WO2008029794A1

WO2008029794A1 - Method of reinforcing existing structure with carbon fiber

Info

Publication number: WO2008029794A1
Application number: PCT/JP2007/067194
Authority: WO
Inventors: Yoshihiro Fukuda; Hideyuki Komaki; Masanori Nakata; Yasuhiro Mori; Junichi Kagawa; Kouichirou Tamuro; Shinya Enomoto
Original assignee: Nippon Oil Corporation; Konishi Co., Ltd.; Sg Engineering Co., Ltd.
Priority date: 2006-09-05
Filing date: 2007-09-04
Publication date: 2008-03-13
Also published as: JP2008063744A; TW200837262A

Abstract

A method of reinforcing an existing structure by winding a braid- or strip-form carbon-fiber-containing reinforcing material around the surface of the structure in a spiral or stripe arrangement at given intervals. A braid- or strip-form carbon-fiber-containing reinforcing material which has not been resin-impregnated is impregnated with a resin to obtain the reinforcing material. Namely, immediately before being wound around a structure, the braid- or strip-form carbon-fiber-containing reinforcing material which has not been resin-impregnated is passed through a resin tank filled with an impregnating resin. In particular, the resin tank is disposed in a portable device (1). The carbon fiber material is passed through the resin tank within the device and impregnated with the resin. The carbon fiber material (3') which has undergone resin impregnation is pulled out of the device and is wound as it is around the surface of an existing structure.

Description

Specification

Method for reinforcing existing structures with carbon fiber

Technical field

TECHNICAL FIELD [0001] The present invention relates to a method for reinforcing structures such as columns, beams, and chimneys using carbon fibers, and more particularly to a reinforcing method for enhancing the shear resistance or dust performance of a concrete structure. Background art

[0002] Concrete beams and columns, or existing concrete structures such as bridge piers and chimneys have strengths that differ greatly depending on the design standards at the time of construction, as well as a decrease in yield strength due to aging. In the previous Great Hanshin Awaji Earthquake, the new earthquake resistance standards were reviewed based on the experience that damage to buildings that met the standards of the new earthquake resistance design law enforced in 1981 was minor. Goods are also required to comply with the new seismic standards.

[0003] In the case of an existing structure, if it is demolished and newly constructed, a structure satisfying the new earthquake resistance standard can be obtained. However, the construction has a long period of time and the cost is great. Therefore, it is usually extremely deteriorated! / Unless otherwise, seismic reinforcement work is carried out.

[0004] As such seismic reinforcement work, a method of winding a steel plate around a concrete structure such as a column is known. However, since the weight of the steel sheet is large, it requires time-consuming equipment for construction, and there are problems with long-term durability such as the occurrence of rust.

On the other hand, from the viewpoint of being lightweight and having long-term durability, a reinforcing method using a reinforcing material using a reinforcing fiber sheet is known. For example, Fig. 7 shows a schematic diagram of the seismic reinforcement method for concrete columns. Figure 8 shows the flow sheet.

[0006] To ensure that the seismic reinforcement effect of the carbon fiber sheet (CF sheet) can be fully exerted, the protrusions and steps on the concrete surface should be removed and smoothed, and the corners should be rounded. Apply surface preparation (PS1) by sanding. Subsequently, in order to improve the adhesion of the CF sheet to the ground-treated concrete surface and the impregnation property of the impregnating resin to the carbon fiber sheet, a primer is applied to the ground-treated concrete surface (PS2). At this time, if necessary, unevenness adjustment processing with putty etc. is performed, but after applying primer, fingerprints do not get caught even with touch with an epoxy-based primer! /, Dry to touch, acrylic primer It is necessary to be in a fully cured state, even if you put up the hook! Continuing! /, Apply the resin to impregnate the CF sheet (PS3), paste the CF sheet (PS4), and then apply the impregnated resin on the CF sheet (PS5). Air bubbles contained in the CF sheet are removed (PS6). When pasting CF sheets in multiple layers, repeat undercoating, CF sheet pasting, topcoating, and defoaming. Thereafter, the resin is cured so that the impregnated resin is sufficiently cured.

