforcing material is characterized by the use of a plain-weave fiber bundle fabric, which is made of warp yarns each consisting of fiber bundles of a large number of chemical fibers and weft yarns connecting the fiber bundles that make up the warp yarns, shaped into a cylindrical shape with the warp yarns oriented axially and with an adhesive layer formed on its outer surface. This reinforcing material is bendable at the joints where the weft yarns of the plain weave pass between the warp yarns (i.e., the parts where the weft yarns pass between the warp yarns from front to back) form joints, connecting the warp yarns like hinges. In one embodiment, the weft thread can be woven so that it passes between every few warp threads, transitioning from front to back and rising and sinking, and in this embodiment, the warp threads are hinge-connected with joints at the points where the weft threads pass between every few warp threads. [Effects of the Invention]

[0006] In the reinforcing method and reinforcing material according to the present invention, for example, if the warp fiber bundles are a fiber bundle fabric made of aramid fibers, the tubular reinforcing material can be inserted into a metal pipe to arrange aramid rods along the inner wall of the pipe simply by the method. Furthermore, since the reinforcing material is bendable between the warp threads, even if there is electrical wiring or the like inside the metal pipe, the reinforcing material can deform along the wiring, thereby providing reinforcement without any problems. [Brief explanation of the drawings]

[0007] [Figure 1] (A) Plan view of the fiber bundle fabric (sheet-like) that forms the reinforcing material, (B) End view explaining how the weft threads are woven, (C) Cross-sectional view of the fiber bundles that form the warp threads. [Figure 2] 2 is a diagram showing the fiber bundle fabric of FIG. 1 formed into a cylindrical shape. [Figure 3] A diagram showing how a reinforcing material is inserted into a metal pipe through an opening in the pipe. [Figure 4] FIG. 10 shows a reinforcement inserted into a metal pipe and pressed against the inner wall. [Figure 5]A diagram explaining the deformation of the cylindrical fiber bundle fabric of Figure 1. [Figure 6] FIG. 10 shows another example of a reinforcing member inserted into a metal pipe and pressed against the inner wall. [Figure 7] 7 is a diagram showing the state in which the reinforcing material of the example of FIG. 6 is inserted into the metal pipe through the opening of the pipe. DETAILED DESCRIPTION OF THE INVENTION

[0008] FIG. 1(A) shows a plan view of a fiber bundle fabric for producing a reinforcing material according to the present invention. The fiber bundle fabric 1 constituting the reinforcing material is a plain weave fabric composed of warp yarns 10 and weft yarns 20. Each warp yarn 10 is composed of fiber bundles formed by bundling numerous chemical fibers. These warp fiber bundles 10 are arranged in a horizontal row with their extension direction Y parallel to one another and are interconnected by weft yarns 20. As shown in FIG. 1(B), the weft yarns 20 pass between every few warp fiber bundles 10 (every third in this embodiment), transitioning from front to back and back to front, and rising and falling as they are woven. Every third warp fiber bundle 10 is hinge-connected at the inter-warp passing portion 21 of the weft yarn. In this case, the warp fiber bundles 10 can also be glued together in groups of three.

[0009] As can be seen from FIGS. 1(A) and 1(B), in this embodiment, the warp fiber bundles 10 are bundled in groups of three by the weft yarns 20 tensioned by the weaving method described above, and these three fibers are tightly secured together. Meanwhile, since the weft yarns 20 move from one warp yarn to the other, the fiber bundles 10 corresponding to the inter-warp passing portions 21 of the weft yarns 20 that appear every third warp are separated by gaps of, for example, 0.1 mm to 1 mm depending on the material (or thickness) of the weft yarns 20. Therefore, the warp fiber bundles 10 are hinged at the inter-warp passing portions 21, and as shown in FIG. 1(B), the fiber bundle fabric 1 bends at the inter-warp passing portions 21. The inter-warp passing portions 21 of the weft yarns 20 can be cut by inserting a blade such as a cutter into the gaps between the warp yarns, and thus also function as separation points for the warp yarns 10. Such weft yarns 20 can be made of polyethylene or polypropylene.

