JP2004131985A - Reinforcing prepreg sheet and the reinforcing method of concrete construction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing prepreg sheet and a reinforcing method of a concrete structure capable of developing an excellent characteristic as a reinforcing material of a metal mesh showing a strength in a short time and improving the workability. <P>SOLUTION: A prepreg sheet 10 that a reinforcing material made of metal mesh 1 such as steel or stainless steel is impregnated with a photo setting resin 2 is wound or stuck on/to the reinforcing face of the concrete structure. The prepreg sheet 10 is irradiated with light to harden. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reinforcing prepreg sheet and a method of reinforcing a concrete structure, and more particularly, to a method of attaching a prepreg sheet to a reinforcing surface and reinforcing the same.
[0002]
[Prior art]
For example, in the case of seismic strengthening of concrete structures such as reinforced concrete (RC) columns, the construction materials are limited due to the restrictions on construction time, construction range, material and heavy equipment access routes, etc. Is required.
[0003]
Under such a demand, the present applicant disclosed in Japanese Patent Application Laid-Open No. Hei 10-37485, a method of winding a metal mesh around a concrete structure and then impregnating a molten resin by spraying up or hand laying up to form a reinforced coating layer. We proposed a construction method.
[0004]
According to such a construction method, since the steel material constituting the metal mesh has excellent tensile strength, the shear strength of the RC member can be greatly improved. In addition, since the steel material has tensile toughness, it has the characteristic that it does not break immediately after the steel material yields, and therefore the buckling of the axial reinforcing bar is prevented by the effect of preventing the concrete from jumping out, so the bending deformation performance is increased. Can be improved.
[0005]
However, the above conventional method impregnates the metal mesh with molten resin by spray-up or hand lay-up at the construction site, so the time to strength development is long, and the workability is not good, so It does not completely satisfy the requirements.
[0006]
By the way, Japanese Patent Application Laid-Open No. 2000-2656680 discloses that a prepreg sheet impregnated with a light-curable resin in a light-transmitting reinforcing fiber is wound around a concrete structure such as an RC column, and the prepreg sheet is cured by light irradiation. A seismic reinforcement method for reinforcement is disclosed. According to this method, the prepreg sheet is quickly cured by irradiating light, so that the strength can be developed in a short time, and the material can be manufactured in a factory or the like and brought into the site, There is an advantage that workability is good.
[0007]
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following objects.
An object of the present invention is to provide a reinforcing prepreg sheet and a concrete structure capable of exhibiting strength in a short time and improving workability while taking advantage of the excellent properties of a metal mesh as a reinforcing material. It is to provide a reinforcing method.
[0008]
[Means for Solving the Problems]
The present inventor has conducted intensive studies to solve the above problems, and as a result, the metal mesh itself does not transmit light, but even a prepreg sheet made of a photocurable resin using the metal mesh as a reinforcing material, Since light is irregularly reflected around the mesh wire, it has been found that light can reach the back surface of the sheet and the resin can be cured.
[0009]
The present invention has been made based on the above findings, and employs the following means.
That is, the present invention resides in a reinforcing prepreg sheet obtained by impregnating a photocurable resin into a reinforcing material made of a metal mesh. A light-transmitting reinforcing fiber may be arranged on one side or both sides of the metal mesh to form a composite reinforcing material.
[0010]
Further, the present invention is characterized in that a prepreg sheet formed by impregnating a reinforcing material made of a metal mesh with a photocurable resin is wound or pasted on a reinforcing surface of a concrete structure, and the prepreg sheet is cured by light irradiation. The method of reinforcing a concrete structure is as follows. A prepreg sheet may be used in which a light-transmitting reinforcing fiber is disposed on one side or both sides of the metal mesh and used as a composite reinforcing material.
Furthermore, a prepreg sheet (first prepreg sheet) obtained by impregnating a reinforcing material made of a metal mesh with a photocurable resin, a metal mesh, and a light-transmitting reinforcing fiber disposed on one or both sides thereof. A prepreg sheet (a second prepreg sheet) obtained by impregnating a photo-curable resin into a reinforcing material is laminated on a reinforcing surface of a concrete structure and wound or attached to each of the first and second prepreg sheets. You may make it harden by light irradiation.
[0011]
Alternatively, a thermosetting resin sheet may be attached to one surface of the prepreg sheet to be integrated, and the thermosetting resin sheet side may be attached to a reinforcing surface of a concrete structure. After attaching the thermosetting resin sheet to the reinforcing surface of the concrete structure, the prepreg sheet may be attached to the thermosetting resin sheet surface.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of a prepreg sheet according to the present invention. The prepreg sheet 10 is formed by using the metal mesh 1 as a reinforcing material and impregnating the metal mesh 1 with a photocurable resin 2. FIG. 2 shows a prepreg sheet 10 according to a second embodiment, in which a reinforcing material is composed of a metal mesh 1 and a light-transmitting reinforcing fiber 3 disposed on one side thereof, and the reinforcing material is impregnated with a photocurable resin 2. Let it be a prepreg sheet. The light-transmitting reinforcing fibers 3 may be arranged not only on one side but also on both sides of the metal mesh 1. 1 and 2, reference numeral 4 indicates a protective film.