[0007] In general, undercoating and overcoating of impregnating resin are performed using a brush or a roller.

Also, the CF sheet should be affixed with care so as not to leave a large amount of air bubbles and wrinkles that will cause insufficient adhesive strength, and it will be pressed into place with a defoaming roller or palm to bring it into close contact with the concrete. If air bubbles cannot be removed, a cut may be made in the fiber direction of the CF sheet to remove the air. In such a case, the resin is applied again to the cut. In addition, the top coat of the impregnated resin is applied to the surface of the CF sheet in the same way as when the surface of the undercoat impregnating resin has been lifted.

However, the method of applying the impregnating resin using a brush or a roller (so-called hand laying method) has a problem that a difference in uniformity is likely to occur depending on the skill of the operator. In addition, the CF sheet must be affixed with care so that bubbles and wrinkles do not occur, which also requires the skill of the operator.

[0009] In addition, in the case of full winding with a CF sheet, adjustment processing for steps, protrusions, unevenness, etc. is indispensable for obtaining sufficient adhesiveness, which complicates the process, increases costs, and increases the construction period. It is also a cause of prolonged periods.

[0010] For example, FIG. 9 shows the ground processing when there is a large step, and it is necessary to repair the upper part of the step by cutting it up and filling the lower part with mortar or the like so as to be continuous with the cut surface. . In addition, even for small steps due to differences in formwork, etc., after removing the shaving, the carbon fiber sheet is applied to the column surface by smoothing using epoxy-based putty after curing the finger-coated surface of the primer. It is said that it must be arranged to adhere.

[0011] Further, unlike the reinforcement by CF sheet, a method using a fiber reinforced resin composite material (FRP) molded in a predetermined shape is known. Since FRP is impregnated with resin in the manufacturing process, undercoating and overcoating of the impregnating resin at the work site are not required, but primer treatment is essential for bonding, and if there are protrusions etc. Same as CF sheet pasting In addition, ground processing is required. Furthermore, if there is a step, it is necessary to perform flattening that is much stronger than pasting a CF sheet, or prepare a molded product that matches the step shape. Therefore, the use of a molded product is poor in versatility as a method for reinforcing columns and the like.

[0012] In addition, when constructed by such a method, the concrete surface is covered with a reinforcing fiberboard after construction. For example, when a medium-scale earthquake occurs, cracking or the like occurs in the concrete. It is very difficult to diagnose whether it is! /, Na! /.

On the other hand, unlike the above-described full-surface reinforcement, a method of partially reinforcing is known.

For example, in Patent Document 1 (Japanese Patent Laid-Open No. Sho 62-244977) and Patent Document 2 (Japanese Patent Laid-Open No. Sho 62-2 42058), high-strength long fiber strands are used as seismic reinforcement methods for existing concrete columns. A method of winding in a spiral shape is shown. In these, there is a description that when a fiber filament is impregnated with a resin to form a strand, the resin is impregnated in advance or wound and then impregnated, but there is no detailed description.

[0014] Further, in Patent Document 3 (Japanese Patent Application Laid-Open No. 2002-115403), in order to reinforce a concrete column with a wall, a plurality of through holes are formed in the wall at intervals in the longitudinal direction of the column. It has been proposed to wind a bundle of reinforcing fiber strands around the outer periphery of the column through each through hole. There are two possible timings for impregnating the resin depending on the curing time of the resin. When using an impregnated adhesive resin with a relatively short curing time, when winding a bundle of reinforcing fiber strands, At the same time, when impregnating adhesive resin with a relatively long curing time is used, the bundle of reinforcing fiber strands is impregnated with the resin in advance, and then wound and pasted on site.

[0015] In the construction method using strands, the strands have to be wound several times to obtain the necessary amount of reinforcement, so that manual winding is rarely performed, and a dedicated winding machine is used. Since it is used, there is a problem that it is not versatile. When reinforcing with carbon fiber or other reinforcing fiber, the above-mentioned sheet method is simple to obtain the required amount of reinforcement, and is widely used because it can be constructed manually.

