Reinforcement structure

Abstract

To improve the reinforcing effect of a concrete structure while reducing the number of laminated fiber sheets.SOLUTION: A reinforcing structure 10 has a reinforcing layer 12 in which a primer layer 20 and a resin mortar layer 50 are formed in this order on a surface 90A of a concrete structure 90, with a fiber sheet 40 including a reinforcing fiber 42 bonded to the resin mortar layer 50. A resin mortar 52 of the resin mortar layer 50 satisfies the following conditions (1) to (3): (1) Young's modulus should be 3000 N / mm2 or more; (2) Rupture strain should be 0.5% or more; (3) Shear bond strength should be 0.5 N / mm2 or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a reinforcing structure for concrete structures, particularly for unreinforced concrete structures.

Background Art

[0002] Currently, the aging of concrete structures in our country is progressing, and there are many structures that require immediate countermeasures. In particular, unreinforced concrete structures are inferior in seismic resistance compared to reinforced concrete structures, and are currently a structural form that is not newly constructed. However, since many unreinforced concrete structures such as railway facilities constructed mainly from the Taisho to the early Showa periods are still in use, their reinforcement and repair are urgent tasks.

[0003] Patent Document 1 discloses a reinforcing structure for a concrete structure in which a fiber sheet containing reinforcing fibers is adhered to the concrete structure with an adhesive such as an epoxy resin.

[0004] Non-Patent Document 1 also discloses the reinforcement of an unreinforced concrete beam using a CFRP grid made by arranging a plurality of reinforcing bars made of a carbon fiber composite material in a grid pattern and polymer cement mortar, and its effect.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the reinforcement method using a CFRP grid and polymer cement mortar, there was a problem that the amount of reinforcement with one layer of the CFRP grid was limited. For this reason, it is conceivable to use a fiber sheet having a larger amount of reinforcement per layer of the reinforcing material than the CFRP grid. However, in the conventional reinforcement structure in which the fiber sheet is adhered to a concrete structure with an adhesive such as an epoxy resin, there were the following problems. That is, in the conventional reinforcement structure in which the fiber sheet is adhered to a concrete structure with an adhesive such as an epoxy resin, it is designed based on the number of laminated sheets of the fiber sheet for the required amount of reinforcement. However, since the fiber sheet is expensive, there was a problem that the cost increases as the number of laminated sheets increases.

[0008] An object of the present invention is to improve the reinforcement effect of a concrete structure while reducing the number of laminated sheets of a fiber sheet.

Means for Solving the Problems

[0009] The reinforcement structure of the first aspect has a primer layer and a resin mortar layer formed in this order on the surface of a concrete structure, and a reinforcement layer in which a fiber sheet containing reinforcing fibers is adhered to the resin mortar layer. The resin mortar of the resin mortar layer satisfies the following conditions (1) to (3). (1) The Young's modulus is 3000 N / mm 2 or more (2) The breaking strain is 0.5% or more (3) The shear adhesion strength is 0.5 N / mm 2 or more

[0010] According to the reinforcement structure of the first aspect, since the resin mortar satisfies the above conditions (1) to (3), the cross-sectional rigidity of the resin mortar layer is improved, and the resin mortar layer is less likely to crack. For this reason, it is possible to perform a reinforcement design in consideration of not only the number of laminated sheets of the fiber sheet but also the cross-sectional rigidity of the resin mortar layer to which the fiber sheet is adhered. As a result, it is possible to improve the reinforcement effect of the concrete structure while reducing the number of laminated sheets of the fiber sheet.

[0011] In the reinforcing structure of the second aspect, in the reinforcing structure of the first aspect, the fiber sheet is adhered to the resin mortar layer by the resin mortar or the resin adhesive.

[0012] In the reinforcing structure of the third aspect, in the reinforcing structure of the first or second aspect, the ratio of the equivalent reinforcing bar of the reinforcing layer containing the resin mortar to the concrete structure is 0.1% or more.

[0013] In the reinforcing structure of the fourth aspect, in any one of the reinforcing structures of the first to third aspects, the thickness of the resin mortar layer is equal to or greater than the value obtained by multiplying the number of laminated sheets of the fiber sheet adhered with the resin mortar layer by 2.0 mm.

[0014] In the reinforcing structure of the fifth aspect, in any one of the reinforcing structures of the first to fourth aspects, the fiber sheet is disposed at a position where the distance from the surface of the reinforcing layer is shorter than the distance from the surface of the concrete structure.

