JPH03292111A - Unidirectional arrangement hybrid reinforced fiber sheet, production thereof and reinforcing method for structure - Google Patents

Abstract

PURPOSE:To enable reinforcement excellent in workability in a reinforcing field and to enhance rupture strength of a structure and to prevent a crack by unidirectionally arranging and providing a first reinforced fiber high in rigidity and a second reinforced fiber high in toughness via an adhesive layer on one-side face of a substrate sheet. CONSTITUTION:A unidirectional arrangement hybrid reinforced fiber sheet 1 is constitut ed of a substrate sheet 2, a first reinforced fiber 4 high in rigidity and a second rein forced fiber 6 high in toughness which are unidirectionally arranged and bonded on one-side face of the substrate sheet 2 via an adhesive layer 3. Reinforcement is performed by impregnating the reinforced fiber 4 and 6 with room temp. setting type matrix resin in a reinforcing field such as a bridge and an elevated road and leaving this reinforced fiber to stand while sticking it to the reinforcing part of a structure and curing the matrix resin. Further the first fiber 4 has rigidity of >=5 ton/mm<2> modulus of elasticity and the second reinforced fiber 6 has breaking extension of at least 1.2%. Moreover this reinforced fiber 6 preferably has toughness larger than the breaking extension of the first reinforced fiber 4 by at least 20%.

Description

[Detailed Description of the Invention] The present invention provides for reinforcing structures such as bridges and elevated roads using fiber-reinforced plastics with good workability at the reinforcement site. The present invention relates to a single-array hybrid reinforcing fiber sheet for use in reinforcing a structure, which can be used for reinforcing a structure, and a method for manufacturing the same, and a method for reinforcing the structure.

Bridge piers such as bridges and elevated roads are being reinforced with fiber-reinforced plastics.

Conventional methods for reinforcing it are: (1) pasting hardened fiber-reinforced plastic on the reinforced parts of the piers; (2) pasting prepreg on the reinforced parts of the piers to prevent deformation during heat curing. (3) Wrap a reinforcing fiber cloth around the reinforced part of the pier and impregnate it with a room-temperature curing matrix resin to create a fiber-reinforced plastic. A known method is to create a fiber-reinforced plastic by leaving it to harden after winding.

However,
Although the above method (1) has good reinforcement efficiency, it has a major drawback in that it cannot be reinforced at curved locations.

(Method 2) has the drawback that the prepreg attached to the reinforced portion of the pier must be heat-cured on site, and the heat-cure process is not easy.

In method (3), reinforcing fibers are used in a cross pattern such as plain weave or twill weave, so the strength of the reinforcing fibers is weak at the point where the warp and weft intersect. The disadvantage is that a strong reinforcing effect cannot be obtained.

In addition to the above, another method has been considered in which reinforcing fiber threads impregnated with resin are wound on-site at the reinforcement points of bridge piers using the filament winding method, and then hardened to form fiber-reinforced plastic, but this method is limited in terms of what can be reinforced. However, there are disadvantages such as high equipment costs.

Therefore, in view of the above-mentioned current situation, an object of the present invention is to make it possible to perform reinforcement with good ease of implementation at the reinforcement site and to improve reinforcement strength when reinforcing structures such as bridges and elevated roads using fiber-reinforced plastics. An object of the present invention is to provide a one-sided array hybrid reinforcing fiber sheet that can be used for reinforcing a structure, a method for producing the same, and a method for reinforcing a structure.

The above-mentioned object is achieved by the one-sided hybrid reinforcing fiber sheet, the method for manufacturing the same, and the method for reinforcing a structure according to the present invention.

In summary, the present invention comprises a support sheet, first reinforcing fibers having high rigidity and second reinforcing fibers having high toughness, which are arranged and bonded in one direction on one side of the sheet via an adhesive layer. This is a unidirectionally arranged hybrid reinforcing fiber sheet characterized by being made of reinforcing fibers. Preferably, the elastic modulus of the first reinforcing fiber is 5 tons/m m '' or more, the elongation at break of the second reinforcing fiber is 1.2% or more, and
The elongation at break is 20% or more greater than the elongation at break of the reinforcing fiber.