[0013]
Steel or stainless steel is used as a wire material of the metal mesh 1. The metal mesh 1 may be made of a wire made of a metal material that diffuses and reflects light, and aluminum or copper can be used in addition to steel. Steel is excellent in tensile strength and tensile toughness, and especially stainless steel. Steel is also suitable as the metal mesh 1 because it also has rust resistance. It is preferable that the metal mesh 1 has a wire diameter of 0.2 to 0.4 mm and a mesh number of 10 to 60.
[0014]
As shown in FIG. 3 (a), the metal mesh 1 may have a ratio a / b of the interval a between the vertical strands and the interval b between the horizontal strands of 1, but in the seismic reinforcement of the concrete structure, The tensile strength required for reinforcement has directionality. Therefore, while the strand spacing is increased in the direction where the tensile strength is required, the strand spacing is reduced in the direction perpendicular thereto, that is, as shown in FIG. It may be set to be less than.
[0015]
As the light-transmitting reinforcing fiber 3 in the prepreg sheet 10 of FIG. 2, glass fiber which is excellent in light transmission and strength and is inexpensive is used. Aramid fiber, acrylic fiber, transparent polyester fiber, polyethylene fiber, nylon fiber and the like can be used as the light-transmitting reinforcing fiber. One or a plurality of fibers may be used.
[0016]
Conventionally, an FRP prepreg sheet using glass fiber as a reinforcing material has glass short fibers arranged as chopped strand mats. On the other hand, in the present embodiment, since the tensile strength required for the reinforcement in the seismic retrofitting of the concrete structure has a directionality as described above, as shown in FIG. Are arranged uniaxially according to the direction required for reinforcement. Further, based on this arrangement, a three-axis arrangement as shown in FIG.
[0017]
As the photocurable resin 2, a resin material which is cured by a crosslinking reaction by ultraviolet rays is usually used, and may be selected from an unsaturated polyester resin, a phenol resin, an acrylic resin, a polyamide resin, an epoxy resin, an epoxy acrylate resin and the like. it can. As the photo-curing agent added to the resin, a photo-curing agent that absorbs ultraviolet light having a wavelength range of 365 to 410 nm is usually used. In addition, a photo-oxidizing agent, a curing assistant, a thickener, a filler, and the like are appropriately added to the resin as a regulator of curing characteristics and viscosity.
[0018]
FIG. 5 shows an example of using the prepreg to reinforce an RC column as a concrete structure. First, after a primer treatment is performed on the reinforcing surface of the RC column, the prepreg sheet 10 is wound while the protective film 4 on the back surface is peeled off. After the sheet 10 is wound, light is irradiated. Thereby, the photocurable resin is cured, and the RC columns are reinforced. At this time, the steel mesh itself does not transmit light, but diffusely reflects the light, so that the light reaches the back surface of the sheet and the entire resin is cured. After the sheet 10 is cured, the protective film 4 on the surface is peeled off. As a light source, an ultraviolet fluorescent lamp, a high-pressure mercury lamp, a metal halide lamp, or the like can be used, but it may be cured by sunlight. The prepreg sheet 10 can be formed into a plurality of turns according to the required strength.
[0019]
6 and 7 are cross-sectional views showing another embodiment. When the light transmission to the back surface of the prepreg sheet 10 is incomplete, the thermosetting resin sheet 11 may be interposed between the base material 50 of the concrete structure and the prepreg sheet 10. In this case, as shown in FIG. 6, the thermosetting resin sheet 11 may be attached to the back surface of the prepreg sheet 10 to be integrated with the base material 50. Alternatively, as shown in FIG. 7, the thermosetting resin sheet 11 may be pasted on the base material 50 in advance, and the prepreg sheet 10 may be pasted on the sheet 11. In addition, as the resin material of the thermosetting resin sheet, the above-listed resins to which no photocuring agent is added can be used.
[0020]
According to the above reinforcing method, the following advantages can be obtained.
Since a prepreg sheet made of a photocurable resin is used, it can be cured in a short time by irradiating light, and can exhibit 100% strength. As a result, for example, even in the case of reinforcement work on the site of a railway track, the strength is exhibited, so that it is safe to receive wind pressure of a train or the like on that day, and it is possible to perform split work. Also, since the sheet can be cut to any length and constructed, it is easy to carry out the material without the need for a heavy machine or the like.