[0015] In the reinforcing structure of the sixth aspect, in any one of the reinforcing structures of the first to fifth aspects, the fiber sheet is a fiber sheet in which a plurality of fiber-reinforced plastic wires including the reinforcing fibers are arranged in a herringbone pattern in the longitudinal direction and the wires are fixed to each other with a wire fixing material.

Advantages of the Invention

[0016] Since the present invention has the above configuration, it has an excellent effect that the reinforcing effect of the concrete structure can be improved while reducing the number of laminated sheets of the fiber sheet.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0018] Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings.

[0019] (Reinforcing Structure 10) The reinforcing structure 10 according to this embodiment will be described. FIG. 1 is a cross-sectional view showing the reinforcing structure 10 according to this embodiment.

[0020] The reinforcing structure 10 shown in FIG. 1 is a structure for reinforcing an unreinforced concrete structure 90, and suppresses peeling and the like of the unreinforced concrete structure 90. Examples of the unreinforced concrete structure 90 include, for example, water channels, lining walls of tunnels for railways and roads, buildings, bridges, and bridge piers. Note that the unreinforced concrete structure is not limited to the above structures, and any unreinforced concrete structure to be reinforced may be used. Further, the reinforcing structure of the present invention can also be applied to a reinforced concrete structure having reinforcing bars or the like inside.

[0021] Specifically, as shown in FIG. 1, the reinforcing structure 10 has a reinforcing layer 12 in which a primer layer 20 and a resin mortar layer 50 are formed in this order on the surface 90A of the unreinforced concrete structure 90. In the reinforcing layer 12, a fiber sheet 40 containing reinforcing fibers 42 is adhered to the resin mortar layer 50.

[0022] (Primer Layer 20) The primer layer 20 is formed by applying a primer to the surface 90A of the unreinforced concrete structure 90. The primer layer 20 has a function of enhancing the bondability (adhesiveness) between the unreinforced concrete structure 90 and the layer formed on the unreinforced concrete structure 90. As an example, a resin such as an epoxy resin is used as the primer for forming the primer layer 20. The primer is not limited to an epoxy resin, and may be, for example, a resin such as a thermosetting resin other than an epoxy resin, and various materials can be used.

[0023] (Fiber sheet 40) The fiber sheet 40 is a sheet material containing reinforcing fibers 42 and is a sheet material that functions to reinforce the unreinforced concrete structure 90. This fiber sheet 40 is disposed inside the resin mortar layer 50.

[0024] As the reinforcing fibers 42, for example, one or a plurality of organic fibers such as aramid, PBO (polyparaphenylene benzobisoxazole), polyamide, polyarylate, polyester, etc., metal fibers such as basalt fibers, carbon fibers, glass fibers, steel fibers, etc. can be mixed and used. Note that, as an example of the reinforcing fibers, it is not limited to these.

[0025] Specifically, as the fiber sheet 40, as shown in FIGS. 2(A) and (B), a plurality of fiber-reinforced plastic wire rods 43 containing reinforcing fibers 42 are aligned in a herringbone pattern in the longitudinal direction, and the wire rods 43 are fixed to each other with a wire fixing material 45 (so-called strand sheet) can be used. As shown in FIG. 2(B), the fiber-reinforced plastic wire rod 43 is formed by impregnating the reinforcing fibers 42 with a matrix resin 47 and curing the matrix resin 47.

[0026] Note that, as an example of the fiber sheet, it is not limited to the fiber sheet 40 shown in FIG. 2. As an example of the fiber sheet, for example, the fiber sheet 140 shown in FIG. 3 may be used, as long as it is a fiber sheet containing reinforcing fibers.

[0027] The fiber sheet 140 shown in FIG. 3 includes a fiber layer 144 in which reinforcing fibers 42 are arranged in one direction (the X direction in FIG. 3), and a support layer 146 that supports the fiber layer 144. The support layer 146 is disposed on one side of the fiber layer 144 and is composed of a mesh-shaped support sheet that supports the fiber layer 144. This support layer 146 suppresses the dispersion of the reinforcing fibers 42 of the fiber layer 144. Note that the support layer 146 may be disposed on both sides of the fiber layer 144, and a configuration without the support layer 146 may be adopted as long as the dispersion of the reinforcing fibers 42 is suppressed by some method.

