JP2000034638A - Reinforcing sheet and reinforcing method of construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reinforcing sheet capable of improving the operability of conventional reinforcing method of construction and to provide a reinforcing method of construction. SOLUTION: This reinforcing sheet comprises a unidirectional sheet obtained by using a covering yarn obtained by spirally winding an organic yarn on a conducting wire being a core or a core yarn comprising the conducting wire being a core spun together with an organic yarn as a weft for a woven fabric and warps composed of an aramid yarn. The reinforcing sheet is wound on a structure, which is coated with a thermosetting resin, an electric current is sent to the conducting wire to generate heat. The resin is cured to reinforce the structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing sheet, and more particularly, it is wound around an existing concrete column or the like.
The present invention relates to a reinforcing sheet and a reinforcing method used in a method of applying a resin, curing the resin, and reinforcing the resin against earthquake.

[0002]

2. Description of the Related Art Conventionally, a seismic retrofitting method using carbon fiber or aramid fiber is to prepare a unidirectional sheet of the fiber and wind it around a structure such as a concrete column requiring reinforcement. A method of applying and impregnating a resin and leaving it to cure at room temperature is employed. The conventional construction method can use epoxy resin, vinyl ester resin, unsaturated polyester resin, phenol resin, etc. as thermosetting resin, but in terms of room temperature curing, it is practically limited to epoxy resin, and the number of days until curing is There is a disadvantage that it takes about 3 days to 1 week depending on the outside temperature, and the construction period is long.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a unidirectional sheet using aramid fibers to cure a thermosetting resin in a short time by the heat generated by energization. It is an object of the present invention to provide a method for reinforcing a structure aiming at improving the construction time and shortening the construction period, and a reinforcing sheet used therefor.

[0004]

Under such circumstances, the present inventors have conducted intensive studies and as a result, have found that a weft of a unidirectional sheet using aramid fiber (warp) is provided with a conducting wire as a core,
Using a covering yarn or a conducting wire wound around an organic fiber as a core, using a core yarn spun together with the organic fiber, attaching the unidirectional sheet to a structure, then applying and impregnating the sheet with a thermosetting resin, The inventors have found that if the current is supplied to the conductive wire and the thermosetting resin is cured in a short time by the heat generated by the current supply, the work period can be shortened, and the present invention has been completed.

That is, according to the present invention, a covering yarn in which a conducting wire is used as a core and an organic fiber is spirally wound or a core yarn which is used in a case where a conducting wire is used as a core and spun together with an organic fiber is used as the weft of a unidirectional sheet, and the warp is used as an aramid fiber The present invention provides a reinforcing sheet comprising a unidirectional sheet made of

Further, the present invention provides a method for manufacturing a semiconductor device comprising the steps of: winding the reinforcing sheet around a structure; applying the thermosetting resin to the reinforcing sheet; impregnating the reinforcing sheet with a thermosetting resin; And a reinforcing method for reinforcing a structure by curing the same.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the reinforcing sheet of the present invention,
The unidirectional sheet made of aramid fibers refers to a woven fabric using aramid fibers at least for the warp. As shown in FIG. 1, an outline of the appearance is a unidirectional woven fabric sheet 10 using aramid fibers for the warp yarns 1, and the warp yarns 1 are formed to pass in the left-right direction. In FIG. 1, the gap varies depending on the number of warp yarns per unit width. In addition, the weft 2 made of a conductive wire as a core and wound with an organic fiber or made of a conductive wire as a core and spun together with the organic fiber is a continuous yarn which is passed through in the up and down direction while knitting the warp yarn 1 and is coarsely formed side by side. Conductive wires connected to an energizing device not shown in the figure appear in the portions 3a and 3b. Aramid fibers used for warp are used to give strength. The aramid fiber is not particularly limited, but is preferably an aramid fiber having a tensile strength of 15 g / d or more and a Young's modulus of 500 g / d or more (d means denier). The number of twists of the aramid fiber is preferably as small as possible, and the number of twists is 5 to 50 times / m. If the number of twists increases, the Young's modulus of the sheet decreases, and the effect of shear reinforcement or bending reinforcement, which is the purpose of seismic reinforcement, decreases, which is not preferable. The basis weight of the unidirectional sheet is usually 200 to 1000 g / m ² , excluding the weight of the weft. The number of warp yarns per unit width is easily determined from the thickness of the aramid fiber used and the basis weight of the unidirectional sheet.

[0008] The conductor used for the weft is a good conductor metal,
Those having a large calorific value are preferable, and examples thereof include nickel-chromium alloy and iron-chromium alloy conductors. The diameter of the conductor is preferably in the range of 0.05 mm to 1.0 mm. If the diameter of the conductive wire is large, the diameter after winding the organic fiber described below becomes too large, which is not preferable.