[0016] As described above, the method of applying the impregnating resin by the hand lay-up method has a problem that a difference in uniformity is likely to occur depending on the skill of the operator. In order to solve this problem, in Patent Document 4, a continuous fiber sheet impregnated with resin is used as a resin / fiber of 55/45 to 35 / Passing between two parallel rolls, the gap and compression force of which are adjusted to a weight ratio of 65, the uncured resin-impregnated continuous sheet of the weight ratio is formed as a single layer or multilayer on the outer surface of the structure. A method of reinforcing a structure that is wound or pasted is shown. Here, the impregnated sheet is rewound into a roll and is used after being pulled out on site. Therefore, it is necessary to take up carefully so as not to cause wrinkles or the like during rewinding. (Japanese Patent Laid-Open No. 6-288101), instead of the conventional sheet pasting method, a reinforcing fiber wound around a concrete structure is mixed with a thermoplastic resin and knitted into a long cloth. A method and apparatus for winding both sides of a long fabric-like reinforcing fiber and winding it around a concrete structure while dissolving the mixed resin are shown. This device is provided with a pair of rollers that rotate in contact with both the front and back surfaces of a long cloth, and a heating device is provided inside each roller. By using such an apparatus, it is said that the working time can be shortened as compared with the conventional sheet pasting method. However, this method is also based on the premise that it is wound around the entire surface of the reinforced body, and it is necessary to perform the ground treatment in the same way as before. In addition, this method uses a thermoplastic resin and cannot use thermosetting resins such as epoxy resins with excellent adhesive strength or room temperature curable resins such as epoxy adhesives. There is a problem of being inferior. Moreover, since the construction is performed while the thermoplastic resin is melted, the construction speed is not always sufficiently high. In addition, during construction, the resin will not melt completely or uneven melting will occur if the heating roller is installed before it reaches the specified temperature, or if it is applied at a speed higher than the specified speed, or if it is applied in winter. These may cause voids and poor adhesion.

Patent Document 1: JP-A 62-244977

Patent Document 2: Japanese Patent Laid-Open No. 62-242058

Patent Document 3: JP 2002-115403 A

Patent Document 4: Japanese Patent Laid-Open No. 2000-896

Patent Document 5: JP-A-6-288101

Disclosure of the invention Problems to be solved by the invention

[0018] The object of the present invention is that diagnosis after the occurrence of a medium-scale earthquake is easy, construction requires minimal ground treatment, and resin impregnation into reinforcing fibers can be easily and reliably performed.

It is to provide a reinforcing method that is easy to construct.

Means for solving the problem

[0019] The present inventors have developed a reinforcing method for winding a braided carbon fiber material or a band-shaped carbon fiber material in a striped or spiral manner with a predetermined interval as a new method to replace the continuous fiber reinforcing method. The braided carbon fiber material or belt-like carbon fiber material used in the present invention is the central part in brush coating or roller coating performed by the conventional continuous fiber method with a relatively large amount of carbon fiber. In some cases, the resin cannot be sufficiently impregnated. Therefore, in the present invention, a method is adopted in which the resin is impregnated by passing through a resin tank immediately before winding and wound as it is.

[0020] That is, the present invention is a method for reinforcing a braided or band-like carbon fiber-containing reinforcing material on a surface of an existing structure by spirally or stripedly winding the reinforcing material at a predetermined interval, and the braided shape is not impregnated with resin. Alternatively, when a band-like carbon fiber material is impregnated with a resin to make a reinforcing material, the braided or band-like carbon fiber material not impregnated with the resin is allowed to pass through a resin tank filled with the impregnation resin immediately before being wound around the structure. To the method.

[0021] In particular, in the present invention, the resin tank is included in a hand-held apparatus, and the carbon fiber material is impregnated with the resin through the resin tank in the apparatus, and the carbon fiber material after resin impregnation is used as the apparatus. It is preferable that the surface of the existing structure is applied as it is after it is pulled out from.