[0028] Further, the fiber sheet 40 can also be a fiber sheet in which the reinforcing fibers 42 are arranged in one direction and impregnated with resin, and the resin is cured (so-called FRP plate). At this time, the resin impregnated into the fiber sheet can be a thermosetting resin such as a room temperature curing type or heat curing type epoxy resin, vinyl ester resin, acrylic resin, unsaturated polyester resin, phenolic resin, or a thermoplastic resin such as an in-situ polymerizable phenoxy resin, nylon, or vinylon. Preferably, an epoxy resin which is a thermosetting resin is used. Also, the resin impregnation amount in the fiber sheet 40 is 30 to 70% by weight, preferably 40 to 60% by weight.

[0029] (Resin mortar layer 50) The resin mortar layer 50 is a layer to which the fiber sheet 40 is adhered and also has a function of reinforcing the unreinforced concrete structure 90. The resin mortar layer 50 is formed, for example, by applying (undercoating) the uncured resin mortar 52 to the unreinforced concrete structure 90 on which the primer layer 20 is formed, attaching the fiber sheet 40 to the resin mortar 52, further applying (topcoating) the uncured resin mortar 52 onto the fiber sheet 40, and curing the resin mortar 52.

[0030] The resin mortar 52 of the resin mortar layer 50 satisfies the following conditions (1) to (3). (1) The Young's modulus is 3000 N / mm 2 or more (2) The breaking strain is 0.5% or more (3) The shear adhesion strength is 0.5 N / mm 2 or more

[0031] If the Young's modulus of the resin mortar 52 is less than 3000 N / mm 2 in order to obtain the cross-sectional rigidity of the resin mortar layer 50, the resin mortar must be thickly coated. From the viewpoint of improving the cross-sectional rigidity of the resin mortar layer 50, the Young's modulus of the resin mortar 52 is preferably 4000 N / mm 2 or more, and more preferably 5000 N / mm 2 or more

[0032] Also, although there is no particular regulation on the upper limit of the Young's modulus of the resin mortar 52 as long as the fracture strain and the shear adhesion strength satisfy the specified numerical values, in order to ensure the joint strength, it is preferably approximately 15000 N / mm 2 or less. The Young's modulus is a value measured by a method conforming to JIS-K7161

[0033] If the fracture strain of the resin mortar 52 is less than 0.5%, cracks are likely to occur in the resin mortar layer 50. When the fracture strain of the resin mortar 52 is less than 0.5%, in particular, cracks in the resin mortar layer 50 are a concern before the peeling of the fiber sheet 40 from the reinforced concrete structure 90 occurs. The fracture strain is the strain when the resin mortar 52 breaks

[0034] From the viewpoint of suppressing cracks in the resin mortar layer 50, the fracture strain of the resin mortar 52 is preferably 1.0% or more, and more preferably 1.5% or more. Also, although there is no particular regulation on the upper limit of the fracture strain of the resin mortar 52 as long as it satisfies the specified numerical values of the Young's modulus and the shear adhesion strength, it is preferably approximately 5.0% or less. The fracture strain is a value measured by a method conforming to JIS-K7161

[0035] The shear adhesion strength of the resin mortar 52 is 0.5 N / mm 2If it is less than this value, the resin mortar 52 is likely to crack. When the shear adhesion strength of the resin mortar 52 is less than 0.5 N / mm 2 If it is less than this value, in particular, before the peeling of the fiber sheet 40 from the reinforced concrete structure 90 occurs, cracking of the resin mortar layer 50 is a concern.

[0036] From the viewpoint of suppressing cracking of the resin mortar layer 50, the shear adhesion strength of the resin mortar 52 is preferably 1.0 N / mm 2 or more, and more preferably 1.5 N / mm 2 or more. The shear adhesion strength is a value measured by a method compliant with JSCE - 543 - 2012 "Adhesion Strength Test between Continuous Fiber Sheet and Concrete" specified by the Japan Society of Civil Engineers.

[0037] As the resin mortar satisfying the above conditions, for example, C1S (epoxy resin mortar manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) is used.