Furthermore, the present invention provides an adhesive layer on one surface of the support sheet, and a first reinforcing fiber having high rigidity and a second reinforcing fiber having high toughness are bonded together on one surface of the sheet. This is a method for producing a unidirectionally aligned hybrid reinforcing fiber sheet, characterized in that the sheet is bonded in a unidirectionally aligned manner. The first and second reinforcing fibers are formed by arranging fiber bundles of these reinforcing fibers in one direction with or without gaps on the adhesive layer on one surface of the sheet. By crushing the sheet from above and breaking it up, it can be adhered onto one surface of the sheet.

Furthermore, the present invention provides the method of impregnating the first and second reinforcing fibers with a room-temperature-curable matrix resin, and then attaching the unidirectionally arranged hybrid reinforcing fiber sheet to the surface of the reinforced portion of the structure. Alternatively, the reinforcing fiber sheet is applied after applying a room temperature curing matrix resin to the surface of the reinforced part of the structure, or the reinforcing fiber sheet is pasted to the surface of the reinforced part of the structure, and then the reinforcing fiber sheet is applied. A room temperature curing matrix resin is infiltrated into the first
This method of reinforcing a structure is characterized in that the second reinforcing fiber is impregnated with the matrix resin, and then the matrix resin is cured.

Oigoike Pond Examples of the present invention will be described below.

FIG. 1 is a sectional view showing an embodiment of the unidirectionally aligned hybrid reinforcing fiber sheet of the present invention.

The unidirectionally arranged hybrid reinforcing fiber sheet 1 of the present invention includes:
A support sheet 2, first reinforcing fibers 4 with high rigidity arranged and bonded in one direction via an adhesive layer 3 on one surface of the support sheet 2, and second reinforcing fibers with high toughness. The reinforcing fibers 4 and 6 are impregnated with a matrix resin so that they can be used for reinforcement at reinforcement sites such as bridges and elevated roads.

According to the present invention, a room-temperature curing resin is used as the matrix resin, and by leaving the reinforcing fiber sheet 1 attached to the surface of the reinforced portion of the structure, the matrix resin is cured and the fiber-reinforced sheet is made into a fiber-reinforced plastic. As a result, the structure is reinforced.

In the present invention, first reinforcing fibers 4 having high rigidity and second reinforcing fibers 6 having high toughness are disposed on one surface of the support sheet 2.
The fiber-reinforced sheet 1 is made into a hybrid by providing two types of reinforcing fibers.When reinforcing a structure by using this as a fiber-reinforced plastic, the structure is destroyed by the first reinforcing fibers 4, which have high rigidity. The strength is increased to prevent cracks from easily occurring, while the second reinforcing fibers 6 with high toughness increase the fracture toughness of the structure, preventing it from immediately breaking even if a crack occurs in the structure. This is to extend the time it takes to reach the destination.

Figure 2 shows the response of the fiber-reinforced plastic when a vertical load is applied to the surface of the hybridized fiber-reinforced plastic, which is obtained from a hybrid reinforced fiber sheet containing reinforcing fibers with high rigidity and reinforcing fibers with high toughness. 3 is a graph schematically showing an elongation strain curve. FIG. 3 is a graph similar to FIG. 2 in the case of a fiber-reinforced plastic obtained from a reinforced fiber sheet provided with one type of reinforcing fiber that has higher rigidity but lower toughness than the above.

In the case of hybrid fiber-reinforced plastics,
As shown in Figure 2, the stress σ is different from non-hybridized fiber reinforced plastics, but the elongation strain ε is large, and even if the reinforcing fibers with high rigidity break initially, the reinforcing fibers with high toughness elongate significantly. While preventing immediate rupture, the reinforcing fibers with high toughness reach the final rupture, so the area surrounded by the curve in the figure shows a large fracture energy. That is, it takes a long time for the entire fiber-reinforced plastic to break down.

On the other hand, in the case of non-hybridized fiber-reinforced plastic, as shown in Figure 3, the stress σ is high but the elongation strain ε is small, and once the reinforcing fibers begin to break, they do not stretch and immediately reach the final break. Therefore, the fracture energy indicated by the area surrounded by the curve in the figure is small. That is, the time required for the entire fiber-reinforced plastic to break down is short.

