JP7357438B2 - Reinforcement method and reinforcing material for metal pipes - Google Patents

Description

The present invention relates to reinforcing (renovating) metal tubes such as road lighting poles.

For example, road lighting poles that are erected with their lower ends planted underground are likely to suffer corrosion in the areas below the ground, so they are reinforced using the reinforcement technology disclosed in Patent Document 1. may be done. What is disclosed in Patent Document 1 is that a large number of aramid rods are regularly arranged inside a hollow column below the ground using spacers, and a fluid solidifying material such as mortar is injected. This is a reinforcement method.

JP2012-225019

The above reinforcement method of the prior art has an improvement in that the arrangement of the aramid rods is time-consuming. Furthermore, in the case of road lighting poles, electrical wiring is arranged inside the poles, so there is a need for reinforcement techniques that can be used to reinforce even metal tubes with such internal parts without any problems.

The reinforcing method according to the present invention proposed for reinforcing a metal pipe involves inserting a cylindrical reinforcing material into a metal pipe, injecting a fluid solidifying material into the inside of the inserted reinforcing material, and reinforcing the reinforcing material. The reinforcing material includes a process of pressing fibers against the inner wall of a metal tube, and as a reinforcing material, plain weave fibers are made of warp yarns, each consisting of a fiber bundle made of a large number of chemical fibers, and a weft yarn that interconnects the fiber bundles that make up the warp yarns. The present invention is characterized in that the bundled fabric is formed into a cylindrical shape with the warp in the axial direction, and a reinforcing material having an adhesive layer formed on the outer surface thereof is used. In this reinforcing material, the portion where the weft threads pass between the warp threads forming a plain weave (that is, the portion where the weft threads pass between the warp threads from front to back) forms a joint, and the warp threads are hinge-connected, so the joint portion It can be bent. In one embodiment, the weft threads can be woven so as to pass between the warp threads every plurality of the warp threads, move to the front and back, and float up and down. The warp threads are hinge-connected by using the inter-warp passing portions of the weft threads at intervals as joints.

For example, if the fiber bundle forming the warp is a fiber bundle fabric made by bundling aramid fibers, the reinforcing method and reinforcing material according to the present invention can be applied to the inner wall of the pipe by simply inserting a cylindrical reinforcing material into the metal pipe. Aramid rods can be reinforced along the Furthermore, since the reinforcing material can be bent between the warp yarns, even if there is electrical wiring inside the metal tube, the reinforcing material deforms along with this, and the reinforcing can be performed without any problem.

(A) A plan view of a fiber bundle fabric (sheet-like) forming a reinforcing material, (B) an end view illustrating how to weave wefts, and (C) a cross-sectional view of a fiber bundle forming a warp. FIG. 2 is a diagram showing the fiber bundle fabric of FIG. 1 in a cylindrical shape. FIG. 3 is a diagram illustrating how a reinforcing material is inserted into the metal tube from the opening of the tube. A diagram showing a reinforcing material inserted into a metal tube and pressed against an inner wall. FIG. 2 is a diagram illustrating a state in which the cylindrical fiber bundle fabric of FIG. 1 is deformed. The figure which shows another example of the reinforcing material inserted into the metal pipe and pressed against the inner wall. FIG. 7 is a diagram illustrating how the reinforcing material of the example of FIG. 6 is inserted into the metal tube from the opening of the tube.

FIG. 1A shows a plan view of a fiber bundle fabric for producing a reinforcing material according to the present invention. The fiber bundle fabric 1 forming the reinforcing material is a plain weave fabric consisting of warp yarns 10 and weft yarns 20. The warp threads 10 each consist of a fiber bundle made up of a large number of chemical fibers, and the fiber bundles 10 constituting the warp threads are arranged in a horizontal row with their drawing direction Y parallel to each other, and are interconnected by weft threads 20. There is. As shown in FIG. 1(B), the weft yarns 20 pass between the warp yarns 10 every other fiber bundle 10 (every third in this embodiment) forming the warp yarns from the front to the back and from the back to the front. It is woven so that it moves and rises and falls, and has a structure in which every third fiber bundle 10 of the warp yarns is hingedly connected using the inter-warp passing portion 21 of the weft yarn as a joint. In this case, the warp fiber bundles 10 can also be glued together in groups of three.