As the weft, a covering yarn in which organic fibers are spirally wound around the above-mentioned conducting wire or a core yarn spun with organic fibers around the above-mentioned conducting wire is used. The conventional seismic retrofitting method using carbon fiber or aramid fiber sheets is a method of cutting these fiber sheets into fixed lengths, winding them around concrete columns that need reinforcement, bonding both ends together, and fixing them with epoxy resin. However, in the method of reinforcing a structure using a prepreg according to the present invention, a conductive wire is coated with an organic fiber having an insulating property in order to prevent a short circuit at a portion where the conductive wire overlaps when energized.

[0010] In a covering yarn in which a conductive wire is used as a core and organic fibers are spirally wound, the organic fibers are not particularly limited, and ordinary nylon, polyester, cotton, and aramid fibers can be used. The spiral winding density is not particularly limited, but may be 300 to 900 turns / m.
Degree, preferably 500 to 700 times / m. In addition, after the left spiral winding, the right spiral winding is further performed thereon, or vice versa, after the right spiral winding, the left spiral winding is further performed thereon. A so-called double covering yarn is preferred.

As the organic fibers used for producing the core yarn of the conductive wire, the same fibers as those used in the covering yarn can be used. The core yarn is formed by supplying a conductive wire to a front roller of a spinning machine, and spinning the core yarn with the core wire wrapped with organic fibers. Further, in order to prevent the fibers on the surface of the core yarn from fraying, the organic fibers may be further spirally wound around the outer layer of the core yarn.

In the unidirectional sheet made of the aramid fiber of the present invention, it is necessary to continuously form the wefts for energization. Therefore, as a loom for producing the unidirectional sheet, the wefts must be continuous. A shuttle loom that can be used is preferred.

The procedure for reinforcing a structure using the reinforcing sheet of the present invention is as follows. First, after winding the reinforcing sheet around the structure, the reinforcing sheet is impregnated with a thermosetting resin. Next, an electric current is applied to the conductive wire to generate heat,
The resin is cured to reinforce the structure. As a structure,
Not limited, civil engineering structures such as bridges, tanks and steel towers; road structures; rivers, harbors or marine structures; sites where strength is required, such as architectural structures. An existing concrete column or the like which is required is preferable. First, a primer is applied to the concrete surface in order to keep the reinforcing sheet of the present invention in close contact with the surface of the concrete column. Next, after winding the reinforcing sheet cut to a fixed length, the sheet is coated and impregnated with a thermosetting resin. In addition, further, another cut the reinforcing sheet is overlapped and wound on the already wound sheet,
The reinforcing sheet may be coated and impregnated with a thermosetting resin. By repeating the above operation several times, a reinforcing sheet of 1 to 3 layers is formed on the concrete surface.

The thermosetting resin applied to the reinforcing sheet includes a phenol resin, an epoxy resin, a polyurethane resin, an unsaturated polyester resin, a vinyl ester resin, and a polyimide resin. Epoxy resins and phenol resins are preferred from the viewpoint of cost and the like. The amount of resin applied to the reinforcing sheet of the present invention is 80 to 150%, preferably 100 to 140%, based on the reinforcing sheet. If the coating amount is small, the resin does not sufficiently penetrate into the fiber when heated, and a sufficient reinforcing effect cannot be obtained. If the coating amount is too large, the amount of resin used increases unnecessarily, which is uneconomical.

The reinforcing sheet wound on the concrete surface in one to three layers and coated with a thermosetting resin is supplied with a current through a lead wire extending from both ends of each reinforcing sheet to generate heat. To cure. Further, the required number of sheets may be wound by applying a primer on the cured sheet and repeating the same operation.

The heating holding temperature and the curing time by energization vary depending on the type of thermosetting resin to be used, the curing start temperature, and the like, and are appropriately determined according to the conditions at the time of use.

[0017]

Next, the present invention will be described in more detail with reference to examples, but this is merely an example and does not limit the present invention. Example 1 A 75 denier polyester fiber is wound around a nickel-chromium alloy wire having a wire diameter of 0.1 mm at a rate of 600 turns / m in a left spiral shape, and then further wound on the nickel chromium alloy wire in a right spiral shape.
By winding at a rate of 00 turns / m, a so-called double covering yarn was produced. The aramid fiber "Twaron HM" (manufactured by Akzo Nobel) having a denier of 3000 is used for the warp, and the double covering yarn is used for the weft. The basis weight is 415 g / m ² (excluding the weight of the weft).
The unidirectional sheet woven fabric was produced on a shuttle loom. In order to keep the produced unidirectional sheet in close contact with the surface of the concrete pillar, an epoxy resin-based primer was applied to the concrete surface, and then the reinforcing sheet cut to a fixed length was further wound. Next, a room-temperature curable epoxy resin was applied from above, and a current was applied to the conductive wires extending from both ends of the reinforcing sheet to generate heat, and the resin was cured at 80 ° C. for 2 hours. The amount of resin used is about 55
It was 0 g / m ² . Further, the tensile strength of the reinforcing sheet after curing of the resin was 60 ton-weight / m, and the elastic modulus was 10.3 ton-weight / mm ² .