In this way, by hybridizing fiber-reinforced plastic using the hybrid reinforcing fiber sheet 1 that has two types of reinforcing fibers, the reinforcing fibers 4 with high rigidity and the reinforcing fibers 6 with high toughness, the fracture strength of the structure can be improved. It is possible to increase the fracture toughness of the structure to prevent it from easily forming cracks, and to prevent the structure from immediately breaking even if a crack occurs, thereby prolonging the time required for the structure to break.

Therefore, safety can be ensured when reinforcing a structure using fiber-reinforced plastic.

Practically, the first reinforcing fiber 4 has an elastic modulus of 5 tons/
It is preferable that the second reinforcing fibers 6 have a rigidity of 1.2% or more and a toughness that is 20% or more greater than the elongation at break of the first reinforcing fibers 4. It is preferable that the elastic modulus of the first reinforcing fiber 4 is 5.
If it is less than ton/mm2, the rigidity is too low and the fracture strength of the structure cannot be improved sufficiently. When the elongation at break of the second reinforcing fibers 6 is less than 1.2% and is not greater than the elongation at break of the first reinforcing fibers 4 by 20% or more, the fracture toughness of the construct will not be sufficiently improved.

The reinforcing fibers 4 and 6 may be various reinforcing fibers such as pitch-based carbon fiber, boron fiber, PAN-based carbon fiber, laminated fiber, glass fiber, steel fiber, polyester fiber, polyethylene fiber, etc., as long as the combination satisfies the above characteristic values. can be used.

As the support sheet 2, scrim cloth, glass cloth, release paper, nylon film, etc. are used. Normally, the support sheet 2 does not need to have resin permeability, but if you want to be able to impregnate the matrix resin into the reinforcing fibers 4 and 6 after attaching the reinforcing fiber sheet 1 to the reinforced parts of the structure, , the above-mentioned scrim cloth, glass cloth, etc. are used for the sheet 2. The thickness of the support sheet 2 may be about 1 to 500 μm, preferably about 5 to 1004 cm, from the viewpoint of having flexibility and strength capable of supporting the reinforcing fibers 4 and 6.

As an adhesive for forming the adhesive layer 3, in principle, a small amount of reinforcing fibers 4 and 6 may be used on the support sheet 2 (any adhesive may be used as long as the reinforcing fibers 4 and 6 are bonded temporarily, but reinforcing fibers 4 and 6 made of matrix resin may be used). It is preferable to give the same reinforcing effect to the adhesive layer 3. From this point of view, it is preferable to use a resin that has good compatibility with the matrix resin as the adhesive, for example, using an epoxy resin as the matrix resin. When used, it is preferable to use an epoxy adhesive.

The thickness of the adhesive layer 3 is 10 to 30 μm, since it is sufficient to temporarily bond the reinforcing fibers 4 and 6.
A certain degree is fine.

The reinforcing fibers 4 and 6 are made into filaments by arranging a large number of fiber bundles converged with a convergence agent or lightly twisted converged fiber bundles on the adhesive layer 3 and crushing them from above to loosen them slightly. As a result, the reinforcing fibers 4 and 6 are laminated in multiple layers by bonding using a binding agent or twisting, and are adhered to one surface of the support sheet 2 through the adhesive layer 3 while being arranged in one direction. .

In this case, the multiple layers of reinforcing fibers 4 and 6 are shown in FIG. 4(a).
As shown in the figure, these fiber bundles 4A and 6A are arranged closely in one direction on one side of the support sheet 2 with the adhesive layer 3 interposed between them, and the fiber bundles 4A and 6A are crushed from above to form the fibers. Glue the lower parts of bundles 4A and 6A to adhesive layer 3,
As shown in FIG. 4(b), they may be provided densely on the support sheet 2 without any spacing in the lateral direction, or as shown in FIG.
As shown in a), the fiber bundles 4A and 6A are arranged in one direction with an interval in the lateral direction on the support sheet 2 via the adhesive layer 3, and the fiber bundles 4A and 6A are similarly crushed from above. Alternatively, the lower portions of the fiber bundles 4A and 6A may be adhered to the adhesive layer 3, and the fiber bundles 4A and 6A may be sparsely provided on the support sheet 2 at intervals in the lateral direction, as shown in FIG. 5(b).

The fiber bundles 4A and 6A can be used with or without opening between the fibers 4, between the fibers 6, that is, between the filaments. The degree of crushing of the fiber bundles 4A and 6A depends on the desired layer thickness of the multiple layers of fibers 4 and 6 arranged by this, but in the case of carbon fibers, carbon fibers with a diameter of 5 to 15 μm are used. For example, when a carbon fiber bundle is made of about 12,000 filaments, it is crushed so that the width in the lateral direction becomes about 5 mm.

