JP2003013612A - Method for reinforcing concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reinforcing a concrete structure, especially fit for a portion of the concrete structure, making contact with water. SOLUTION: The method for reinforcing the concrete structure is comprised of a step of preliminarily treating a surface of the concrete structure, a step of applying a resin composition which is hardened under the presence of water, to the surface of the preliminarily treated concrete structure, a step of sticking a reinforcing fiber material to the surface of the concrete structure which has the resin composition applied thereto, and a step of hardening the resin composition to merge the concrete structure with the reinforcing fiber material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for reinforcing a concrete structure and a reinforced concrete structure.

[0002]

2. Description of the Related Art Concrete structures such as breakwaters, seawalls, quays, seawalls, levees, jetties, towers and dams used in the natural environment such as the ocean, lakes and rivers are subject to temperature fluctuations during the day or season. Due to the accumulation of thermal strain, the action of carbon dioxide gas, acid rain, etc., the concrete deteriorates over time, causing cracks, and the strength of the concrete remarkably decreases.

There is also a problem that the strength of a concrete structure is deteriorated by the corrosion of reinforcing bars due to the permeation of salt or seawater in sea sand used as an aggregate of concrete. In order to solve such a problem, for example, a technique of applying an anticorrosive paint to the surface of concrete for repair has been developed, but the problem of strength reduction has not been fundamentally solved.

On the other hand, Japanese Patent Application Laid-Open No. 11-21847 describes a method of reinforcing a concrete structure for skeleton by pouring and molding a reinforcing concrete layer using a mold. However, even with this method, there is an unavoidable problem of deterioration of the surface concrete layer itself, and there is a problem that the concrete layer provided on the surface easily peels off from the concrete structure of the skeleton, so there is a limit to improving durability and maintaining strength. there were.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is a breakwater, a seawall, a quay wall, a seawall, an embankment, a jetty, a tower, a dam, etc. used in a natural environment such as an ocean, a lake or a river. The present invention is to provide a reinforcing method and a reinforcing structure suitable for reinforcing a concrete structure, especially a part in contact with water.

[0006]

According to the present invention, a step of pretreating a surface of a concrete structure and a resin composition which is cured in the presence of water are applied to the surface of the pretreated concrete structure. A concrete structure including a step, a step of attaching a reinforcing fiber material to the surface of a concrete structure coated with a resin composition, and a step of curing the resin composition to integrate the concrete structure and the reinforcing fiber material. To provide a reinforcing method.

A resin composition containing a polysulfide-modified resin is preferably used as the resin composition which is reactively cured in the presence of water.

The resin composition has 3 carbon atoms.
It is preferable to use a curing agent containing a curing agent in the range of 15 to 15, and it is preferable to use the curing agent by encapsulating it in a microcapsule or by supporting it on an inorganic substance having fine pores.

Furthermore, it is preferable to use a resin composition containing a surfactant.

Further, it is preferable to use a woven fabric, a mesh, a knitted fabric or a non-woven fabric of reinforcing fibers as the reinforcing fiber material, or to use an FRP plate as the reinforcing fiber material.

The reinforcing fiber material has a tensile strength of 50.
It is more preferable to use a material in the range of 0 to 5,000 MPa.

The invention further features a concrete structure reinforced by the method described above.

Furthermore, the present invention provides a concrete breakwater, a seawall, a quay, which is reinforced by the above-mentioned method.
It features revetments, levees, jetties, towers or dams.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A method for reinforcing a concrete structure according to the present invention comprises a step of pretreating the surface of the concrete structure and a resin which cures on the surface of the pretreated concrete structure in the presence of water. A step of applying the composition, a step of attaching a reinforcing fiber material to the surface of the concrete structure coated with the resin composition, and a step of curing the resin composition to integrate the concrete structure and the reinforcing fiber material including. Reinforcement of the underwater portion may be carried out in the same manner as construction in the atmosphere.

