JP5478651B2 - Reinforcing method and reinforcing structure for concrete structure, and elastic layer forming material for reinforcing concrete structure - Google Patents

Description

  The present invention uses a sheet-like or plate-like reinforcing fiber-containing material containing continuous reinforcing fibers (hereinafter referred to as “fiber sheet”), and is used for beams and girders, as well as walls, columns, floor slabs. Reinforcement method and reinforcement structure of concrete structure that repairs and reinforces concrete structures such as slab members such as buildings and civil engineering structures (hereinafter simply referred to as “reinforcement”), and elastic layer for reinforcing concrete structures It relates to a forming material.

  In recent years, as a method of reinforcing an existing or new concrete structure, carbon fiber sheet bonding in which a continuous reinforcing fiber sheet such as a carbon fiber sheet or an aramid fiber sheet as a fiber sheet is attached to or wound around the surface of the concrete structure. There are a continuous fiber sheet bonding method such as a method and an aramid fiber sheet bonding method, or a method in which a fiber sheet obtained by impregnating a continuous fiber bundle with an uncured matrix resin is bonded and cured.

  Furthermore, an FRP plate adhesion reinforcing method has been developed in which a factory-produced FRP plate having a thickness of 1 to 5 mm and a width of about 5 to 10 cm is bonded to the concrete surface using a putty-like adhesive resin in order to omit on-site resin impregnation. .

  As long as the fiber sheet is bonded integrally with the concrete structure, the concrete structure subjected to such a reinforcing method can obtain a high reinforcing effect by the fiber sheet. However, if the concrete structure is deformed by a load or the like and the fiber sheet is peeled off from the surface of the concrete structure before it breaks, the intended purpose may not be achieved.

  Furthermore, in order to reinforce a concrete structure in which bending and shearing forces are generated, it is necessary to suppress cracks that occur as well as the effects of edge peeling.

  That is, for example, in an old concrete structure or a bridge that is an old concrete structure through which a heavy vehicle such as a truck passes, the number of fiber sheets to be laminated becomes large, and the problem of edge separation becomes important. Furthermore, in concrete structures that generate bending and shearing forces, cracks may occur due to bending moments and shearing forces, but these cracks must be restrained (crack width suppression), and crack dispersibility should be improved. is necessary.

Patent Documents 1 and 2 describe a method in which a buffer layer is provided on the surface of a concrete structure, and then a fiber sheet is bonded with an adhesive to reinforce. In addition, as the buffer material layer, a resin such as a thermosetting resin or a thermoplastic resin can be used, and this resin has an elongation at the maximum tensile load at 23 ° C. of 10 to 10 when cured alone. It is disclosed that 200%, the tensile strength is 0.1 to 50 N / mm ² , and the tensile modulus is 0.1 to 50 N / mm ² .

Japanese Patent No. 3415107 Japanese Patent No. 3977719

  However, as a result of the research experiments by the present inventors, when the epoxy-based cushioning material used as the cushioning material described in Patent Documents 1 and 2 above is used, the fixing strength and bending strength for the concrete structure It turned out that it was not enough in terms of (yield strength) and toughness.

  That is, in the reinforcing methods of Patent Documents 1 and 2, the standard of the tensile elastic modulus of the resin forming the buffer layer is low, and if it is reinforced with a continuous fiber sheet having high rigidity, the stress cannot be transmitted. It was found that there was a possibility, i.e. in this case it was not reinforced.

  Therefore, the object of the present invention is to greatly suppress the peeling of the fiber sheet from the surface of the concrete structure before reaching the breaking strength, to restrain the cracks, and to improve the crack dispersibility. A reinforcing method and a reinforcing structure for a concrete structure capable of improving the fixing strength, bending strength (yield strength) and toughness of the concrete structure, and an elastic layer forming material for reinforcing a concrete structure It is.

  Another object of the present invention is to improve edge peeling even in the case of a large number of fiber sheets to be laminated in a concrete structure where bending and shearing force is generated, and to generate bending moment and shearing. It is possible to suppress the occurrence and expansion of cracks by force, improve the crack dispersibility, and improve the fixing strength, bending strength (proof stress) and toughness of the concrete structure. A reinforcing method, a reinforcing structure, and an elastic layer forming material for reinforcing a concrete structure are provided.