The unidirectionally aligned hybrid reinforcing fiber sheet 1 of the present invention as described above can be manufactured, for example, as shown in FIG. 6.

That is, after applying adhesive on one side of the support sheet 2 supplied from the sheet supply roll 7 with an adhesive coating roll 8 to form an adhesive layer 3, the sheet 2 is fed into the pressure section 9. At the same time, a fiber bundle 4A of the first reinforcing fibers 4 having high rigidity is fed into the pressurizing part 9 from the reinforcing fiber supply roll 10a, and a fiber bundle 6A of the second reinforcing fiber 6 having high toughness is fed from the reinforcing fiber supply roll 10b. , the fiber bundles 4A and 6A are arranged in one direction on the adhesive layer 3 on the sheet 2. Furthermore, the release paper 12 is fed from the release paper roll 11 to the pressure unit 9, and the fiber bundle 4A is
And release paper 12 is placed on top of 6A.

In this state, the pressure rollers 13a and 13b of the pressure unit 9
Pressure is applied to crush the fiber bundles 4A and 6A, and at the same time, the reinforcing fibers 4.6, which have been slightly separated by this, are adhered to one surface of the sheet 2 via the adhesive layer 3. Thereafter, by winding up the release paper 12 with a release paper take-up roll 14, the first reinforcing fibers 4 with high rigidity and the second reinforcing fibers with high toughness are placed on one side of the support sheet 2 via the adhesive layer 3. A unidirectionally arranged hybrid reinforcing fiber sheet 1 is obtained by arranging and bonding the reinforcing fibers 6 of No. 2 in one direction.

The reinforcing fiber sheet 1 is wound up onto a sheet winding roll 17 after the reinforcing fibers 4 and 6 are covered with a cover film 16 supplied from a film supply roll 15 as needed.

In the present invention, as described above, the reinforcing fiber sheet 1 is used for reinforcement at reinforcement sites such as bridges and elevated roads by impregnating the reinforcing fibers 4.6 with a room-temperature curing matrix resin. For the matrix resin of the mold, an epoxy resin or the like is used, which is made by adjusting the blend of curing agents so that it hardens at room temperature. According to this, fiber-reinforced sheet 1 is placed in the reinforced area.
The matrix resin can be cured and made into a fiber-reinforced plastic by leaving it as it is pasted.However, the present invention does not preclude the promotion of curing of the matrix resin by heat curing. .

According to the invention, the reinforcement of the construction is carried out as follows.

That is, in one embodiment of the present invention, the reinforcing fibers 4. on the unidirectionally arranged hybrid reinforcing fiber sheet 1 are applied at the site of reinforcing structures such as bridges and piers of elevated roads using appropriate application means such as rollers, brushes, and sprayers. 6 is coated with a room-temperature curing matrix resin and impregnated, and as shown in FIG.
The fiber-reinforced sheet 1 is pasted around the reinforced portion 18 with the sides 6 and 6 as the reinforced portion 18 side of the structure, and a desired number of sheets are laminated. Next, after impregnating the matrix resin with a hand roller, etc., wrap a pressure tape over it to cover it, and then leave it as it is to harden the matrix resin, converting the sheet 1 into a fiber-reinforced plastic. Just do it. As a result, the structure is reinforced with the hybridized fiber-reinforced plastic.

In another embodiment of the present invention, as shown in FIG. 8, a room-temperature curing matrix resin 19 is applied to a thickness of, for example, about 100 μm around the reinforced portion 18, and then the side of the reinforcing fibers 4 or 6 is reinforced. A desired number of unidirectionally arranged reinforcing fiber sheets 1 are stacked on the side of the portion 18, and the sheets 1 are attached by pressing, and at the same time, the reinforcing fibers 4 and 6 are impregnated with the matrix resin 19. In this case, if the support sheet 2 is not permeable to resin, each time the next sheet 1 is laminated on the previously laminated sheet 1, the previous sheet 1 is
A matrix resin may be further applied to the surface. Thereafter, in the same manner as described above, the laminated sheet 1 may be covered with a pressure tape, etc., and then left as is to harden the matrix resin, thereby making the sheet 1 a fiber-reinforced plastic. As a result, the structure is reinforced by the hybridized fiber-reinforced plastic.