The pretreatment is to grind the surface of the concrete structure to be reinforced with a sander or the like so as to level the unevenness so that the resin composition can be easily adhered, and to remove stains. Refers to the process It is advisable to remove the corners from the inside and outside corners. It is better to fill the recesses with putty.

Next, the resin composition is applied to the surface which has been pretreated. As the resin composition, one that reacts and cures even in the presence of water is used. Apply with a roller,
A comb iron, spatula, brush or the like may be used. The application amount is not particularly limited, and the application amount is such that the reinforcing surface of concrete is completely covered with the resin composition. In order to ensure the uniformity of the coating layer, it may be applied once, but may also be applied several times. At the time of coating, the resin composition may be diluted with a solvent as needed. Also,
It is also preferable to apply a primer treatment in order to enhance the adhesiveness. As the primer, a substance that retains curability in water may be selected, and the resin composition used in the present invention can also be used as the primer.

Next, the reinforcing fiber material is attached to the coated surface of the resin composition, and the reinforcing fiber material and the concrete structure are integrated by using the resin composition. The reinforcing fiber material is used for transmitting bending stress and shear stress acting on the concrete structure to the reinforcing fiber material to disperse the stress.
By integrating the reinforcing fiber material and the concrete structure, the reinforcing effect of the concrete structure by the reinforcing fiber material can be exhibited.

Next, the resin composition in which the reinforcing fiber material and the concrete structure are integrated is cured. As a curing method, curing may be carried out in a natural state, or if necessary, heating may be performed to shorten the curing time. Alternatively, it is possible to irradiate ultraviolet rays to accelerate the curing. It may be cured using various other means.

Further, after curing, a step such as surface finishing can be added if necessary. The design may be finished according to the purpose by various methods such as mortar coating, resin finishing, and spray coating. Further, the finish coated surface may be flat or may be provided with various uneven patterns such as an embossed pattern.

The resin composition must have wettability and adhesiveness to both the reinforcing fiber material and the concrete structure.
In the present invention, the resin composition used to bond and integrate the reinforcing fiber material and the concrete structure is a resin composition which is fluid at the time of construction but hardens with time. As the curing type, various materials such as room temperature curing, heating curing, and ultraviolet curing can be used. In order to cure, it is preferable that the resin composition contains a curing agent. An ordinary two-component mixed curing type of a main agent and a curing agent may be used, or a one-component type resin composition containing a latent curing agent such as a Mannich type curing agent or a ketimine type curing agent may be used. .

As the resin composition, unsaturated polyester resin, vinyl ester resin, epoxy resin, silicone modified resin, polysulfide modified resin, polyurethane resin, phenol resin, formal resin, urea resin and the like are used in view of compatibility with concrete. Therefore, it can be used by dissolving it in a solvent or can be used without a solvent. A moisture-curable acrylic resin composition, various adhesives and sealing agents for use around water can also be used. Above all,
In particular, the polysulfide-modified resin can be preferably used because it has good affinity with concrete and good curability in the presence of water.

The polysulfide-modified resin is one having one or more units containing S in the main chain or side chain. Of course, the polymer is a collection of various molecular weights, and the S content in the monomer unit may be different. Therefore, the average amount of S is about 0 to 3 units. More _{particularly, -X- (R 1 -S a)} b -R 2
A group called -Y- (polysulfide chain) is contained in the main chain or side chain. Here, R ₁ and R ₂ are
Divalent methylene group (-CH ₂ -), the divalent ether group (-CH ₂ OCH ₂ -), divalent isopropanol group _{(-CH 2 CH (OH) CH} 2 -), 2 -valent ethanol group ( _{-CH 2 CH (OH) -)} , also, (- CH _{2
CH 2 OCH 2 OCH 2 CH 2} -), (- CH 2 CH 2
O-) and the like, which may be one or more and may be a combination thereof. R ₁ and R ₂ may be the same or different. X and Y are -S-, -O-, -NH
It is a group selected from-. a is 0 for each repeating unit
Is an integer of 5 and b is an integer of 1 to 50. However,
X or Y when a is 0 for all repeating units
At least one of them is a -S- group. a is 1 to 2.5
Is preferred. It suffices that the above polysulfide chain is contained somewhere in the structure of the resin.