[0010] As shown in the cross-sectional view of FIG. 1(C) (showing one fiber bundle), the fiber bundles 10 forming the warp yarns are formed by bundling a large number of long, high-strength fibers (e.g., aramid fibers) 11, each stretching in the stretching direction Y, and then impregnating and solidifying them with a phenolic, polyester, epoxy, or acrylic resin. The thickness of a single fiber bundle 10 formed by bundling aramid fibers 11 is, for example, 500 decitex (dtex), and a diameter of 0.5 mm to 5 mm is preferable in terms of reinforcing strength. Furthermore, the hardness of the impregnated resin is preferably 80 or less (Rockwell hardness) in order to process the fiber bundle fabric 1.

[0011] The fiber bundle fabric 1 of the above configuration is rolled up so that the stretching direction Y of the warp yarns 10 is the axial direction of the cylinder, that is, it is formed into a cylindrical shape with the warp yarns 10 oriented axially as shown in Figure 2, and is used as a reinforcing material. Because the warp yarns 10 are hinged at the warp passage portion 21, the fiber bundle fabric 1 can be easily formed into a cylindrical shape by bending this portion. When the fiber bundle fabric 1 of Figure 1(A) is formed into a cylindrical shape, the butted ends (the left and right side edges in Figure 1(A)) can be bound and connected with a binding material made of the same material as the weft yarns 20. Alternatively, it is also possible to simply roll up the fabric into a cylindrical shape and leave the ends free and unconnected.

[0012] An adhesive layer is formed on the outer surface of the fiber bundle fabric 1 shown in Fig. 2 rolled into a cylindrical shape. The adhesive layer can be formed by applying a curable resin such as an epoxy resin to the outer surface. The adhesive layer is preferably formed to be thicker than the diameter of the weft yarns 20. In forming this adhesive layer, the warp yarns 10 in this example are grouped in groups of three and form a single plate, which makes it easier to apply a thick adhesive and form a layer, and also makes it possible to increase the surface area of ​​the adhesive layer.

[0013] 3 and 4 are simplified diagrams illustrating a process for reinforcing a metal pipe using a reinforcing material 100 after forming an adhesive layer on the cylindrical fiber bundle fabric 1 of FIG. 2.

[0014] The metal pipe P is, for example, a road lighting pole erected on a road, with its lower end surrounded by concrete and embedded in the ground. This metal pipe P has an opening O at a predetermined position above ground level for internal inspection, etc., which is normally closed with a lid (not shown). In this example, corrosion has occurred in the metal pipe P below ground level.

[0015] The reinforcing material 100 can be folded at the warp passage portion 21, and is inserted into the metal tube P through the opening O in a folded, puckered state. The reinforcing material 100 shown in Figures 3 and 4 is shown in gray to indicate that an adhesive layer is formed on the outer surface. Although the weft threads 20 are depicted in Figures 3 and 4, this is for the purpose of explanation, and the weft threads 20 are actually covered with an adhesive layer.

[0016] The reinforcing material 100 inserted into the metal pipe P unfolds (or is unfolded) from its folded state and returns to the cylindrical shape shown in FIG. 2, standing upright inside the metal pipe P. Then, a fluid solidifying material is injected from a pump using a hose or the like into the inside of the standing reinforcing material 100, forcing the reinforcing material 100 to unfold from the inside and press it against the inner wall of the metal pipe P (FIG. 4). The fluid solidifying material is, for example, mortar, and hardens after curing. When this fluid solidifying material is injected, because multiple warp threads 10 are bundled together, there are few gaps through which the fluid solidifying material can leak out of the reinforcing material 100, resulting in a leak-resistant structure.

[0017] Because an adhesive layer is formed on the outer surface of the reinforcing material 100, the reinforcing material 100 pressed against the inner wall of the metal pipe P is fixed to the metal pipe P as the adhesive hardens, and the warp yarns 10 made of fiber bundles act as reinforcing materials. Furthermore, the adhesive in the adhesive layer formed on the outer surface seeps into the corrosion through holes that have opened in the pipe wall due to corrosion, filling in the corroded irregularities. Therefore, the corroded area is reinforced and repaired from both the inside and outside of the metal pipe P.