The invention's effect

[0022] In the present invention, carbon fiber material (hereinafter referred to as CF material) is impregnated with resin just before winding, so that the amount of carbon fiber is relatively large! / And braided or belt-like CF material can be sufficiently impregnated with resin. At the same time, construction is facilitated by a particularly hand-held device.

[0023] In addition, by performing winding at a predetermined interval, it is easy to diagnose after the occurrence of a medium-scale earthquake, and there is an effect that minimal ground processing is sufficient for construction. Brief Description of Drawings

[0024] FIG. 1 is a three-side view (front view (a), top view (b), side view (c)) showing an example of a resin impregnation apparatus used in the present invention.

FIG. 2 is a schematic diagram illustrating the inside of the apparatus of FIG. 1. (a) shows the roller arrangement when CF material is installed, and (b) shows the roller arrangement when resin impregnation.

FIG. 3 is a schematic view illustrating another embodiment of a resin impregnation method in a resin tank.

FIG. 4 is a schematic perspective view of a band-like carbon fiber material used in the present invention.

FIG. 5 is a schematic perspective view of a braided carbon fiber material used in the present invention.

6 is a diagram for explaining a construction method using the apparatus shown in FIG.

FIG. 7 is a schematic view showing a conventional reinforcing method using a carbon fiber sheet.

FIG. 8 is a flow sheet of a conventional reinforcing method using a carbon fiber sheet.

FIG. 9 is a diagram for explaining a background process (step process) in a conventional process.

Explanation of symbols

[0025] 1 Resin impregnation equipment

2 Handle

3 CF material

3 'CF material (resin impregnated)

4 Roll holding means

5 CF material outlet

6 Opening and closing part

7 Impregnating resin

8 Resin tank

9 Laura

10, 10 'impregnated roller

11, 11 'squeezing roller

12, 12 'direction regulating roller

13, 13 'discharge roller

14, 14, pressure roller 30 Band CF material

31 Warp (carbon fiber)

32 Weft

40 Braided CF material

51 RC¾

52 CFRP

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the CF material is impregnated with resin by passing it through a resin tank in which the impregnated resin is stored immediately before being wound around the structure to be reinforced. In particular, in the present invention, it is preferable to use a device that can be held by an operator for resin impregnation.

FIG. 1 is a three-side view (front view (a), top view (b), side view (c)) showing an example of a resin impregnation apparatus 1 usable in the present invention, and FIG. It is the schematic explaining an inside. This apparatus 1 includes means 4 for holding CF material 3 supplied in roll form, a resin tank 8 in which impregnated resin 7 is stored, CF material 3 is guided to resin tank 8, and resin tank 8 is It is equipped with various rollers that guide the CF material 3 'after passing to the CF material discharge port 5, and a handle 2 that can be held by hand. A part of the exterior (opening / closing part 6) is provided so that it can be freely opened and closed, and is configured so that it can be opened and CF material can be installed in the device. Also, maintenance of the internal device can be done by opening a part of the exterior.

[0028] A part of each roller included in the internal device is movable as shown in FIG. 2, facilitating installation of CF material in the device. In Fig. 2, (a) shows the roller arrangement when CF material is installed, and (b) shows the roller arrangement when resin is impregnated.

[0029] When CF material is installed in the apparatus, the tip part may be installed through the resin tank. However, a dummy tape or the like is provided at the tip part of the CF material and installed in the apparatus without passing through the resin tank. Then, the method of passing the CF material through the resin tank is preferable because it is simple and can be used without waste.

[0030] The rollers 10, 10 'are immersion rollers for immersing the CF material in the resin tank 8, and are positioned on the resin tank 8 when the CF material 3 is installed in the apparatus, and when immersed, the resin tank 8 has a mechanism to descend. In this example, two immersion rollers are provided with one force. It may also be 3 or more. The squeezing rollers 11, 11 ′ are facing each other with the CF material 3 ′ after passing through the resin tank 8, and when the CF material is installed, they are separated from each other. be able to. Thereafter, the CF member 3 ′ impregnated with resin is pulled out from the discharge portion 4 through the direction regulating rollers 12, 12 ′ and the discharge port rollers 13, 13 ′.