The synthesis method is, for example, in the case of a polysulfide-modified epoxy resin, a sulfur-containing monomer or oligomer (including a prepolymer) having a reactive functional group.
And an epoxy prepolymer having two or more epoxy groups in the molecule, or an addition reaction between a polysulfide polythiol and an epoxy prepolymer. In the case of a polysulfide-modified urethane resin, a one-pack type urethane contains a polysulfide chain in the main chain of a part or all of the molecule, and a two-pack type urethane also has a polysulfide chain in the prepolymer and / or the curing agent. Should be included. In the case of the two-pack type, the polysulfide resin (terminal SH) itself may be used as the curing agent.

The resin composition may be used alone or as a blend of resin compositions having different compositions. Alternatively, these resin compositions may be a polymer (homopolymer) composed of a single repeating unit, or a copolymer composed of two or more kinds of repeating units.

The resin composition has 3 carbon atoms.
It is preferable to use one containing a curing agent in the range of -15. When the number of carbon atoms is less than 3, the curing agent is easily deactivated by water, which makes it difficult to cure in water. On the other hand, when the number of carbon atoms exceeds 15, the curing reaction is delayed and it is difficult to carry out the actual work. For the purpose of underwater curing, the number of carbon atoms in the curing agent is 3
It is preferable that the curing agent is in the range of 15 to 15, but as the curing agent, any of saturated or unsaturated aliphatic compounds and aromatic compounds can be preferably used. In addition, it may be linear or may have a branched structure. The number of carbon atoms in the curing agent is 3 to
Within the range of 15, even if water is present in the course of the curing reaction, the adhesion does not easily become unstable.

The curing agent is preferably used by being encapsulated in microcapsules in order to maintain the curability in water. As the curing agent, a compound that cures the resin composition may be selected according to the type of the resin composition. Various types of microcapsules can be used, but those made of a polymeric substance or an oligomer can be preferably used. A material may be selected that causes the walls of the microcapsules to collapse when pressure is applied. The material is not particularly limited as long as it has this property. In the process of impregnating the resin composition while attaching the reinforcing fiber material to the surface of the concrete structure and crimping the microcapsules, the curing agent in the microcapsules is released into the resin composition to react. Good.

Alternatively, as the material for forming the microcapsules, a substance that gradually decomposes or dissolves when contacted with water can be selected. The decomposition rate or dissolution rate of the microcapsules is appropriately selected according to the construction conditions. For that purpose, it is possible to control the degree of polymerization of the polymer substance or oligomer which forms the microcapsules, or to control the number of functional groups relating to degradability or water solubility.

The size of these microcapsules is not particularly limited. A known means may be used to enclose the curing agent in the microcapsules.

Further, as one of the preferable modes for maintaining the underwater curability, there is a method of supporting a curing agent for a resin composition on an inorganic substance having fine pores. As the curing agent, a substance having a property of curing the resin composition may be selected according to the type of the resin composition. In order to support the curing agent on the inorganic substance having fine pores, for example, there is a method of bringing the curing agent and the inorganic substance having fine pores into contact with each other in a liquid-solid state.
When an inorganic substance carrying such a curing agent comes into contact with water on the concrete surface, molecular exchange occurs, water is taken into the fine pores, and instead the curing agent is supplied, so that the curing reaction proceeds rapidly on the concrete surface. . Examples of the inorganic substance exhibiting such an action include those having fine pores such as diatomaceous earth, zeolites and molecular sieves. The size of the fine pores is preferably about 0.05 to 10 nm as the diameter on the inlet side in order to adsorb water molecules and desorb molecules of the curing agent. The chemical composition or mineral composition is not particularly limited as long as it has such fine pores.