[0021]
Since a steel mesh having excellent tensile strength is used as the reinforcing material, the shear strength of the RC member can be improved. In addition, since steel mesh has high tensile toughness and does not break immediately after it reaches yield, it can prevent buckling of the axial reinforcing bar by the effect of preventing concrete from jumping out and improve the bending deformation performance of RC members. Can be.
[0022]
Further, according to the prepreg sheet in which the reinforcing material is made of a composite material of steel mesh and glass fiber as shown in FIG. 2, the following advantages can be obtained.
In the case of a conventional FRP sheet using a carbon fiber, a glass fiber, or the like as a reinforcing material, the fiber ensures the bending deformation performance by forcibly restraining the axial reinforcing bar. In such a case, when the reinforcing material breaks, the strength of the RC member is suddenly lost.
[0023]
On the other hand, when the reinforcing material is a prepreg sheet made of a composite material of a steel mesh and a glass fiber, as shown in FIG. 8, the tensile properties have a shape that matches the properties of the glass fiber and the steel material. That is, even if the glass fiber breaks, the steel mesh is arranged, so that the glass fiber does not break immediately due to its tensile toughness. Therefore, even if the glass fiber breaks, the proof strength of the RC member does not suddenly decrease due to the steel mesh, and the RC member can be prevented from being broken.
[0024]
The first prepreg sheet (hereinafter, referred to as a steel mesh sheet) in which the reinforcing material is made of only a steel mesh shown in FIG. 1 and the second prepreg made of a composite material of a steel mesh and glass fiber shown in FIG. Prepreg sheets (hereinafter, composite sheets) can be used in combination. That is, the steel mesh sheet and the composite sheet may be laminated and wound around a concrete structure.
[0025]
In this case, by appropriately changing the combination of the steel mesh sheet and the composite sheet (for example, the number of turns in the case of winding and the number of sheets in the case of sticking), the ratio of the metal constituting the reinforcing layer, the glass fiber It is possible to change the ratio. As a result, for example, free combination is possible depending on the seismic reinforcement performance required for a pier or the like. In some cases, the combination may be partially changed with respect to the entire length of the pier.
[0026]
【The invention's effect】
As described above, according to the present invention, it is possible to develop the strength in a short time while improving the workability, while taking advantage of the excellent properties of the metal mesh as a reinforcing material.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a first embodiment of a prepreg sheet according to the present invention.
FIG. 2 is a sectional view showing a second embodiment.
FIG. 3 is a plan view showing an example of arrangement of strands in a metal mesh.
FIG. 4 is a plan view showing an example of fiber arrangement in glass fibers.
5A and 5B show an embodiment of a reinforcing method, wherein FIG. 5A is a front view, and FIG.
FIG. 6 is a sectional view showing another embodiment of the reinforcing method.
FIG. 7 is a sectional view showing another embodiment of the reinforcing method.
FIG. 8 is a view showing tensile properties of the prepreg sheet shown in FIG.
[Explanation of symbols]
1: Metal mesh (steel mesh)
2: Photo-curable resin 3: Light-transmitting reinforcing fiber (glass fiber)
4: protective film 10: prepreg sheet 11: thermosetting resin sheet

Claims (7)

A prepreg sheet for reinforcement made by impregnating a photocurable resin into a reinforcing material made of a metal mesh. A reinforcing prepreg sheet in which a photo-curable resin is impregnated into a reinforcing material composed of a metal mesh and light-transmitting reinforcing fibers disposed on one or both sides thereof. A prepreg sheet obtained by impregnating a reinforcing material made of a metal mesh with a photocurable resin is wound or pasted on a reinforcing surface of a concrete structure, and the prepreg sheet is cured by irradiating light to light. Reinforcement method. A metal mesh and a prepreg sheet obtained by impregnating a photocurable resin into a reinforcing material comprising a light-transmitting reinforcing fiber disposed on one side or both sides thereof are wound or pasted on the reinforcing surface of the concrete structure, A method for reinforcing a concrete structure, comprising irradiating a prepreg sheet with light to cure it. A first prepreg sheet obtained by impregnating a photo-curable resin into a reinforcing material made of a metal mesh, and a photo-curing material made of a metal mesh and a light-transmitting reinforcing fiber disposed on one or both sides thereof. A second prepreg sheet impregnated with a conductive resin is laminated on the reinforcing surface of the concrete structure, wound or attached, and each of the first and second prepreg sheets is cured by light irradiation. Method of reinforcing concrete structures. The concrete according to claim 3, 4 or 5, wherein a thermosetting resin sheet is attached to one surface of the prepreg sheet to be integrated, and the thermosetting resin sheet side is attached to a reinforcing surface of a concrete structure. How to reinforce structures. 6. The concrete structure according to claim 3, wherein the prepreg sheet is attached to the surface of the thermosetting resin sheet after the thermosetting resin sheet is attached to the reinforcing surface of the concrete structure. Reinforcement method.

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