[0038] The resin used as a binder in the resin mortar is preferably a liquid thermosetting resin capable of room - temperature curing, such as epoxy resin, acrylic resin, vinyl ester resin, unsaturated polyester resin, polyurethane resin, and polyurea resin, and epoxy resin is particularly preferably used. As the epoxy resin, bisphenol A type epoxy resin or bisphenol F type epoxy resin can be preferably used. The epoxy resin curing agent is not particularly limited as long as it reacts and cures with the epoxy resin at room temperature, but polyamine - based curing agents are preferred, and aliphatic polyamines or their modified products are particularly preferably used. The curing agent is compounded in an amount of 20 - 70 parts by weight, preferably 30 - 60 parts by weight, per 100 parts by weight of the epoxy resin.

[0039] Regarding the aggregates, fine aggregates such as silica sand, mountain sand, river sand, and sea sand that have been conventionally used, oxide-based ceramics such as alumina and silica, carbide-based ceramics such as silicon carbide and boron carbide, other fine ceramics, porcelain crushed materials such as mullite, and strip-shaped or short fiber-shaped reinforcing fibers can also be used, and a plurality of these types can be combined and used. The particle size of the aggregates is preferably fine ones of 1000 μm or less (mesh size 16), and more preferably ones of 75 μm or less (mesh size 200).

[0040] The amount of aggregates relative to the binder is 50 to 300 parts by weight, preferably 100 to 200 parts by weight, per 100 parts by weight of the binder. If the amount of aggregates is less than 50 parts by weight, the strength of the resin mortar required for reinforcement cannot be obtained. If it exceeds 300 parts by weight, the fluidity of the resin mortar due to the excessive amount of aggregates decreases, leading to insufficient impregnation of the fiber sheet and deterioration of workability. In addition, the resin mortar can contain 0.1 to 8 parts by weight of other additives such as silane coupling agents, viscosity modifiers, and colorants for the purpose of improving the affinity between the aggregates and the resin.

[0041] The thickness of the resin mortar layer 50 is preferably a value equal to or greater than the product of 2.0 mm and the number of laminated sheets of the fiber sheet 40 adhered by the resin mortar layer 50. Therefore, for example, when the number of laminated sheets of the fiber sheet 40 adhered by the resin mortar layer 50 is 2, the thickness of the resin mortar layer 50 is preferably 4.0 mm (2 × 2.0 mm) or more. Also, for example, when the number of laminated sheets of the fiber sheet 40 adhered by the resin mortar layer 50 is 3, the thickness of the resin mortar layer 50 is preferably 6.0 mm (3 × 2.0 mm) or more.

[0042] If the thickness of the resin mortar layer 50 is less than the value obtained by multiplying the number of laminated fiber sheets 40 by 2.0 mm, the cross-sectional rigidity of the resin mortar layer 50 will decrease. From the viewpoint of improving the cross-sectional rigidity of the resin mortar layer 50, the above value is preferably 2 mm or more, and more preferably 5 mm or more. Furthermore, from the viewpoints of economy, the number of laminated layers, and the cross-sectional rigidity, the above value is preferably 30 mm or less.

[0043] (Other conditions for the reinforcing layer 12) The reinforcing bar ratio of the reinforcing layer 12 containing the resin mortar 52 to the unreinforced concrete structure 90 in terms of steel is preferably 0.1% or more.

[0044] If the reinforcing bar ratio in steel equivalent is less than 0.1%, the fiber sheet 40 is likely to break and peel when cracks occur in the unreinforced concrete structure 90. From the viewpoint of suppressing breakage and peeling of the fiber sheet 40, the reinforcing bar ratio in steel equivalent is preferably 0.2% or more, and more preferably 0.5% or more.

[0045] Furthermore, although there is no specific upper limit for the steel equivalent reinforcement ratio, a higher reinforcement ratio requires a larger amount of reinforcing sheet, so from an economical point of view it is set to 1.0% or less.

[0046] The reinforcing bar ratio in steel equivalent is a value calculated using the following formula 1.

[0047]

number

[0048] The "Young's modulus of the reinforcing layer" in the above formula 1 is a value calculated from the following formula 2.

[0049]

number

[0050] The interfacial debonding fracture energy (Gf) of the fiber sheet 40 is preferably 0.5 N / mm or more. If the interfacial debonding fracture energy is less than 0.5 N / mm, the fiber sheet 40 is likely to peel off. From the viewpoint of suppressing the peeling of the fiber sheet 40, the interfacial debonding fracture energy is preferably 0.5 N / mm or more, and more preferably 0.9 N / mm or more. The interfacial debonding fracture energy is a value measured by a method conforming to JSCE-543-2012 "Adhesion Strength Test between Continuous Fiber Sheet and Concrete" specified by the Japan Society of Civil Engineers.