The above object is achieved by the concrete structure reinforcing method and the reinforcing structure according to the present invention, and the elastic layer forming material for reinforcing a concrete structure. In summary, according to the first aspect of the present invention, in a method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated,
The fiber sheet is bonded onto the surface of the concrete structure via an elastic layer,
The elastic resin forming the elastic layer has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, and a tensile elastic modulus of 60 N / mm ² or more and 500 N / hour at a temperature of −10 ° C. to 50 ° C. mm ² or less, 0 span plastic elongation is 3 mm or more,
An effective adhesion length of the fiber sheet is 200 mm or more, and a method for reinforcing a concrete structure is provided.

According to the second aspect of the present invention, in the method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated,
(A) After applying a primer on the surface of the concrete structure, applying an elastic resin and curing to form an elastic layer;
(B) adhering the fiber sheet to the surface of the concrete structure on which the elastic layer is formed with an adhesive;
Have
The elastic resin has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, a tensile elastic modulus of 60 N / mm ² or more and 500 N / mm ² or less, at a temperature of −10 ° C. to 50 ° C., 0 Span plastic elongation is 3mm or more,
An effective adhesion length of the fiber sheet is 200 mm or more, and a method for reinforcing a concrete structure is provided.

According to the third aspect of the present invention, in the method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated,
(A) a step of applying an elastic resin to the surface of the fiber sheet impregnated and cured to cure and forming an elastic layer;
(B) bonding the fiber sheet to the surface of the concrete structure with an adhesive via the elastic layer;
Have
The elastic resin has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, a tensile elastic modulus of 60 N / mm ² or more and 500 N / mm ² or less, at a temperature of −10 ° C. to 50 ° C., 0 Span plastic elongation is 3mm or more,
An effective adhesion length of the fiber sheet is 200 mm or more, and a method for reinforcing a concrete structure is provided.

In the second and third inventions, the adhesive used in the step (b) is a room temperature curing type epoxy resin, epoxy acrylate resin, acrylic resin, MMA resin, vinyl ester resin, unsaturated polyester resin, or It is a photocurable resin. The epoxy resin adhesive is provided by a two-component type of a main agent and a curing agent,
(I) Main agent: An epoxy resin is used as a main component, and a material containing a silane coupling agent or the like as the adhesion enhancing agent is used.
(Ii) Curing agent: Contains amines as a main component, and the amine equivalent ratio of each of the main epoxy resin: curing agent is 1: 1.
With composition.

In the first to third aspects of the present invention, the elastic resin is a polyurea resin putty agent or a urea urethane resin agent. The polyurea resin putty agent contains a main agent, a curing agent, a filler, and an additive,
(I) Main agent: A prepolymer having an isocyanate as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt%.
(Ii) Curing agent: A curing agent containing an aromatic amine as a main component is used, and an NCO: amine ratio of the main agent calculated at 1.0: 0.55 to 0.99 parts by weight is used.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.
With composition.

  In the first to third aspects of the present invention, the fiber sheet is laminated and bonded to the surface of the structure in a plurality of layers, and is integrated with the structure. At this time, the elastic resin is applied and cured between the laminated fiber sheets to form an elastic layer.

  In the first to third aspects of the present invention, the fiber sheet is a fiber sheet in which continuous reinforcing fibers arranged in one direction are fixed to each other with a wire fixing material. The fiber sheet is a fiber sheet in which continuous reinforcing fibers are impregnated with a resin and the resin is cured. That is, the fiber sheet can be a single-layer or multi-layer FRP plate in which fibers are arranged in one direction or a plurality of directions. Further, the fiber sheet is a fiber in which reinforcing fibers are impregnated with a matrix resin, a plurality of cured continuous fiber reinforced plastic wires are arranged in a slender shape in the longitudinal direction, and the wires are fixed to each other with a wire fixing material. It can be a sheet. Further, a fiber sheet in which the resin is impregnated between the fiber reinforced plastic wires and the resin is cured, that is, an FRP plate can be obtained.

According to a fourth aspect of the present invention, in the method for reinforcing a concrete structure according to any one of the above, the elastic layer forming material for reinforcing a concrete structure comprising the polyurea resin putty agent forming the elastic layer,
The polyurea resin putty agent includes a main agent, a curing agent, a filler, an additive,
(I) Main agent: A prepolymer having an isocyanate as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt%.
(Ii) Curing agent: A curing agent containing an aromatic amine as a main component is used, and an NCO: amine ratio of the main agent calculated at 1.0: 0.55 to 0.99 parts by weight is used.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.
An elastic layer forming material for reinforcing a concrete structure is provided.