[0018] In the case of a metal pipe in which electrical appliances such as road lighting are installed, there is a hole for the power line in the underground buried part (the part inside the concrete in Figures 3 and 4), through which the power line is drawn into the metal pipe and led through the metal pipe to the electrical appliance mounted at the end of the metal pipe. When such internal parts such as electrical wiring are present inside the metal pipe, the fiber bundle fabric 1 bends at the inter-warp passing part 21 as a joint, so this reinforcing material 100 can deform along the internal parts, as shown in Figure 5. In other words, the reinforcing material 100 made of the fiber bundle fabric 1 shown in Figure 5 has a part recessed inward along the internal parts such as the wiring pipe.

[0019] FIG. 6 shows an example of reinforcement in which an opening O for inserting a reinforcing material 100 is newly formed in a metal pipe P. The opening O is a new opening created on-site to insert the reinforcing material 100 and is closed with a separately prepared lid or the like after the reinforcement is installed. The reinforcing material 100 is the same as the one described above, but its axial length is fabricated to extend above the opening O. That is, when the reinforcing material 100 is inserted into the metal pipe P and stands upright, the opening O is blocked from the inside by the reinforcing material 100. The reinforcing material 100 has an injection port or injection tube 30, which is connected to a hose or the like for injecting a fluid solidification material at a location corresponding to the opening O. The fluid solidification material is injected through this injection port or injection tube 30. After the fluid solidification material is injected, the injection port or injection tube 30 is sealed. Alternatively, a solidification material injection hose can be introduced into the metal pipe P from further above, and the fluid solidification material can be injected into the reinforcing material 100 from above.

[0020] The opening O would be a defect in the metal pipe P, which could result in a decrease in strength if left as is, but the defect is covered and reinforced by the reinforcing material 100, so strength is not lost but rather increased. In the case of thin sheet-like lining materials used to reinforce metal pipes in conventional technology, when applied in the same manner as in this example, the pressure of the solidification material injection causes the lining material to protrude from the opening O, causing problems. However, the reinforcing material 100 of the present invention, as described above, has warp threads 10 made of chemical fiber bundles and is therefore strong, so it can adequately withstand the solidification material injection pressure and will not bend and protrude from the opening O.

[0021] To insert a reinforcing member 100 that is taller than the opening O in this example, first, as shown in Figure 7, the reinforcing member 100 is inserted upward into the metal pipe P from the opening O. Then, when the entire reinforcing member 100 is inside the pipe, the reinforcing member 100 is lowered to assume the upright state shown in Figure 6. Other than this insertion procedure, the procedure is the same as that described for the examples of Figures 3 and 4. [Explanation of symbols]

[0022] 1. Fiber bundle fabric 10 Warp 11. Chemical fibers 20 weft threads 21 Warp thread passing section 100 Reinforcement P metal tube O opening

Claims

1. A method for reinforcing a metal pipe, comprising: The method includes a step of inserting a cylindrical reinforcing material into a metal pipe, and injecting a fluid solidifying material into the inserted reinforcing material to press the reinforcing material against the inner wall of the metal pipe, The reinforcing material is a plain weave fiber bundle fabric made of warp threads, each of which is made of fiber bundles formed by bundling a large number of chemical fibers, and weft threads that interconnect the fiber bundles that make up the warp threads, wherein the weft threads in the reinforcing material pass between every other warp thread and are woven in so as to move from the front to the back or vice versa, rising and sinking, and the plurality of warp threads are fixed in close contact with each other, and the warp threads are hinged and bendable with joints at the warp-to-warp passage points of weft threads that are every other warp thread, and the fiber bundle fabric is formed into a cylindrical shape with the warp threads axially aligned, and an adhesive layer is formed on the outer surface of the cylindrical shape to a thickness greater than the diameter of the weft threads.

2. A reinforcing material used to reinforce a metal pipe, A reinforcing material produced by forming a plain weave fiber bundle fabric consisting of warp threads, each consisting of fiber bundles made up of a large number of chemical fibers, and weft threads connecting the fiber bundles that make up the warp threads to each other, wherein the weft threads pass between every other warp thread and are woven so as to rise and fall, moving from the front to the back or vice versa, and the plurality of warp threads are fixed in close contact with each other, and the warp threads are hinged and bendable using the warp-to-warp passage parts of the weft threads that are every other warp thread as joints, into a cylindrical shape with the warp threads axially oriented, and an adhesive layer is formed on the outer surface with a thickness greater than the diameter of the weft threads.

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