[0051] As shown in FIG. 4, the fiber sheet 40 is preferably disposed at a position where the distance L2 from the surface 12A of the reinforcing layer 12 is shorter than the distance L1 from the surface 90A of the non-reinforced concrete structure 90. The surface 12A of the reinforcing layer 12 is the surface on the side opposite to the surface 90A side of the non-reinforced concrete structure 90 in the reinforcing layer 12.

[0052] Specifically, the fiber sheet 40 is preferably disposed at a position where the distance L1 from the surface 90A of the non-reinforced concrete structure 90 and the distance L2 from the surface 12A of the reinforcing layer 12 satisfy L1≧L2. The smaller the distance L1 (closer to the surface 90A of the non-reinforced concrete structure 90), the lower the reinforcing effect of the fiber sheet 40. Also, the distance L2 is preferably 0 mm or more.

[0053] The arrangement position of the fiber sheet 40 in the resin mortar layer 50 is adjusted, for example, by attaching the fiber sheet 40 to the resin mortar 52 as follows. That is, after arranging a spacer for defining the distance from the surface 90A of the non-reinforced concrete structure 90 with respect to the resin mortar 52 before curing applied to the non-reinforced concrete structure 90, the fiber sheet 40 is positioned with the spacer and then attached to the resin mortar 52.

[0054] In addition, as the reinforcing structure 10, a configuration in which the distance L2 is longer than the distance L1 (L2 > L1), or a configuration in which the distance L1 and the distance L2 are the same may be used. Further, a configuration in which the fiber sheet 40 is attached to the surface of the resin mortar layer 50 (L2 = 0 mm) may be used. In this case, the resin mortar 52 is not applied on the fiber sheet 40. When a plurality of fiber sheets 40 are used, it is preferable that all of them are arranged at positions where L1 ≥ L2, but a part of the plurality of fiber sheets 40 may be arranged at positions where L1 ≥ L2. That is, at least a part of the plurality of fiber sheets 40 may be arranged at positions where L1 ≥ L2.

[0055] (Modification example of the reinforcing layer 12) The reinforcing layer 12 includes the primer layer 20 and the resin mortar layer 50, but may further include another layer.

[0056] Examples of the another layer include a layer made of a surface irregularity correcting material. The surface irregularity correcting material is applied, for example, to the surface of the primer layer 20. The surface irregularity correcting material has a function of smoothing the unevenness on the surface of the unreinforced concrete structure 90. As an example, a resin such as an epoxy resin is used for the surface irregularity correcting material. Note that the surface irregularity correcting material may be a resin such as a thermosetting resin other than the epoxy resin, and various materials can be used.

[0057] In addition, examples of the another layer include a protective layer. The protective layer is formed, for example, on the surface of the resin mortar layer 50 as a layer that protects the resin mortar layer 50 from deterioration due to ultraviolet rays, exhaust gas, etc.

[0058] Furthermore, a resin adhesive may be used for attaching the fiber sheet 40. Particularly when the fiber sheet 40 is the fiber sheet 140 shown in FIG. 3, it is preferably used because it is difficult to impregnate and bond with resin mortar. Note that as the resin adhesive, a room temperature curing type epoxy resin, an epoxy acrylate resin, an acrylic resin, an MMA resin, a vinyl ester resin, an unsaturated polyester resin, or a photo-curing type resin is used, and a room temperature curing type epoxy resin is preferably used.

[0059] When a resin adhesive is used for attaching the fiber sheet 40, for example, with respect to the unreinforced concrete structure 90 having the primer layer 20 formed thereon, the fiber sheet 40 is adhered with the resin adhesive, and the uncured resin mortar 52 is applied onto the fiber sheet 40 to form the resin mortar layer 50. Also, with respect to the surface of the resin mortar layer 50 formed on the unreinforced concrete structure 90 having the primer layer 20 formed thereon, the fiber sheet 40 is adhered with the resin adhesive, and the uncured resin mortar 52 is applied onto the fiber sheet 40 to further form the resin mortar layer 50. Further, with respect to the surface of the resin mortar layer 50 formed on the unreinforced concrete structure 90 having the primer layer 20 formed thereon, a configuration (L2 = 0 mm) of adhering the fiber sheet 40 with the resin adhesive is conceivable.