According to the fifth aspect of the present invention, there is provided a reinforcing structure for reinforcing a concrete structure,
At a temperature of −10 ° C. to 50 ° C., the tensile elongation at the time of curing is 400% or more, the tensile strength is 8 N / mm ² or more, and the tensile elastic modulus is 60 N / The fiber sheet layer impregnated with the resin is integrated with an adhesive through an elastic layer having a mm ² or more and 500 N / mm ² or less, a zero-span plastic elongation of 3 mm or more, and an effective adhesion length of the fiber sheet of 200 mm or more. There is provided a reinforcing structure of a concrete structure characterized by being bonded. The elastic resin is a polyurea resin putty agent or a urea urethane resin agent. The polyurea resin putty agent contains a main agent, a curing agent, a filler, and an additive,
(I) Main agent: A prepolymer having an isocyanate as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt%.
(Ii) Curing agent: A curing agent containing an aromatic amine as a main component is used, and an NCO: amine ratio of the main agent calculated at 1.0: 0.55 to 0.99 parts by weight is used.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.
With composition.

  According to the present invention, the fiber sheet can be greatly prevented from peeling off from the surface of the concrete structure before reaching the breaking strength, cracks can be restrained, and crack dispersibility can be improved. Further, the fixing strength, bending strength (yield strength) and toughness of the concrete structure can be improved.

  Furthermore, according to the present invention, in a concrete structure where bending and shearing force is generated, even when the number of fiber sheets to be laminated becomes large, the end peeling is improved, and the generated bending moment and shearing are improved. It restrains the occurrence and expansion of cracks by force, that is, it suppresses crack width and improves crack dispersibility, and improves the fixing strength, bending strength (proof stress) and toughness of concrete structures. Can be planned

It is sectional drawing of the reinforced concrete structure for demonstrating the reinforcement method of the concrete structure of this invention, and a reinforcement structure. It is a figure which shows one Example of the fiber sheet which can be used for the reinforcement method of the concrete structure of this invention. It is a figure which shows the other Example of the fiber sheet which can be used for the reinforcement method of the concrete structure of this invention. It is a perspective view which shows the other Example of the fiber sheet which can be used for the reinforcement method of the concrete structure of this invention. It is sectional drawing of the fiber reinforced plastic wire which comprises the fiber sheet which can be used for the reinforcement method of the concrete structure of this invention. It is a perspective view which shows the other Example of the fiber sheet which can be used for the reinforcement method of the concrete structure of this invention. It is process drawing explaining one Example of the reinforcement method of the concrete structure of this invention. It is a figure explaining the other Example of the reinforcement method of the concrete structure of this invention. It is a figure explaining the structure of the bending strength test apparatus for demonstrating the reinforcement method of the concrete structure of this invention, Fig.9 (a) is front sectional drawing, FIG.9 (b) and (c) are FIG. It is side surface sectional drawing. It is a figure which shows the bending test result of the reinforced concrete structure for comparing this invention with a comparative example. It is a figure explaining the structure of the adhesion test apparatus for demonstrating the reinforcement method of the concrete structure of this invention, Fig.11 (a) is a front view, FIG.11 (b) is a top view, FIG. (C) is a side view. It is a figure which shows the adhesion test result of the reinforced concrete structure for comparing this invention with a comparative example. It is a figure which shows the adhesion test result for demonstrating the effective adhesion length of the reinforced concrete structure for comparing this invention with a comparative example. It is a figure which shows the crack followability test result for demonstrating the crack followability of the elastic layer formed in the concrete structure for comparing this invention with a comparative example. It is process drawing explaining the other Example of the reinforcement method of the concrete structure of this invention.

  Hereinafter, a concrete structure reinforcing method and a reinforcing structure according to the present invention, and an elastic layer forming material for reinforcing a concrete structure will be described in more detail with reference to the drawings.

Referring to FIGS. 1A and 1B, according to the method for reinforcing a concrete structure according to the present invention, the concrete structure 100 has continuous reinforcing fibers f on its surface 102 via an elastic layer 104. The fiber sheet 1 containing it is adhere | attached and integrated. According to the present invention, the elastic resin forming the elastic layer 104 has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, and a tensile modulus of 60 N at a temperature of −10 ° C. to 50 ° C. / Mm ² or more and 500 N / mm ² or less, the 0 span plastic elongation is 3 mm or more, and the effective adhesion length of the fiber sheet 1 is 200 mm or more.