[0031] In this equipment, the CF material pulled out from the roll (especially the strip-shaped CF material) is transported in the horizontal direction within the equipment. To do so, it is necessary to twist the CF material at some stage. In the apparatus shown in FIGS. 1 and 2, the CF material discharge section 4 is configured to be rotatable so that a twist is applied in the apparatus. In this way, by applying a twist in the apparatus and controlling the CF member 3 ′ in the direction optimal for the attachment location, the attachment operation becomes easy.

[0032] When the CF material 3 is passed through the resin tank 8, in order to keep the impregnation state of the resin 7 constant, it is preferable to provide means for regulating the conveyance speed so that the conveyance speed of the CF material does not exceed a predetermined value. . It is preferable that such a conveyance speed regulating means can regulate at least the rotational speed of the squeezing rollers 11 and 11 ′. The conveyance speed of the CF material is not limited in general depending on the basis weight of the CF material and the viscosity of the impregnating resin, but may be a speed of about lm / min to 10 m / min.

[0033] Further, in order to improve the resin impregnation property, as shown in Fig. 3, a roller (14, 14 ') for applying pressure to the CF material against the immersion roller is provided in the resin tank. When the air inside is pushed out, the inside of the CF material becomes negative pressure and the impregnation of the resin increases.

[0034] The impregnating resin in the apparatus may be gelled over time and the resin impregnation property may be reduced. In the present invention, since the amount that can be filled in the apparatus that can be held is not so large, even if it gelates. It is possible to work within the pot life of the resin because it is not wasted and can be done quickly by improving workability.

[0035] The inside of the apparatus is provided with a releasable material so that the gelled resin can be easily removed, and the roller or the like is made of silicone rubber having excellent releasability. Is preferred.

[0036] <CF material> The band-like and braid-like CF materials preferably have a member width of 10 mm or more and 50 mm or less for V and displacement. The weight is preferably in the range of 10 g / m to 100 g / m. In particular, the present invention is effective when the basis weight of the carbon fiber is large. For example, while the basis weight of a conventional carbon fiber sheet used for full-surface reinforcement is about 300 g / m ^{2 due} to its construction method, the strip-like CF material used in the present invention is a conventional carbon fiber sheet. Even if the amount of carbon fiber is increased to more than ½00 g / m ² ), the resin can be sufficiently impregnated into the fiber.

[0037] 1. Strip CF material

As shown in FIG. 4, the belt-like CF material 30 is a cloth-like material in which a bundle of carbon fibers is oriented in one direction as warps 31 and bundled with wefts 32 such as polyethylene in order to suppress variation.

[0038] 2. Thread and string CF material

The “braid” is basically composed only of warp, and is different from “woven fabric” composed of warp and weft and “knitted fabric” composed of continuous loops. The braid used in the present invention (also called “string”) is manufactured by machine, and can be broadly divided into 8 strokes, 16 strokes, Kumago strikes, and many others. Classified as a string. Also, there are flat punching assembled into a flat shape and round punching assembled into a round shape. Fig. 5 shows a schematic diagram of braided CF material with 8 round punches.

[0039] 3. Reinforcing fiber

Carbon fiber is used as the reinforcing fiber to be used, but glass fiber, aramid fiber, other organic fibers, etc. can be mixed and used within the range without any problem, and can be appropriately selected according to the application. . The carbon fiber used is, for example, 2.45 X 10 ⁵ N / mm ^{2 for} the high-strength type and 4. 40 X 10 for the medium-elastic type in the tensile test method for carbon fiber reinforced plastic in accordance with JIS K 7073. ⁵ N / mm ^2, the high modulus type bow ^{6. 40 X 10 5 N / mm} 2 | using a material having a tension modulus of elasticity.