As can be seen from FIGS. 1(A) and 1(B), the warp fiber bundles 10 are bundled into three bundles in this embodiment by the weft threads 20 which are tensioned by the above-described weaving method. These three pieces are fixed in close contact with each other. On the other hand, since the weft yarns 20 move to the front and back sides every three warps, the distance between the fiber bundles 10 corresponding to the inter-warp passing portions 21 of the weft yarns 20 that appear every three warps is, for example, about 0.1 mm to 1 mm. A gap exists depending on the material (or thickness) of the weft 20, and the gaps are separated. Therefore, the warp fiber bundle 10 is hinge-connected using the warp passing portion 21 as a joint, and as shown in FIG. 1(B), the fiber bundle fabric 1 bends using the warp passing portion 21 as a joint. Note that the inter-warp passing portion 21 of the weft 20 can be cut by inserting a blade such as a cutter into the gap between the warp yarns, and also functions as a section for separating the warp yarns 10. Such weft threads 20 can be made of polyethylene or polypropylene.

As shown in the cross-sectional view of FIG. 1(C) (one of the fiber bundles is shown), the fiber bundle 10 forming the warp is made of long-fiber high-strength fibers (each of which is stretched in the drawing direction Y). For example, it is formed by bundling a large number of aramid fibers 11 and impregnating and hardening them with a phenolic, polyester, epoxy, or acrylic resin. The thickness of one fiber bundle 10 made by bundling aramid fibers 11 is, for example, 500 decitex (dtex), and it is preferable to have a diameter of 0.5 mm or more and 5 mm or less, considering the strength for reinforcing. Further, the hardness of the impregnated resin is preferably 80 or less (Rockwell hardness) for processing the fiber bundle fabric 1.

The fiber bundle fabric 1 of the above configuration is rolled so that the stretching direction Y of the warp yarns 10 is the axial direction of the cylinder, that is, as shown in FIG. Use as. Since the warp threads 10 are hingedly connected at the warp passing 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 in FIG. 1(A) is shaped into a cylinder, the butted ends (left and right side edges in FIG. 1(A)) may be tied and connected using a binding material made of the same material as the weft yarns 20. . Alternatively, it is also possible to simply roll it into a cylindrical shape and leave the ends free without connecting them.

The fiber bundle fabric 1 shown in FIG. 2 rolled into a cylindrical shape has an adhesive layer formed on its outer surface. The adhesive layer can be formed, for example, 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 yarn 20. To form this adhesive layer, in this example, three warps 10 are grouped together to form one plate, so the adhesive is applied thickly to form a layer. This makes it easier to use, and it also makes it possible to increase the surface area of the adhesive layer.

3 and 4, a process for reinforcing a metal tube using the reinforcing material 100 after forming an adhesive layer on the cylindrical fiber bundle fabric 1 shown in FIG. 2 will be briefly illustrated and explained.

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

Since the reinforcing material 100 can be folded by folding at the warp passing portion 21, it is inserted into the metal tube P from the opening O in the folded and deflated state. The reinforcing material 100 illustrated in FIGS. 3 and 4 is shown in gray to indicate that an adhesive layer is formed on the outer surface. Although the weft yarn 20 is depicted in FIGS. 3 and 4, this is for illustrative purposes; the weft yarn 20 is actually covered with an adhesive layer.

The reinforcing material 100 inserted into the metal tube P unfolds (or is expanded) from the folded state, returns to the cylindrical shape shown in FIG. 2, and stands up inside the metal tube P. Then, a fluid solidifying material is injected from a pump into the inside of the standing reinforcing material 100 using a hose or the like, and the reinforcing material 100 is pushed against the inner wall of the metal tube P by spreading it out from the inside (FIG. 4). The fluid solidifying material is, for example, mortar, which solidifies after curing. When this fluid solidifying material is injected, since a plurality of warps 10 are bundled together as a set, there are few gaps where the fluid solidifying material leaks out of the reinforcing material 100, resulting in a structure that is difficult to leak.

Since 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 tube P is fixed to the metal tube P as the adhesive hardens, and is made of fiber bundles. The warp yarns 10 act as reinforcing members. Furthermore, the adhesive in the adhesive layer formed on the outer surface oozes out into the corrosion through holes opened in the tube wall due to corrosion, filling the corroded irregularities. Therefore, the corroded portions are reinforced and repaired from both the inside and outside of the metal pipe P.