[0060] (Effects of the present embodiment) The effects of the present embodiment will be described.

[0061] In the reinforcement structure 10, the resin mortar 52 of the resin mortar layer 50 satisfies the following conditions (1) to (3). (1) The Young's modulus is 3000 N / mm 2 or more (2) The fracture strain is 0.5% or more (3) The shear adhesion strength is 0.5 N / mm 2 or more

[0062] Therefore, the cross-sectional rigidity of the resin mortar layer 50 is improved, and cracks are less likely to occur in the resin mortar layer 50. For this reason, it is possible to perform a reinforcement design in consideration of not only the number of laminated sheets of the fiber sheet 40 but also the cross-sectional rigidity of the resin mortar layer 50 that adheres the fiber sheet 40. As a result, while reducing the number of laminated sheets of the fiber sheet 40, the reinforcement effect of the unreinforced concrete structure 90 can be improved.

[0063] In the reinforcement structure 10, it is preferable that the ratio of the reinforcing bars in terms of steel bars of the fiber sheet 40 to the unreinforced concrete structure 90 is 0.1% or more. When the ratio of the reinforcing bars in terms of steel bars is 0.1% or more, breakage and peeling are less likely to occur in the fiber sheet 40 when the unreinforced concrete structure 90 cracks. As a result, while reducing the number of laminated sheets of the fiber sheet 40, the reinforcing effect of the unreinforced concrete structure 90 can be further improved.

[0064] In the reinforcement structure 10, it is preferable that the thickness of the resin mortar layer 50 is equal to or greater than the value obtained by multiplying the number of laminated sheets of the fiber sheet 40 by 2.0 mm. When the thickness of the resin mortar layer 50 is equal to or greater than the said value, the cross-sectional rigidity of the resin mortar layer 50 is improved. As a result, while reducing the number of laminated sheets of the fiber sheet 40, the reinforcing effect of the unreinforced concrete structure 90 can be further improved.

[0065] In the reinforcement structure 10, it is preferable that the fiber sheet 40 is arranged at a position where the distance L2 from the surface 12A of the reinforcement layer 12 is shorter than the distance L1 from the surface 90A of the unreinforced concrete structure 90. When the fiber sheet 40 is arranged at a position where the distance L2 is shorter than the distance L1, the effective height increases, so the reinforcing effect by the fiber sheet 40 is improved. As a result, while reducing the number of laminated sheets of the fiber sheet 40, the reinforcing effect of the unreinforced concrete structure 90 can be further improved.

[0066] In the reinforcement structure 10, as the fiber sheet 40, a plurality of fiber-reinforced plastic wire rods containing reinforcing fibers 42 are aligned in a zigzag shape in the longitudinal direction, and a fiber sheet (so-called strand sheet, see Fig. 2) in which the wire rods are fixed to each other with a wire fixing material is used. Since the said strand sheet has a high reinforcing effect, while reducing the number of laminated sheets of the fiber sheet 40, the reinforcing effect of the unreinforced concrete structure 90 can be further improved.

[0067] (Evaluation test) In this test, the reinforcement effect of the unreinforced concrete structure 90 in the reinforcement structure 10 according to this embodiment was evaluated. Specifically, in this test, for Example 1 and Comparative Example 1, the evaluation was carried out as follows.

[0068] [Example 1] Resin mortar 52 Type: Epoxy resin mortar (Product name: C1S (manufactured by Nippon Steel Chemical & Material)) Young's modulus: 5580 N / mm 2 Breaking strain: 1.6% Shear adhesion strength: 1.513 N / mm 2 Coating range: Adhesion length 2100 mm, adhesion width 150 mm Thickness: 2 mm and 7 mm

[0069] [Comparative Example 1] Instead of resin mortar, the following adhesive was used. Adhesive type: Epoxy resin (Product name: E7S (manufactured by Nippon Steel Chemical & Material)) Young's modulus: 2730 N / mm 2 Breaking strain: 2.1% Shear adhesion strength: 1.5 N / mm 2 Coating range: Adhesion length 2100 mm, adhesion width 150 mm Thickness: 2 mm and 7 mm

[0070] [Common conditions] Fiber sheet 40: Carbon fiber strand sheet (designed thickness 0.333 mm, width 125 mm, length 2100 mm, number of laminated sheets 1) Reinforcement ratio of steel bar equivalent of resin fiber sheet 40 to unreinforced concrete structure 90: 0.15 - 0.22% Test specimen: Unreinforced concrete with width 150 mm, height 250 mm, and length 2650 mm Test: Bending test with two-point incremental load with a span length of 2250 mm and a pure bending section of 450 mm

[0071] Using the analysis model under the above test conditions, the "load - mid - span deflection (see Figure 5)" was calculated.