Furthermore, as shown in FIG. 1 (a), one feature of the method for reinforcing a concrete structure according to the present invention is a method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated. In
(A) After applying the primer 103 to the surface of the concrete structure 100, applying an elastic resin and curing it to form the elastic layer 104;
(B) a step of adhering the fiber sheet 1 with an adhesive 105 to the surface of the concrete structure 100 on which the elastic layer 104 is formed;
Have
The elastic resin has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, a tensile modulus of 60 N / mm ² or more and 500 N / mm ² or less, 0 span at a temperature of −10 ° C. to 50 ° C. The plastic elongation is 3 mm or more, and the effective adhesion length of the fiber sheet 1 is 200 mm or more.

As shown in FIG. 1 (b), another feature of the method for reinforcing a concrete structure according to the present invention is a method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated.
(A) a step of applying an elastic resin to the surface of the fiber sheet 1 impregnated and cured with the resin 105a and curing to form the elastic layer 104;
(B) bonding the fiber sheet 1 to the surface of the concrete structure 100 with the adhesive 105 via the elastic layer 104;
Have
The elastic resin has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, a tensile modulus of 60 N / mm ² or more and 500 N / mm ² or less, 0 span at a temperature of −10 ° C. to 50 ° C. The plastic elongation is 3 mm or more, and the effective adhesion length of the fiber sheet 1 is 200 mm or more.

That is, in the present invention, the tensile elongation at the time of curing is 400% at a temperature of −10 ° C. to 50 ° C. formed on the surface of the concrete structure 100 with an elastic resin such as a polyurea resin putty agent or a urea urethane resin agent. As described above, the tensile strength is 8 N / mm ² or more, the tensile modulus is 60 N / mm ² or more and 500 N / mm ² or less, the 0-span plastic elongation is 3 mm or more, and the effective adhesion length of the fiber sheet 1 is 200 mm or more. A reinforcing structure 200 of a concrete structure in which a fiber sheet layer 106 impregnated with a resin is integrally bonded with an adhesive 105 through a layer 104 is provided.

Example 1
Next, a concrete structure reinforcing method and a reinforcing structure according to the present invention and a first embodiment of an elastic layer forming material for reinforcing a concrete structure will be described.

  First, each material used in the present invention will be described.

(Fiber sheet)
In the present invention, various forms of fiber sheets 1 can be used. Although the Example of the fiber sheet 1 is concretely demonstrated as the specific examples 1-3, the form of the fiber sheet 1 used by this invention is not limited to what is shown to these specific examples.

Example 1
FIG. 2 shows an embodiment of the fiber sheet 1 that can be used in the present invention. The fiber sheet 1 is a non-resin-impregnated fiber sheet 1A configured in a sheet shape by aligning continuous reinforcing fibers f in one direction.

That is, 1 A of fiber sheets can be set as the structure which hold | maintained the reinforcing fiber sheet which consists of the continuous reinforcing fiber f arranged in one direction with the wire fixing material 3 used as a mesh-like support body sheet | seat. For example, when carbon fibers are used as the reinforcing fibers f, for example, a plurality of unimpregnated single fiber bundles in which 6000 to 24000 single fibers (carbon fiber monofilaments) f having an average diameter of 7 μm are converged in parallel in one direction. Used to align. The fiber basis weight of the carbon fiber sheet 1A is usually 30 to 1000 g / m ² .

  Carbon obtained by impregnating the surfaces of the warp yarn 4 and the weft yarn 5 constituting the mesh-like support sheet as the wire fixing material 3 in advance with a low melting point type thermoplastic resin, and arranging the mesh-like support sheet 3 in a sheet shape The fibers are laminated on one or both sides of the fiber and heated and pressed to weld the warp 4 and weft 5 portions of the mesh-like support sheet 3 to the carbon fiber sheet.

  In addition to the biaxial configuration, the mesh-shaped support sheet 3 is formed by orienting glass fibers in three axes, or only the wefts 5 orthogonal to the carbon fibers arranged in one direction. It can also be bonded to the so-called uniaxially oriented carbon fibers that are arranged and aligned in the form of a sheet.

  As the yarn of the wire fixing material 3, for example, a double-structured composite fiber having a glass fiber in the core and a low-melting-point heat-fusible polyester around it is also preferably used. .

