Method of repairing or reinforcing object

Abstract

To solve a problem that a method of reinforcing an object using a continuous fiber sheet requires a long construction time depending on the number of resin layers.SOLUTION: (a) A first resin composition 20 having a viscosity of less than 30 Pa*s is applied to an object 1 directly or via a base layer 10, (b) a reinforcing fiber 30 is placed on the first resin composition 20, (c) a second resin composition 40 having a viscosity of 30 Pa*s or more and 85 Pa*s or less is applied on the reinforcing fiber 30, (d) a photocurable resin sheet 50 is placed on the second resin composition 40, (e) the second resin composition is degassed by pushing it out from a top of the photocurable resin sheet 50, and (f) ultraviolet light is irradiated from a surface of the photocurable resin sheet 51 to cure the photocurable resin. The photocurable resin generates heat during the curing process. This heat promotes the curing of the resin compositions 20 and 40. Since steps (a) to (e) are performed nonstop, and step (f) also takes about 30 minutes, the construction time can be significantly reduced.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention is a method for repairing or reinforcing an object, and aims to reduce construction time by using a field impregnation method that uses a reinforcing fiber sheet (reinforcing fiber). [Background technology]

[0002] Patent Document 1 discloses a method for repairing or reinforcing an object using a reinforcing fiber sheet. The on-site impregnation method for the object involves impregnating reinforcing fibers on-site with a resin having a viscosity of less than 30 Pa·s. The resin generally used in the on-site impregnation method is a room temperature curing resin, but the curing time is several hours or more, so depending on the number of resin layers, a significant amount of construction time is required. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-143572 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, Patent Document 1 proposes a method in which a resin with a high viscosity of 30 to 85 Pa s is used as the resin to be impregnated into the fibers and the resin is impregnated into the fibers by applying pressure; however, the performance differs depending on whether the resin is uniformly impregnated into the reinforcing fiber sheet.

[0005] In the railway industry, including JR and private railways, reinforcement methods using carbon fiber sheets tend not to be chosen because installing carbon fiber sheets near overhead lines could cause electricity to flow, which could have a negative impact on railway facilities or lead to disasters such as fires.

[0006] This is a commonly used on-site impregnation method in which the reinforcing fibers are impregnated with a resin with a viscosity of less than 30 Pa·s, after which a photocurable resin sheet is attached directly or with the aid of a special resin, and then exposed to ultraviolet light, allowing construction to be completed quickly.

[0007] When a photocurable resin sheet is irradiated with ultraviolet light, heat is supplied to the resin during the curing process of the sheet, and the resin hardens more quickly. [Means for solving the problem]

[0008] The method for repairing or reinforcing an object includes the following steps (a) to (f).

[0009] (a) applying a first resin composition having a viscosity of less than 30 Pa s to an object directly or via a base layer; (b) disposing a reinforcing fiber on the first resin composition applied in (a) and impregnating the fiber; (c) applying a second resin composition having a viscosity of 30 Pa s or more and 85 Pa s or less onto the reinforcing fibers arranged in (b); (d) placing a photocurable resin sheet on the second resin composition applied in (c); (e) degassing the second resin composition by pushing it out from above the photocurable resin sheet; (f) Irradiating the surface of the photocurable resin sheet with ultraviolet light.

[0010] The method for repairing or reinforcing an object of the present disclosure further comprises: (g) A paint may be applied to the surface of the photocurable resin sheet.

[0011] The objects to be inspected include concrete, metal, and resin products. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram of an object after repair or reinforcement according to the first embodiment. [Diagram 2] 1 is a flowchart of a method for repairing or reinforcing an object according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Embodiment 1) The method for repairing or reinforcing an object according to the first embodiment will be described with reference to the drawings. Fig. 1 shows a schematic diagram of an object after repair or reinforcement according to the present embodiment, and Fig. 2 shows a flowchart of the repair or reinforcement method.

[0014] Each step will be described in detail below.

[0015] In this embodiment, the object to be repaired or reinforced is a structural member. The structural member may be concrete, metal, a resin product, etc. The object may be another structural member.

[0016] In step (a), first, the base layer 10 is applied to the concrete 1. A roller or the like is used for application. In the following, a roller or the like is used for application in the same manner. The base layer 10 is a resin dissolved in a solvent. The base layer 10 partially soaks into the inside of the concrete 1. The base layer 10 improves the adhesive strength of the resin compositions 20, 40, the reinforcing fiber 30, etc., which will be described later, to the concrete. Examples of the base layer 10 include Sinkbond Primer U-100 manufactured by Sekisui Chemical Co., Ltd. and Paste Primer V-000 manufactured by Sekisui Chemical Co., Ltd. Sinkbond Primer U-100 contains a urethane prepolymer as a resin and contains toluene and ethyl acetate as a solvent. Paste Primer V-000 contains a vinyl ester resin as a resin and contains styrene as a solvent. This base layer 10 may be called the 0th resin composition.

[0017] In step (a), the first resin composition 20 is further applied onto the base layer 10. The first resin composition 20 is an adhesive that is impregnated into the reinforcing fiber 30. A roller or the like is used for application. The first resin composition 20 may be applied directly onto the concrete 1 without using the base layer 10. The first resin composition 20 is liquid. The viscosity of the first resin composition 20 is less than 30 Pa·s. It is preferably 20 Pa·s or less. It is particularly preferably 5 Pa·s or less. The first resin composition 20 is a resin dissolved in a solvent. Examples of the resin include epoxy resin, epoxy acrylate resin, and unsaturated polyester. In this embodiment, the first resin composition 20 may be a bonding primer V-000 manufactured by Sekisui Chemical Co., Ltd. The bonding primer contains a vinyl ester resin.