Furthermore, it is also preferable to use a resin composition containing a surfactant. When a hydrophobic resin composition is used, the surface of the concrete structure that is wet with water is hydrophilic, and it is preferable to use a surfactant in order to impart fixing stability of the resin cured product at the interface. The types of such surfactants include, for example, anionic type, cationic type, and amphoteric type. The type of surfactant, HLB characteristics, the amount added, etc. may be selected according to the chemical composition of the resin composition and the amount used.

An inorganic extender such as shirasu, glass balloon, silica fume, perlite and various fillers may be mixed with the above resin composition and used. The filler may have various forms such as fibrous form, spherical form, and irregular form, but is not particularly limited. The addition amount of these can be arbitrarily selected within a range that does not impair the adhesiveness and the workability. Flow characteristics of the resin composition, that is, in the sense of controlling the ease of application and thixotropy of the resin composition during construction,
It is also possible to add fine particles of carbon black or colloidal silica. Substances such as asphalt pitch and coal tar for enhancing salt water resistance may be mixed, if necessary, such as in contact with seawater.

It is also possible to add substances such as various dehydrating agents having a property of taking in water to the resin composition, superabsorbent resins, gypsum and cement, if necessary. When these are added, the construction can be easily carried out in the case of rainfall, and the surface of the concrete structure in water or near the water surface which is in a dipped or wet state can be easily reinforced.

The viscosity of the resin composition used in the present invention is preferably about 1 to 50 Pa.sec at 20.degree. C. in consideration of the coating property on the concrete structure and the permeability to the reinforcing fiber material. If it is less than 1 Pa · sec, the resin will hang down during the construction, making the construction difficult, and if it exceeds 50 Pa · sec, the resin permeability into the reinforcing fiber material will be reduced. The curing time of the resin composition is preferably about 30 to 100 minutes at 20 ° C. If necessary, various curing accelerators and curing retarders can be added. Auxiliary agents such as penetrants and surfactants for enhancing the affinity with concrete and reinforcing fiber materials can be added to the resin composition.

Examples of the reinforcing fiber material include sheet materials such as woven fabrics, meshes, knits and non-woven fabrics of reinforcing fibers, and FRP.
Use a plate. In the case of the FRP plate, it is preferable that the FRP plate has a flexibility to conform to the shape of the concrete structure. The reinforcing fiber material may be appropriately cut beforehand according to the size of the portion to be reinforced. When the reinforcing fiber material is in the form of a sheet, it is also preferable that it is attached to the coating layer while unwinding the material wound around a paper tube or the like on site and the workability is good.

The sheet-like material may be a plain weave, a twill weave, a velvet weave, a pile weave, a double weave, or the like as a woven fabric, a mesh-like structure composed of fiber bundles or twisted yarns as a mesh, and a circular knit as a knitted fabric. Knitted fabrics, tubular knitted fabrics, Russell knitted fabrics, tricot knitted fabrics and the like are preferably used as the nonwoven fabrics such as spunbonded nonwoven fabrics, needle punched nonwoven fabrics, melt blown nonwoven fabrics, flash spun nonwoven fabrics and spunlaced nonwoven fabrics. A woven fabric or knitted fabric can be preferably used in terms of strength development.

The fibers forming such a sheet may be long fibers or short fibers, and may be twisted if necessary. The fibers may be preferentially oriented in one direction, or may be orthogonal or crossed in two directions. Alternatively, the fibers may have a structure having no orientation of fiber orientation, but for the purpose of the present invention, it is preferable to preferentially orientate in one direction or two directions.

The thickness of the monofilament constituting the sheet material of the reinforcing fiber material of the present invention is preferably about 0.01 to 5 dtex. The cross-sectional shape of the fiber may be a circular cross section, an elliptical cross section, or another irregular cross section.

As the material of the fibers, aromatic or aliphatic polyester fibers, aromatic or aliphatic polyamide fibers, polyvinyl alcohol fibers, acrylic fibers, carbon fibers, glass fibers and the like can be preferably used. The sheet-like material may be formed from one kind of these fibers, or may be formed from plural kinds of fibers.