In yet another embodiment of the present invention, the unidirectionally aligned hybrid reinforcing fiber sheet 1 uses a support sheet 2 that is permeable to a resin. As shown in FIG. 9, first, a resin similar to the matrix resin is applied as a brimer 20 on the peripheral surface of the reinforced portion 18, and the desired number of sheets 1 are laminated on top of the brimer 20, and then the outermost layer is A room temperature curable matrix resin 19 is applied onto the sheet 1 using a roller or the like and permeated through the sheet 2, so that the reinforcing fibers 4 and 6 are impregnated with the matrix resin 19. After that,
Similarly to the above, the laminated sheet 1 may be covered by wrapping a pressure tape or the like, and then left as is to harden the matrix resin 19, thereby making the sheet 1 a fiber-reinforced plastic. As a result, the structure is reinforced by the hybridized fiber-reinforced plastic.

The present invention is configured as described above. According to this, when reinforcing structures such as bridges and elevated roads with fiber-reinforced plastic, first and second reinforcing fibers are arranged in one direction on one surface of a support sheet. The unidirectionally arranged hybrid reinforcing fiber sheet 1 is used, and the reinforcing fibers 4 and 6 are impregnated with a room-temperature curing matrix resin at the reinforcement site, so the sheet 1 impregnated with matrix resin is used at the reinforcement site. By pasting it on the surrounding area and leaving it as it is, the matrix resin can be cured and the sheet 1 can be made into a fiber reinforced plastic. It can be well reinforced with fiber-reinforced plastic.

However, in the hybrid reinforcing fiber sheet, the first reinforcing fibers 4 are reinforcing fibers with high rigidity and an elastic modulus of 5 tons/mm'' or more, and the second reinforcing fibers 6 are reinforcing fibers with a breaking elongation of 1.2.
% or more and 20% more than the elongation at break of the first reinforcing fiber 4
Since fiber-reinforced plastic is hybridized as reinforcing fibers with high toughness, the first reinforcing fibers 4 with high rigidity can increase the fracture strength of the structure and prevent cracks from occurring easily. On the other hand, the fracture toughness of the structure is increased by the second reinforcing fibers 6 having high toughness, and even if a crack occurs in the structure, it can be prevented from immediately breaking and the time required for the structure to break can be extended. In addition, reinforcing fiber 4
．． 6 are arranged in one direction, so there is no decrease in the strength of the fiber-reinforced plastic unlike when they are arranged in a cross pattern.

Furthermore, since the matrix resin is cured after the reinforcing fiber sheet 1 is pasted around the reinforced area, reinforcement can be carried out even in curved reinforced areas.

As explained above, in the present invention, the first reinforcing fibers with high rigidity and the second reinforcing fibers with high toughness are arranged in one direction on one side of the support sheet. A unidirectionally aligned hybrid reinforcing fiber sheet is used, and the reinforcing fibers are impregnated with a room-temperature curing matrix resin at the reinforcement site. By pasting it on the surrounding area and leaving it as is, the matrix resin will harden and become fiber reinforced plastic, allowing for easy reinforcement without having to do the troublesome work of heating and hardening the matrix resin at the reinforcement site. be able to. Moreover, it is possible to increase the fracture strength of the structure so that cracks do not easily occur, and it is also possible to increase the fracture toughness of the structure to prevent it from immediately breaking even if a crack occurs in the structure.