[0018] In addition to the above resin, the first resin composition 20 may further contain a curing agent. For example, Mepox D manufactured by Sekisui Chemical Co., Ltd. is used as the curing agent. Mepox D mainly contains methyl ethyl ketone peroxide and dimethyl phthalate.

[0019] In step (b) following step (a), reinforcing fibers 30 are placed on the first resin composition 20. The reinforcing fibers 30 may be called a reinforcing fiber sheet. The reinforcing fibers 30 are, for example, carbon fibers. The carbon fibers may have a fiber diameter of 5 to 10 μm, and may be woven in different directions or woven in one direction.

[0020] Next, in step (c), a second resin composition 40 is applied onto the reinforcing fiber 30. The second resin composition 40 is an adhesive that bonds the reinforcing fiber 30 and the photocurable resin sheet 50. The second resin composition 40 is in a gel state. The viscosity of the second resin composition 40 is 30 Pa·s or more and 85 Pa·s or less. The second resin composition 40 is a resin dissolved in a solvent. Examples of the resin include an epoxy resin, an epoxy acrylate resin, and an unsaturated polyester. The second resin composition 40 may further contain a curing agent in addition to the above resin.

[0021] In step (d) following step (c), a photocurable resin sheet 50 is placed on the second resin composition 40. The photocurable resin sheet 50 is preferably one having insulation resistance. By using a photocurable resin sheet 50 having insulation resistance, the insulation of the entire reinforcement portion can be improved. As a sheet with high insulation properties, a photocurable resin sheet using an epoxy acrylate resin or the like is used.

[0022] In step (e) following step (d), a photocurable resin sheet 50 is placed and the second resin composition is degassed by pushing it out. A metal spatula, a plastic spatula, a degassing roller, or the like is used for degassing. By degassing, the base layer 10 and the reinforcing fibers 30, and the reinforcing fibers 30 and the photocurable resin sheet 50 are uniformly bonded. Degassing is also performed between the concrete 1 and the photocurable resin sheet 50.

[0023] In step (f) following step (e), ultraviolet light is irradiated from the surface of the photocurable resin sheet 50 to cure the photocurable resin. The photocurable resin generates heat during the curing process. This heat promotes the curing of the resin compositions 20, 40.

[0024] In step (g), after step (f), paint 60 may be further applied (painted) onto the photocurable resin sheet 50. The paint 60 is applied for the purpose of preventing deterioration due to ultraviolet rays contained in sunlight, decoration, etc.

[0025] After step (f) or (g), the resin compositions 20, 40, the reinforcing fibers 30, etc. are applied to the concrete 1, and the concrete 1 is left to stand, thereby hardening the resin compositions 20, 40.

[0026] Example 1 In Example 1, adhesive primer V-000 manufactured by Sekisui Chemical Co., Ltd. was used as the first resin composition 20. The adhesive primer V-000 has a viscosity of 0.2 Pa·s or less.

[0027] In Example 1, an adhesive strength test was performed on a test piece prepared according to the procedure of the first embodiment.

[0028] The test method complies with JIS A 6909. The test pieces were 300mm x 300mm in size and 60mm thick as specified in JIS A 5371. Nine attachments were attached to each piece using two of these test pieces, and adhesion tests were conducted on six pieces each day, three times a day, on the 1st, 3rd, and 7th days after construction. The tensile adhesion measuring device used was the R10000ND manufactured by Sanko Techno Co., Ltd. The test results are shown in Table 1. [Table 1]

[0029] The test results showed that the adhesive strength was approximately 3.0 (N / mm 2 ) and the target adhesive strength is 1.5 (N / mm 2 ), showing that its adhesive performance is high. In addition, steps (a) to (e) can be performed nonstop, and step (f) takes only about 30 minutes, showing that construction time can be significantly reduced. [Explanation of symbols]

[0030] 1. Concrete (object) 10 Base layer (No. 0 resin composition) 20 First resin composition 30 Reinforcing Fiber 40 Second resin composition 50 Photocurable resin sheet 60 paint

Claims

1. (a) applying a first resin composition having a viscosity of less than 30 Pa·s to an object directly or via a base layer; (b) arranging reinforcing fibers on the first resin composition applied in (a); (c) applying a second resin composition having a viscosity of 30 Pa·s or more and 85 Pa·s or less onto the reinforcing fibers arranged in (b); (d) placing a photocurable resin sheet on the second resin composition applied in (c); (e) degassing the second resin composition by pushing it out from above the photocurable resin sheet; (f) irradiating the surface of the photocurable resin sheet with ultraviolet light; Methods for repairing or strengthening objects.

2. The viscosity of the first resin composition is 20 Pa·S or less. A method for repairing or reinforcing an object according to claim 1.

3. The viscosity of the first resin composition is 5 Pa·S or less. A method for repairing or reinforcing an object according to claim 1.

4. moreover, (g) applying a coating material to the surface of the photocurable resin sheet; The method for repairing or reinforcing an object according to any one of claims 1 to 3, comprising the steps of:

5. The object is a concrete, metal or resin product. The method for repairing or reinforcing an object according to any one of claims 1 to 3.

6. The reinforcing fibers are glass fibers or carbon fibers. The method for repairing or reinforcing an object according to any one of claims 1 to 3.

7. The carbon fiber has a fiber diameter of 5 to 10 μm. The method for repairing or reinforcing an object according to claim 6.

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