The basis weight of the sheet-like material is preferably about 50 to 1000 g / m ² in consideration of handling property and resin impregnation property. Further, the thickness is appropriately about 0.05 to 2 mm. From the viewpoint of enhancing the impregnation property of the resin, it is preferable that the sheet-like material has appropriate voids, and the ventilation amount is 100 to 800 cm3 / cm2 / se under the condition of 25 ° C and 0.1013 MPa.
The range of c is preferable. If the air flow rate is below this range, the permeability of the resin will decrease, and conversely, if it exceeds this range,
The strength of the sheet-like material is lowered and the shape retention is deteriorated.

Examples of the reinforcing fiber used for the FRP plate in which the reinforcing fiber and the matrix resin are integrally combined are aromatic polyester fiber, aramid fiber, carbon fiber, glass fiber, barium titanate fiber, wollastonite fiber, polyvinyl. High strength fibers such as alcohol fibers and acrylic fibers can be preferably used. One of these may be selected, or two or more types of fibers may be mixed or mixed and used. The reinforcing fibers may be long fibers or short fibers.

As the matrix resin used for the FRP plate, unsaturated polyester resin, vinyl ester resin,
Polyurethane resin, polycarbonate resin, urea resin,
Epoxy resin, phenol resin, polyamide resin, polyimide resin, polyetherketone resin, polysulfone resin and the like can be preferably used. One of these may be used, a plurality of these may be blended, or a copolymerized polymer may be used.

The orientation of the fibers in the FRP plate is not particularly limited, but it is preferable that the fibers are preferentially oriented in one direction or two directions. A plate having a thickness of about 0.1 to 5 mm can be preferably used. If necessary, two or more plates can be laminated and used. In order to improve the adhesiveness between the FRP plate and the concrete structure, it is possible to previously attach fine particles to the surface of the FRP plate, attach a raised fabric, or roughen the surface to form irregularities. Is.

In order to exert the reinforcing effect of these reinforcing fiber materials, the tensile strength in the main direction in which the fibers are preferentially oriented is preferably 500 to 5000 MPa.

These reinforcing fiber materials are arranged on the surface of the concrete structure and bonded and integrated with the resin composition to reinforce. The entire surface of the concrete structure may be reinforced, and it is also preferable to selectively reinforced it at a necessary place for the purpose of bending or shearing. It may be appropriately selected depending on the shape of the structure, the age, and the place where the structure is installed. The sheet-like material and the FRP plate are used properly according to the site to be used.

When the reinforcing fiber material attached to the coating layer of the resin composition is pressed from above to bring the reinforcing fiber material and the concrete structure into close contact with each other, the reinforcing fiber material may be a woven fabric, a mesh, a knitted fabric, a non-woven fabric or the like. In the case of a sheet-like material, the resin composition is impregnated into the spaces between the fibers. When the reinforcing fiber material is a sheet-like material, it is used as a concrete structure by impregnating the resin composition into the fiber gap while removing bubbles by using a jig for construction such as a roller, a trowel, and a brush when pressing. A woven fabric, a mesh, a knitted fabric, and a reinforcing fiber material, which is a non-woven fabric, are compositely integrated through a resin composition. In the step of integrating, only one layer of the sheet may be used for reinforcement, or a plurality of layers may be laminated for reinforcement. In this case, different types of sheet materials such as woven fabric and non-woven fabric may be combined and laminated. When the reinforcing fiber material is an FRP plate, a tool such as a vibrator may be used in addition to the roller or the like for the purpose of closely adhering and integrating the material when it is attached to the concrete structure.

Further, the reinforced concrete structure of the present invention, or the concrete breakwater, seawall, quay wall, revetment, embankment, jetty, tower body, dam of the present invention is reinforced by the above-mentioned reinforcement method. . The reinforcing part may be a part in the atmosphere, a part in water, or a boundary region between these parts. These concrete structures can be suitably reinforced even if they are constructed in any of the ocean area, lake area, and river area. Examples of the tower body include a sign tower, an observation tower, a ship lighthouse, an aviation lighthouse, and a control tower.