Example 2
Further, as shown in FIG. 3, the fiber sheet 1 is obtained by impregnating a resin Re into a reinforcing fiber sheet 1 in which a plurality of continuous reinforcing fibers f are aligned in one direction, for example, a fiber sheet 1A as shown in FIG. Further, a fiber sheet (so-called FRP plate) 1B in which the resin is cured can be used. Of course, the fiber sheet 1B may be an FRP plate having a thickness of about 0.5 to 10 mm, which is composed of a single layer or a plurality of layers in which fibers are arranged in one direction or a plurality of directions.

  In the fiber sheets 1A and 1B described in the specific examples 1 and 2, the reinforcing fiber f is not limited to carbon fiber, but glass fiber, basalt fiber; metal fiber such as boron fiber, titanium fiber, and steel fiber. Furthermore, organic fibers such as aramid, PBO (polyparaphenylene benzbisoxazole), polyamide, polyarylate, polyester, and high-strength polyester can be used alone or in a mixture of plural kinds. .

  In addition, as the resin Re in the case of the fiber sheet 1B in the specific example 2, a thermosetting resin or a thermoplastic resin can be used. As the thermosetting resin, a room temperature curing type or a thermosetting type epoxy resin can be used. Vinyl ester resin, MMA resin, acrylic resin, unsaturated polyester resin, phenol resin, and the like are preferably used, and epoxy resin, nylon, vinylon, and the like can be suitably used as the thermoplastic resin. The fiber volume content (Vf) is 40 to 75%, preferably 50 to 70%.

Example 3
Further, as shown in FIGS. 4 and 5, the fiber sheet 1 has a plurality of continuous fiber reinforced plastic wires 2 having a small diameter, which are impregnated with the matrix resin R and cured, and are arranged in a slender shape in the longitudinal direction. Moreover, the fiber sheet 1C which fixed each wire 2 with the wire fixing material 3 mutually can also be used.

  The fiber reinforced plastic wire 2 has a substantially circular cross-sectional shape (FIG. 5A) having a diameter (d) of 0.5 to 3 mm, or a width (w) of 1 to 10 mm and a thickness (t) of 0. A substantially rectangular cross-sectional shape (FIG. 5B) of 1 to 2 mm can be obtained. Of course, other various cross-sectional shapes can be used as necessary.

  As described above, in the fiber sheet 1 that is aligned and slid in one direction, the wires 2 are close to and separated from each other by a gap (g) = 0.05 to 3.0 mm. Fixed. In addition, the length (L) and width (W) of the fiber sheet 1C formed in this way are appropriately determined according to the size and shape of the structure to be reinforced. The total width (W) is 100 to 1000 mm. Moreover, although the length (L) can manufacture a strip-shaped thing about 1-5 m, or a thing 100 m or more, it cuts and uses it suitably at the time of use.

  It is also possible to manufacture the fiber sheet 1C with a length (L) of about 1 to 5 m and a width W of about 1 to 10 m longer than this.

  Even in the case of the fiber sheet 1C, as the reinforcing fiber f, carbon fiber, glass fiber, basalt fiber; metal fiber such as boron fiber, titanium fiber, steel fiber; and aramid, PBO (polyparaphenylene benzbisoxazole) Organic fibers such as polyamide, polyarylate, polyester, and high-strength polyester can be used alone or in a mixture of plural kinds. The matrix resin R impregnated in the fiber reinforced plastic wire 2 can be a thermosetting resin or a thermoplastic resin. As the thermosetting resin, a room temperature curing type or a thermosetting type epoxy resin, A vinyl ester resin, an MMA resin, an acrylic resin, an unsaturated polyester resin, a phenol resin, or the like is preferably used, and an epoxy resin, nylon, vinylon, or the like can be preferably used as the thermoplastic resin. The fiber volume content (Vf) is 40 to 75%, preferably 50 to 70%.

  Further, as a method of fixing each wire 2 with the wire fixing material 3, for example, as shown in FIG. 4, a plurality of wires arranged in a sag-like manner using wefts as the wire fixing material 3 are arranged. It is possible to adopt a method of driving and knitting a wire rod in the form of a sheet consisting of two, that is, a continuous wire rod sheet at a constant interval (P) perpendicular to the wire rod. The driving interval (P) of the weft yarn 3 is not particularly limited, but is usually selected in the range of 10 to 100 mm in consideration of the handleability of the produced fiber sheet 1.