In the case of metal pipes for installing electrical equipment such as road lighting, there is a hole for the power line in the underground part (the part inside the concrete in Figures 3 and 4), and the power line is drawn into the metal pipe through this hole. The inside of the metal tube is led to the electrical equipment mounted on the tip of the metal tube. When such internal parts such as electrical wiring are placed inside the metal tube, the fiber bundle fabric 1 is bent at the warp passing portion 21 as a joint, so this reinforcing material 100 is bent along the internal parts as shown in FIG. Can be transformed. That is, the reinforcing material 100 made of the fiber bundle fabric 1 shown in FIG. 5 is partially recessed inward along internal parts such as wiring pipes.

FIG. 6 shows a reinforcement example in which an opening O for inserting the reinforcing material 100 is newly formed in the metal tube P. The opening O is a new opening opened at the site to insert the reinforcing material 100, and is closed with a separately manufactured lid or the like after the reinforcing material is installed. The reinforcing material 100 is the same as that described above, but is made so that its axial length reaches above the opening O. That is, when the reinforcing material 100 is inserted into the metal tube P and stands up, the opening O is closed by the reinforcing material 100 from the inside. The reinforcing material 100 is provided with an injection port or an injection tube 30 to which a hose or the like is connected in order to inject the fluid solidifying material into a portion corresponding to the opening O, from which the fluid solidifying material is press-fitted. After injecting the solidifying material, the injection port or injection tube 30 is sealed. Alternatively, as another method, it is also possible to introduce a hose for injecting the solidifying material into the metal pipe P from above and inject the fluid solidifying material into the reinforcing material 100 from above.

The opening O becomes a defective part of the metal tube P, and if left as is, it may cause a decrease in strength, but since the defective part is covered and reinforced by the reinforcing material 100, the strength will not be impaired. , rather it is enhanced. With conventional thin sheet-like lining materials used for reinforcing metal pipes, when applied in the same manner as in this example, the lining material protrudes from the opening O due to the pressure of solidifying material injection, causing problems; As described above, in the reinforcing material 100 according to the invention, the warp threads 10 are fiber bundles of chemical fibers and have high strength, so that they can sufficiently resist the solidifying material injection pressure and do not curve and protrude from the opening O. .

In order to insert the reinforcing material 100 that is taller than the opening O in this example, as shown in FIG. 7, the reinforcing material 100 is first inserted upward from the opening O into the metal pipe P. Then, if the reinforcing material 100 is lowered once the entire reinforcing material 100 has entered the pipe, the raised state shown in FIG. 6 can be achieved. The steps other than this insertion procedure are as described with respect to the examples of FIGS. 3 and 4.

1 Fiber bundle fabric 10 Warp 11 Chemical fiber 20 Weft 21 Inter-warp passing portion 100 Reinforcing material P Metal tube O Opening

Claims (2)

A method for reinforcing metal pipes,
Inserting a cylindrical reinforcing material into a metal tube, injecting a fluid solidifying material inside the inserted reinforcing material and pressing the reinforcing material against the inner wall of the metal tube,
The reinforcing material is a plain-woven fiber bundle fabric consisting of warp yarns each consisting of a fiber bundle made up of a large number of chemical fibers, and weft yarns interconnecting the fiber bundles forming the warp yarns, wherein The weft threads are woven so as to pass between the warp threads every plurality of the warp threads and move up and down from the front to the back or vice versa , and the plurality of warp threads are fixed in close contact with each other, The fiber bundle fabric is made into a cylinder shape with the warp in the axial direction, and the warp is made bendable by hinge connection with the inter-warp passing portion of the weft at every plurality of warps as joints, and the cylindrical shape is A reinforcing method that uses a reinforcing material with an adhesive layer formed on its outer surface. A reinforcing material used for reinforcing metal pipes,
A plain weave fiber bundle fabric consisting of warp yarns each consisting of a fiber bundle made up of a large number of chemical fibers, and weft yarns interconnecting the fiber bundles forming the warp yarns, the weft yarns being arranged at intervals of a plurality of the warp yarns. The weave is woven so that it passes between the warp threads and moves from the front to the back or vice versa, rising and falling, and the plurality of warp threads are fixed in close contact with each other, and the warp threads are arranged every other warp thread. A fiber bundle fabric is made by forming a fiber bundle fabric into a cylindrical shape with the warp in the axial direction, in which the warp can be bent by hinge connection with the weft passing between the warp as a joint, and the adhesive layer is placed on the outside. A reinforcing material formed on the surface.