Example 2 A core yarn spun using a 50 mm long staple fiber of aramid fiber "Twaron" (manufactured by Akzo Nobel Co., Ltd.) was prepared using a lead wire of an iron-chromium alloy having a wire diameter of 0.1 mm as a core. Further, a polyester fiber of 150 denier was spirally wound around the surface of the core yarn at a rate of 200 turns / m. Using 3000 denier fiber of aramid fiber "Twaron HM" (manufactured by Akzo Nobel) for the warp yarn,
The above-mentioned core yarn is used for the weft, and the basis weight is 415 g / m.
² A unidirectional sheet of woven fabric (excluding the weight of the weft) was produced on a shuttle loom. The procedure was performed in the same manner as in Example 1 except that the above-described unidirectional sheet was used. The amount of resin used was about 500 g / m ² . The tensile strength of the seismic retrofit sheet after curing of the resin is 61 tons / m, and the elastic modulus is 10.7.
Ton weight / mm ² .

Comparative Example 1 3000 denier fiber of aramid fiber "Twaron HM" (manufactured by Akzo Nobel) was used for the warp and 500 for the weft.
Using denier polyester fiber, weight per unit 415g
/ M ² unidirectional sheet woven fabric was made on a shuttle loom. In order to hold the produced unidirectional sheet in close contact with the surface of the concrete column, an epoxy resin-based primer was applied to the concrete surface, and then the unidirectional sheet cut to a fixed length was further wound. Next, a room temperature-curable epoxy resin was applied from above, and allowed to stand. It took about 3 days for complete curing. The amount of resin used is about 550g
/ M ² . The reinforcing sheet (FR
P) had a tensile strength of 60 ton-force / m and an elastic modulus of 10.5 ton-force / mm ² .

As is clear from the results of Examples 1 and 2 and Comparative Example 1, the time required for the hardening of each of the Examples was significantly longer than that of the conventional seismic retrofitting method using carbon fibers or aramid fibers. I was able to shorten it.

[0021]

According to the reinforcing sheet of the present invention, the amount of the applied thermosetting resin can be hardened in a short time by the heat generated by energization, and the construction period required for construction can be shortened. Further, the reinforcing sheet of the present invention is equivalent to those of the conventional method in physical properties such as tensile strength and elastic modulus.

[Brief description of the drawings]

FIG. 1 is a schematic view of a unidirectional sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Warp (aramid fiber) 2 Weft 3a, 3b Conductor 10 Unidirectional sheet

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[Procedure amendment]

[Submission date] September 2, 1998 (1998.9.2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 3

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) D03D 15/02 D03D 15/02 A 4L048 C E04C 5/07 E04C 5/07 E04G 23/02 E04G 23/02 F // C08L 61/06 C08L 61/06 63/00 63/00 Z 77/10 77/10 (72) Inventor Fumio Yamamoto 6-10-73 Minamitsukaguchicho, Amagasaki City, Hyogo Prefecture Shinto Paint Co., Ltd. (72) Inventor Masayuki Shimizu 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Inventor Takao Ota 2-5-2-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. F-term (reference) 2E164 AA01 AA05 BA01 2E176 AA04 BB03 BB29 4F100 AK33A AK47A AK53A BA01 DG12A DG18A DG19A DH01 EJ082 EJ422 EJ82A GB07 4J002 CC031 CD001 CL062 DA076 FD012 FD016 GL00 A04 AA04A25 A04 MA39

Claims (4)

[Claims] 1. A covering yarn in which a conductive wire is used as a core and organic fibers are spirally wound, or a core yarn which is used as a core and a conductive wire is used as a weft of a unidirectional sheet, and a warp yarn is made of an aramid fiber. A reinforcing sheet, comprising a conductive sheet. 2. The reinforcing sheet according to claim 1, wherein the conductor is a nickel-chromium alloy or iron-chromium alloy conductor. 3. The reinforcing sheet according to claim 1, wherein the thermosetting resin is an epoxy resin or a phenol resin. 4. After winding the reinforcing sheet according to any one of claims 1 to 3 around a structure, the reinforcing sheet is coated and impregnated with a thermosetting resin, and then a current is applied to the conductive wire. Reinforcement method of flowing, generating heat, curing resin, and reinforcing structures.