  At this time, the weft 3 is, for example, a yarn obtained by bundling a plurality of glass fibers or organic fibers having a diameter of 2 to 50 μm. As the organic fiber, nylon, vinylon, polyester or the like is preferably used.

  As another method of fixing each wire 2 in a slender shape, a mesh-like support sheet can be used as the wire fixing member 3 as shown in FIG.

  That is, the above-mentioned specific example in which a plurality of wire rods 2 arranged in the form of a sheet in a sheet form, that is, one side or both sides of a wire sheet is made of glass fiber or organic fiber having a diameter of 2 to 50 μm, for example. 1 may be configured to be supported by a mesh-like support sheet 3 having the same configuration as described in 1.

  Furthermore, as another method of fixing each wire 2 in a slender shape, as shown in FIG. 6 (b), as the wire fixing material 3, for example, a flexible belt material such as an adhesive tape or an adhesive tape is used. Can be used. The flexible strip 3 has one side or both sides of a plurality of fiber reinforced plastic wires 2 in a direction perpendicular to the longitudinal direction of each fiber reinforced plastic wire 2 arranged in the form of a sheet. Paste and fix.

  That is, as the flexible strip 3, an adhesive tape or adhesive tape such as a vinyl chloride tape, a paper tape, a cloth tape, and a nonwoven fabric tape having a width (w1) of about 2 to 30 mm is used. These tapes 3 are usually stuck in a direction perpendicular to the longitudinal direction of each fiber reinforced plastic wire 2 at intervals (P) of 10 to 100 mm.

  Furthermore, as the flexible strip 3, the thermoplastic resin such as nylon or EVA resin is formed into a strip and is heat-bonded to one side or both sides in the direction perpendicular to the longitudinal direction of the wire 2. Is done.

(Reinforcing method)
Next, a method for reinforcing a concrete structure will be described with reference to FIG. According to the present invention, the concrete structure is reinforced using the fiber sheet 1 manufactured as described above.

  That is, according to the method for reinforcing a concrete structure of the present invention, for example, as the fiber sheet 1, the continuous fiber reinforced plastic wire 2 having a small diameter and impregnated with the matrix resin R and cured as described in the specific example 3 is used. It is possible to use a fiber sheet 1C in which a plurality of wires are arranged in a slender shape in the longitudinal direction and each wire 2 is fixed to each other with a wire fixing material 3, and on the elastic layer 104 formed on the surface of the concrete structure. The adhesive 105 is bonded and integrated. At this time, for example, when the fiber sheet 1A described in the specific example 1 is used, the fiber sheet 1A is impregnated with the resin (matrix resin) simultaneously with the adhesive of the fiber sheet 1A to the concrete structure. Can also be done.

  Thereby, the reinforcement structure 200 of the concrete structure which has the elastic layer 104 and the fiber sheet layer 106 to which the fiber sheet 1 impregnated with the resin is bonded is formed.

  When reinforcing the concrete structure 100, for members (structures) that mainly receive bending moment and axial force, the orientation direction of the reinforcing fibers is generally aligned with the principal stress direction of tensile stress or compression stress generated by the bending moment. By bonding, it is possible for the fiber sheet 1 to effectively bear the stress and to efficiently improve the load resistance of the structure.

  When bending moments act in two orthogonal directions, two or more fiber sheets 1 are orthogonally laminated and bonded so that the orientation direction of the reinforcing fibers f of the fiber sheet 1 substantially coincides with the principal stress generated by the bending moment. By doing so, the load bearing capacity can be improved efficiently.

  With reference to FIG. 7, the reinforcement method of the concrete structure in a present Example is demonstrated further more concretely.

(First step)
As shown in FIGS. 7A and 7B, the weakened portion 101a of the surface to be reinforced (that is, the surface to be bonded) 101 of the concrete structure 100 is ground with a disk sander, sand blast, steel shot blast, water jet or the like. The surface treatment is performed so that the surface 102 is removed by the means 50 and the surface fragile layer is removed from the adherend surface 101 of the concrete structure 100.