[0047]

EXAMPLES The present invention will be described in more detail below with reference to examples.

[0048]

Example 1 The surface of a concrete structure of a breakwater whose surface is in a wet state was smoothed using a sander.

Next, a resin composition (weight ratio of bisphenol F type epoxy resin: 1,6-hexanediol diglycidyl ether of 70:30) containing metaphenylenediamine (6 carbon atoms) as a curing agent was prepared. .

This resin composition was applied to the surface of a concrete structure using a roller brush. Before the applied resin composition is cured, as a reinforcing fiber material, a plain woven fabric made of carbon fibers arranged in the vertical direction and the horizontal direction is attached thereon, and then the woven fabric is pressed using a grooved roller. After the resin composition was impregnated into the fiber gaps constituting the above, the resin composition was cured by natural curing for one day to be integrated with the concrete structure. The resin composition had good curing properties even when the concrete structure was wet.

The reinforced breakwater was excellent in practical strength such as bending and compression, and cracking was suppressed over the years.

[0052]

Example 2 The surface of the concrete structure of the quay of a harbor whose surface is in a wet state was smoothed using a sander.

Next, as a curing agent, 3,3'-dimethyl-
A resin composition containing 1% by weight of sorbitan oleic acid monoester as a nonionic surfactant in methylenebiscyclohexylamine (bisphenol F type epoxy resin: 1,6-hexanediol diglycidyl ether A weight ratio of 70:30 was prepared.

This resin composition was applied to the surface of a concrete structure using a roller brush. Before the applied resin composition is cured, as a reinforcing fiber material, a plain fabric in which carbon fibers are arranged in the warp direction and glass fibers in the transverse direction is attached thereon, and then pressed using a grooved roller. While impregnating the resin composition in the interstices of the fibers constituting the woven fabric, 1
The resin composition was cured by natural curing for 24 hours and integrated with the concrete structure. The resin composition had good curing properties even when the concrete structure was wet.

This reinforced quay was excellent in practical strength such as bending and compression, and cracking was suppressed over time.

[0056]

[Example 3] The surface of a concrete structure of a jetty with a wet surface was smoothed using a sander.

Next, metaxylenediamine as a curing agent was encapsulated in a microcapsule made of a formalin condensation resin by a known method. The particle size distribution of the microcapsules was 10 to 50 μm.

The microcapsules were mixed with a resin composition (a weight ratio of bisphenol F type epoxy resin: 1,6-hexanediol diglycidyl ether of 70:30) in a chemical equivalent amount required for curing, and a coating resin. A composition was prepared.

This resin composition was applied to the surface of a concrete structure using a roller brush. Before the applied resin composition is cured, a twill fabric in which polyparaphenylene terephthalamide fibers are arranged in the warp direction and the weft direction is attached as a reinforcing fiber material, and then it is pressed using a grooved roller. Meanwhile, the resin composition was impregnated in the interstices of the fibers constituting the woven fabric, and then naturally cured for one day to cure the resin composition and integrate it with the concrete structure. The resin composition had good curing properties even when the concrete structure was wet.

This reinforced jetty was excellent in practical strength such as bending and compression, and cracking was suppressed over time.

[0061]

[Example 4] The surface of a concrete structure of a jetty with a wet surface was smoothed using a sander.

Next, isophoronediamine was used as a curing agent and a mixture of zeolite A and zeolite X (weight ratio 5
0:50) by a known method. A coating material carrying the curing agent is mixed with a resin composition (a weight ratio of bisphenol F type epoxy resin: 1,6-hexanediol diglycidyl ether is 70:30) in an amount equivalent to the amount required for curing, and the mixture is applied. A resin composition for use was prepared.