[0040] <Impregnated resin>

As the resin to be impregnated, a room temperature curing type or a thermosetting type epoxy resin, a thermosetting resin such as a polyester resin, or a radical reaction resin such as methyl metatalylate can be used. In particular, it is preferable to use a room temperature curing type epoxy resin, for example, Konishi ( Product name "Bond E2500" series, "CFB500" series, etc. made by Co., Ltd. can be used.

[0041] <Construction method>

First, the ground treatment of the construction part is performed. This surface treatment removes the decorative coating on the concrete surface, performs simple shaping of the concrete surface, rounding of the corners, repair of cracks, etc., and does not require high-level step processing. .

[0042] As described above, in order to improve the adhesion between the reinforcing member and the concrete, the reinforcing portion can be subjected to a primer treatment. As the primer, like the resin impregnated into the reinforcing member, a thermosetting adhesive agent such as an ordinary temperature curable or thermosetting epoxy resin or a polyester resin can be preferably used. For example, a primer such as “Bond E800” series manufactured by Konishi Co., Ltd. is preferable.

[0043] Next, the CF material passed just before the resin tank is wound around the concrete surface subjected to the primer treatment is wound at a predetermined interval. Fig. 6 is a schematic diagram showing the construction of the RC pillar 51 using the apparatus of the present invention. The operator holds the apparatus 1 in his hand and pulls out the CF material 3 'that has passed through the resin tank. Can be installed easily by turning around RC pillar 1. When the specified winding is done, cut CF material 3 'and continue to the next construction site.

[0044] After the CF material is wound, the carbon fiber resin reinforced material (CFRP) 52 is obtained by curing until the impregnated resin is sufficiently cured. Thereafter, in order to maintain the aesthetics of the surface and further improve the durability of the reinforcing member, finishing can be performed by applying a finishing mortar or spraying a paint or the like on the surface around which the reinforcing member is wound.

[0045] The CF material is wound at a predetermined interval. The winding interval varies depending on the required reinforcing effect and cannot be limited to a specific range. It is preferable to wind and reinforce the toughness reinforcement section with a predetermined interval so that the CF material is wound from the end of the column at the toughening interval (P) is 5 cm or more and P / D is 1/3 or less. . Further, since a larger amount of reinforcement is required for toughness reinforcement, it is preferable to wrap the CF member in layers.

[0046] On the other hand, since the shear reinforcement does not require the amount of reinforcement as much as the toughness reinforcement, the winding force S can be increased at a wider interval. Shear reinforcement covers the entire column, but usually it is toughness reinforcement. If it is often done in combination, it may be applied to the part other than the toughness reinforcement section. In addition, since the CF material used in the present invention has a large amount of carbon fiber, a sufficient amount of shear reinforcement can be obtained with a single winding.

[0047] The present invention is particularly effective in toughness reinforcement with a large amount of reinforcement.

[0048] The amount of toughness and shear reinforcement is, for example, the “Design and Construction Guidelines for Seismic Reinforcement Method of Railway Viaduct Columns Using Carbon Fiber Sheets” issued by the Railway Technical Research Institute.

You can choose to be designed on the safe side in accordance with the 3rd edition.

Claims

The scope of the claims

[1] A method of reinforcing a braided or band-like carbon fiber-containing reinforcing material on a surface of an existing structure by winding it in a spiral or striped manner at a predetermined interval, to a braided or band-like carbon fiber material not impregnated with resin When the reinforcing material is impregnated with the resin, the braided or band-like carbon fiber material not impregnated with the resin is passed through a resin tank filled with the impregnating resin immediately before being wound around the structure. Method.

[2] The resin tank is included in a hand-held apparatus, and the carbon fiber material is impregnated with resin through the resin tank in the apparatus, and the carbon fiber material after resin impregnation is pulled from the apparatus. The reinforcing method according to claim 1, wherein the surface of the existing structure is directly applied after being removed.

[3] The reinforcing method according to claim 1 or 2, wherein the braided or strip-like carbon fiber not impregnated with resin has a member width of 10 mm or more and 50 mm or less and a weight force of SlOg / m or more and 100 g / m or less. .