(Second step)
A primer 103 is applied to the surface 102 subjected to the ground treatment (FIG. 7C). The primer 103 is appropriately selected according to the material of the elastic layer 104 (FIG. 7 (d)) and the reinforced concrete structure 100, such as urethane resin primer such as urethane resin primer, epoxy resin system, and MMA resin system. The

In particular, according to the present invention, a primer having the following composition (hereinafter referred to as “concrete surface primer”) can be preferably used. That is, the concrete surface primer is composed of a two-component type of a main agent and a curing agent,
(I) The main agent includes various solvents for adjusting viscosity, and additives for improving adhesion and impregnation to the prepolymer mainly composed of tolylene diisocyanate.
(Ii) The curing agent contains an epoxy polyol as a main component and includes a filler, a foam breaker, a colorant, a solvent for adjusting the viscosity, and the like.
(Iii) Here, the above-mentioned two liquids (main agent, curing agent) are mixed, applied and used, and adjusted so as to have 20 to 30% residual hydroxy groups after the curing reaction of the main agent and curing agent.
With composition.

  Primer for concrete surface with the above composition increases viscosity by impregnation on the work surface due to the decrease in viscosity due to the solvent, and hydroxy group is used in various organic resin materials (adhesives) used in the next process. We will build a situation where hydrogen bonds will be firmly bonded to certain inorganic materials such as concrete.

  In addition, solvent volatilization is completed in about 1 hour, and can be applied to the next step immediately after application while leaving the reaction components.

  In addition, the application | coating process of the primer 103 can also be skipped depending on the case.

(Third step)
An elastic resin such as a polyurea resin putty agent or a urea urethane resin agent is applied to the surface 102 which has been subjected to the base treatment, and in this embodiment, a polyurea resin putty agent 104 is applied at a required thickness (T), and is cured by reaction to form an elastic layer. 104 is formed (FIG. 7D). The coating thickness (T) is appropriately set according to the unevenness on the surface of the adherend surface 102 and the thickness T of the fiber sheet 1, but is generally about T = 0.2 to 10 mm. In addition, the polyurea resin putty agent 104 is usually applied to the entire surface to be bonded 102, but may be partial in some cases.

The polyurea resin putty agent in this embodiment, that is, the elastic resin material (elastic layer forming material) forming the elastic layer 104 includes a main agent, a curing agent, a filler, an additive, and the like, and an example of the composition thereof If it shows, it will be as follows.
(I) Main agent: A prepolymer having an isocyanate (for example, 4, -4′diphenylmethane diisocyanate) as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt% is used.
(Ii) Curing agent: A curing agent containing an aromatic amine (for example, an amine value of 80 to 90) as a main component is used, and the NCO: amine ratio of the main agent is 1.0: 0.55 to 0.99 parts by weight. Use the calculated one. Furthermore, p-toluenesulfonate can also be included as a curing accelerator.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.

Here, the elastic resin, the polyurea resin putty agent used in this example, has a tensile elongation at curing of 400% or more (usually 400 to 600%) and a tensile strength of 8N at a temperature of −10 ° C. to 50 ° C. / Mm ² or more (usually 8 to 10 N / mm ² ), tensile modulus of 60 N / mm ² or more and 500 N / mm ² or less (usually 60 to 100 N / mm ² ), and 0 span plastic elongation of 3 mm or more and 25 mm or less. Is done.

If the tensile elongation at curing is less than 400%, the tensile strength is less than 8 N / mm ² , and the elastic modulus is less than 60 N / mm ² , the necessary reinforcing stress cannot be transmitted. Conversely, the tensile elongation at curing is 600%. When the tensile strength exceeds 10 N / mm ² and the elastic modulus exceeds 100 N / mm ² , particularly when it exceeds 500 N / mm ² , there is a problem that the elongation performance is insufficient.

Further, as described above, the 0 span plastic elongation is set to 3 mm or more and 25 mm or less at a temperature of −10 ° C. to 50 ° C. However, if the 0 span plastic elongation is less than 3 mm, the cracks generated in the concrete structure are not cracked. The effect of restraining and improving crack dispersibility is reduced. The reason why the 0-span plastic elongation is 25 mm or less is that it is technically difficult to manufacture a product having a tensile elastic modulus of 60 N / mm ^{2 and} a performance of 0-span plastic elongation of 25 mm or more.

  Moreover, in order to use polyurea resin as a putty agent, the viscosity at 2 revolutions by a BM type viscometer at 23 ° C. is 200 to 700 Pa · s, and at 20 revolutions, it is in the range of 60 to 100 Pa · s. It is desirable that the thixotropic index, that is, the ratio of the measured values of viscosity at different rotational speeds by a rotational viscometer (viscosity at 20 rotational speeds ÷ viscosity at 2 rotational speeds) is 4 to 7.