This resin composition was applied to the surface of a concrete structure using a roller brush. Before the applied resin composition is cured, as a reinforcing fiber material, a twill fabric in which polyparaphenylene terephthalamide fibers are arranged in the warp direction and the weft direction is attached thereon, and then pressed using a grooved roller. Meanwhile, the resin composition was impregnated in the interstices of the fibers constituting the woven fabric, and then naturally cured for one day to cure the resin composition and integrate it with the concrete structure. The resin composition had good curing properties even when the concrete structure was wet.

The reinforced jetty was excellent in practical strength such as bending and compression, and cracking was suppressed over the years.

[0065]

[Example 5] FR using carbon fiber as reinforcing fiber and epoxy resin as matrix resin as reinforcing fiber material
A P-board was used to reinforce the concrete lighthouse with a polysulfide-modified epoxy resin. After smoothing the surface of the concrete structure of the lighthouse using a sander, the resin composition was applied and an FRP plate was attached before curing. The FRP plate and the concrete structure were brought into close contact with each other by pressing from above the attached FRP plate using a vibrator. 1 day and night cure naturally to cure the resin composition, FR
The P board and the concrete structure are integrated. The resin composition had good curing properties even when the concrete structure was wet.

The reinforced lighthouse was excellent in practical strength such as bending and compression, and cracking was suppressed over time.

[0067]

EFFECTS OF THE INVENTION A step of pretreating the surface of a concrete structure, a step of applying a resin composition which cures in the presence of water to the surface of the concrete structure which has been pretreated, and a step of applying the resin composition. By using a method for reinforcing a concrete structure including a step of attaching a reinforcing fiber material to the surface of the concrete structure, and a step of curing the resin composition to integrate the concrete structure and the reinforcing fiber material, Various reinforcing fiber materials can be reinforced and integrated with the surface of a concrete structure in a wet or flooded state without causing problems such as poor adhesion of the resin and the reinforcing fiber material, peeling, and strength deterioration. For this reason, it is possible to save the time and effort for the construction such as drying of the concrete surface, and to shorten the construction period because it is not affected by the weather.

Therefore, it is possible to quickly reinforce the concrete structure in the waterside area such as the breakwater, the seawall, the quay, the seawall, the embankment, the jetty, the tower, and the dam. In addition, it has excellent durability over time and has the advantage of saving maintenance work.

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Claims (11)

[Claims] 1. A step of pretreating the surface of a concrete structure, and a step of applying a resin composition that hardens in the presence of water to the surface of the pretreated concrete structure,
A method for reinforcing a concrete structure, comprising: a step of attaching a reinforcing fiber material to the surface of a concrete structure coated with the resin composition; and a step of curing the resin composition to integrate the concrete structure and the reinforcing fiber material. . 2. The method for reinforcing a concrete structure according to claim 1, wherein a resin composition containing a polysulfide-modified resin is used. 3. The method for reinforcing a concrete structure according to claim 1, wherein a resin composition containing a curing agent having 3 to 15 carbon atoms is used. 4. The method for reinforcing a concrete structure according to claim 3, wherein the curing agent is used by being encapsulated in microcapsules. 5. The method for reinforcing a concrete structure according to claim 3, wherein the hardening agent is supported on an inorganic material having fine pores and used. 6. The method for reinforcing a concrete structure according to claim 1, wherein a resin composition containing a surfactant is used. 7. The method for reinforcing a concrete structure according to claim 1, wherein a woven fabric, a mesh, a knitted fabric or a non-woven fabric of reinforcing fibers is used as the reinforcing fiber material. 8. The method for reinforcing a concrete structure according to claim 1, wherein an FRP plate is used as the reinforcing fiber material. 9. The method for reinforcing a concrete structure according to claim 1, wherein a reinforcing fiber material having a tensile strength in the range of 500 to 5,000 MPa is used. 10. A concrete structure reinforced by the method according to claim 1. 11. A concrete breakwater, seawall, quay, revetment, embankment, jetty, tower body or dam reinforced by the method according to any one of claims 1 to 9.