[0072] [Results of reinforcement effect] Under the condition that the thickness of the resin mortar of Example 1 and the adhesive of Comparative Example 1 was 2 mm, when using the resin mortar of Example 1 (see A3) compared with using the adhesive of Comparative Example 1 (see A4), the cracking load (endurance) (see point M in Figure 5) and the ultimate load (endurance) were improved.

[0073] Under the condition that the thickness of the resin mortar of Example 1 and the adhesive of Comparative Example 1 was 7 mm, when using the resin mortar of Example 1 (see A1) compared with using the adhesive of Comparative Example 1 (see A2), the cracking load (endurance) (see point M in Figure 5) and the ultimate load (endurance) were improved.

[0074] Also, compared with the condition where the thickness was 2 mm, in the case of the condition where the thickness was 7 mm, the load improvement rate of the resin mortar of Example 1 with respect to the adhesive of Comparative Example 1 was higher.

[0075] As described above, when using the resin mortar of Example 1 compared with using the adhesive of Comparative Example 1, the post - cracking endurance and the ultimate endurance of the unreinforced concrete structure 90 are improved. That is, the reinforcement effect of the resin mortar of Example 1 is higher compared with using the adhesive of Comparative Example 1.

[0076] The present invention is not limited to the above - described embodiments, and various modifications, changes, and improvements are possible within the scope without departing from the gist thereof.

Explanation of reference numerals

[0077] 10 Reinforcement structure 12 Reinforcement layer 12A Surface 20 Primer layer 40 Fiber sheet 42 Reinforcing fiber 43 Fiber - reinforced plastic wire 45 Wire fixing material 47 Matrix resin 50 Resin mortar layer 52 Resin mortar 90 Reinforcement-free concrete structure 90A Surface 140 Fiber sheet 144 Fiber layer 146 Support layer L1 Distance L2 Distance

Claims

1. It has a reinforcing layer in which a primer layer and a resin mortar layer are formed in this order on the surface of a concrete structure, and a fiber sheet containing reinforcing fibers is adhered to the resin mortar layer. The resin mortar of the resin mortar layer satisfies the following conditions (1) to (3). The thickness of the resin mortar layer is equal to or greater than the value obtained by multiplying the number of laminated sheets of the fiber sheet adhered with the resin mortar layer by 2.0 mm. A reinforcing structure for a concrete structure. (1) The Young's modulus is 3000 N / mm ２ or more (2) The breaking strain is 0.5% or more. (3) The shear adhesion strength is 0.5 N / mm ２ or more

2. It has a reinforcing layer in which a primer layer and a resin mortar layer are formed in this order on the surface of a concrete structure, and a fiber sheet containing reinforcing fibers is adhered to the resin mortar layer. The resin mortar of the resin mortar layer satisfies the following conditions (1) to (3). The steel bar equivalent reinforcing bar ratio of the reinforcing layer containing the resin mortar with respect to the concrete structure is 0.1% or more. A reinforcing structure for a concrete structure. (1) The Young's modulus is 3000 N / mm2 or more. (2) The breaking strain is 0.5% or more. (3) The shear adhesion strength is 0.5 N / mm2 or more.

3. The fiber sheet is adhered to the resin mortar layer by the resin mortar or a resin adhesive. The reinforcing structure for a concrete structure according to Claim 1 or 2.

4. The fiber sheet is disposed at a position where the distance from the surface of the reinforcing layer is shorter than the distance from the surface of the concrete structure. The reinforcing structure for concrete according to any one of Claims 1 to 3.

5. The fiber sheet is a fiber sheet in which a plurality of fiber reinforced plastic wire rods containing the reinforcing fibers are arranged in a corrugated shape in the longitudinal direction and the wire rods are fixed to each other with a wire fixing material. The reinforcing structure for concrete according to any one of Claims 1 to 4.

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