Furthermore, since the reinforcing fibers are arranged in one direction, the reinforcing strength of the resulting fiber-reinforced plastic can be improved. Further, even if the reinforced portion is curved, reinforcement can be performed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the unidirectionally aligned hybrid reinforcing fiber sheet of the present invention. Figure 2 shows the response of the fiber-reinforced plastic when a vertical load is applied to the surface of the hybridized fiber-reinforced plastic, which is obtained from a hybrid reinforced fiber sheet containing reinforcing fibers with high rigidity and reinforcing fibers with high toughness. 3 is a graph schematically showing an elongation strain curve. FIG. 3 is a graph similar to FIG. 2 in the case of a fiber-reinforced plastic obtained from a reinforced fiber sheet provided with one type of reinforcing fiber that has higher rigidity but lower toughness than the above. FIG. 4(a) is a sectional view showing one aspect of how the reinforcing fiber bundles are arranged in the reinforcing fiber sheet of FIG. 1(a). FIG. 4(b) is a cross-sectional view showing the arrangement of reinforcing fibers obtained from the fiber bundle of FIG. 4(a). FIG. 5(a) is a sectional view showing another aspect of how the reinforcing fiber bundles are arranged in the reinforcing fiber sheet of FIG. 1(a). FIG. 5(b) is a cross-sectional view showing the arrangement of reinforcing fibers obtained from the fiber bundle of FIG. 5(a). FIG. 6 is an explanatory diagram showing an embodiment of the manufacturing method of the present invention. FIG. 7 is a sectional view showing an embodiment of the reinforcing method of the present invention. FIG. 8 is a sectional view showing another embodiment of the reinforcing method of the present invention. FIG. 9 is a sectional view showing still another embodiment of the reinforcing method of the present invention. 1: Reinforced fiber sheet 2: Support sheet 3: Adhesive layer 4.6: Reinforced fibers 4A, 6A: Fiber bundle 18: Reinforcement location 19: Matrix resin 20 Nib primer Figure 1 Figure 4 (0) Figure 5 ( a) Fig. 2 Fig. 3 Fig. 6 Elongation strain ε Elongation strain ε Fig. 7 Fig. 8

Claims (1)

[Scope of Claims] 1) A support sheet, and a highly rigid first layer arranged in one direction and adhered to one surface of the sheet via an adhesive layer.
A unidirectional hybrid reinforced fiber sheet comprising reinforcing fibers and second reinforcing fibers having high toughness. 2) The elastic modulus of the first reinforcing fiber is 5 tons/mm^3 or more, and the elongation at break of the second reinforcing fiber is 1.2% or more and greater than the elongation at break of the first reinforcing fiber. The unidirectionally aligned hybrid reinforcing fiber sheet according to claim 1, which is 20% or more larger. 3) An adhesive layer is provided on one surface of the support sheet, and first reinforcing fibers with high rigidity and second reinforcing fibers with high toughness are arranged in one direction on one surface of the sheet. 1. A method for producing a unidirectionally aligned hybrid reinforced fiber sheet, characterized in that the sheet is bonded with a unidirectionally aligned hybrid reinforced fiber sheet. 4) The first and second reinforcing fibers are made by arranging fiber bundles of these reinforcing fibers in one direction on the adhesive layer on one side of the sheet with or without gaps. 4. The method for manufacturing a unidirectionally aligned hybrid reinforcing fiber sheet according to claim 3, wherein the fiber bundles are adhered onto one surface of the sheet by crushing and separating the fiber bundles from above. 5) An adhesive layer is provided on one surface of the support sheet, and first reinforcing fibers with high rigidity and second reinforcing fibers with high toughness are arranged in one direction on one surface of the sheet. After impregnating the first and second reinforcing fibers with a room-temperature curable matrix resin, a unidirectionally aligned hybrid reinforcing fiber sheet formed by bonding is attached to the surface of the reinforced part of the structure, and then the A method for reinforcing a structure, characterized by curing a matrix resin. 6) An adhesive layer is provided on one surface of the support sheet, and first reinforcing fibers with high rigidity and second reinforcing fibers with high toughness are arranged in one direction on one surface of the sheet. A unidirectionally arranged hybrid reinforcing fiber sheet formed by adhering is applied to the surface of the reinforced part of the structure with a room temperature curing matrix resin, and then attached, and the first and second reinforcing fibers are impregnated with the matrix resin. A method for reinforcing a structure, comprising: curing the matrix resin, and then curing the matrix resin. 7) An adhesive layer is provided on one side of a resin-permeable support sheet, and a first reinforcing fiber with high rigidity and a second reinforcing fiber with high toughness are unidirectionally applied on one side of the sheet. A unidirectionally arranged hybrid reinforcing fiber sheet formed by arranging and adhering is pasted on the surface of the reinforced portion of the structure, and then a room temperature curing matrix resin is infiltrated into the reinforcing fiber sheet to form the first and second reinforcing fiber sheets. 1. A method for reinforcing a structure, comprising impregnating reinforcing fibers with the matrix resin, and then curing the matrix resin.