  That is, when the viscosity is less than 60 Pa · s and the thixotropic index is less than 4, sagging occurs after coating, and it becomes difficult to apply the smoothness of the coated surface and the ceiling surface and wall surface, and conversely, the viscosity is 100 Pa. If the thixotropic index is larger than s and exceeds 7, the resin is hard, there is a problem in mixing, and it is difficult to apply smoothly.

  Here, Table 1 below shows the epoxy resin putty agent conventionally used as the material for forming the buffer material layer described in Patent Document 1 and the material for forming the elastic layer used in the present invention. The result of having compared the physical property which the polyurea resin putty agent of the said composition has is shown.

  From the results of Table 1 above, it can be seen that when an epoxy resin putty agent is used, the fixing strength, bending strength (yield strength) and toughness cannot coexist and the reinforcing effect cannot be exhibited.

  On the other hand, polyurea resin putty can be used as an elastic layer forming material for reinforcing concrete structures to achieve delamination prevention and repair reinforcement effects, and increase fixing strength, bending strength (yield strength) and toughness. Thus, it was found that it can be used very suitably for the reinforcement method of concrete structures.

  In particular, the polyurea resin putty agent 104 having the above composition according to the present invention has a great effect of preventing cracks because the “0-span plastic elongation” reaches 3 to 4 mm and a maximum of 6 mm.

  The “0 span plastic elongation” refers to a displacement when the resin breaks and the proof stress is greatly reduced. The “0 span plastic elongation” is determined by the “crack followability test of elastic layer” described later.

  That is, even if the concrete structure is cracked by a bending moment or shearing force, and the crack width reaches 3 to 6 mm, the elastic layer 104 made of the polyurea resin putty agent does not break. Therefore, the putty agent (elastic layer) 104 transmits the force of the fiber sheet 1 to the concrete structure and achieves good reinforcement. Moreover, according to the reinforcing method of this invention, the dispersibility of a crack is favorable.

  Moreover, it turned out that the polyurea resin putty agent of the said composition has a softness | flexibility also in winter, and can achieve the favorable reinforcement | strengthening of a concrete structure. According to the results of our research experiments, it has been found that urea urethane resin agents can also exhibit the same performance as polyurea resin putty agents.

(4th process)
As shown in FIGS. 7E and 7F, when the polyurea resin putty is cured and the elastic layer 104 is formed, the adhesive 105 is applied on the elastic layer 104, and the fiber is applied to the surface. The sheet 1 is pressed and bonded to the surface 102 of the concrete structure 100 to be reinforced via an elastic layer 104.

  Examples of the adhesive 105 include a room temperature curable epoxy resin, an epoxy acrylate resin, an acrylic resin, an MMA resin, a vinyl ester resin, an unsaturated polyester resin, a photocurable resin, and the like. MMA resin is preferred.

In this example, an epoxy resin adhesive was used. For example, the epoxy resin adhesive is provided by a two-component type of a main agent and a curing agent, and an example of the composition is as follows.
(I) Main agent: An epoxy resin is used as a main component, and an adhesive enhancement imparting agent containing a silane coupling agent as required is used. The epoxy resin can be, for example, a bisphenol type epoxy resin, in particular, a rubber-modified epoxy resin for imparting toughness, and a reactive diluent and a thixotropic agent may be added depending on the application.
(Ii) Curing agent: containing amines as a main component, optionally containing a curing accelerator, and containing a colorant as an additive, the main component epichlorohydrin: the amine equivalent ratio of the curing agent is 1: 1. The amines can be aliphatic amines including, for example, metaxylene diamine and isophorone diamine.

  Although the adhesive 105 has been described as being applied on the elastic layer 104, it can of course be applied to the fiber sheet 1, and on both the surface of the elastic layer 104 and the adhesive surface of the fiber sheet 1. It may be applied.

  That is, in this embodiment, the fiber sheet 1 is bonded to the surface of the elastic layer 104, and in the present embodiment, for example, the fiber sheet 1C (the fiber sheet described as the specific example 3 shown in FIG. 4) is used. In the case where the gap (g) between the wires 2 and 2 is filled with resin, and in some cases, for example, in the case of the fiber sheet 1A shown in the specific example 1, the adhesive 105 is used as described above. Is impregnated as a resin (matrix resin) between the fibers f in the fiber sheet 1. The fiber sheet layer 106 formed by the resin-impregnated fiber sheet 1 and the elastic layer 104 constitute a reinforcing structure 200.

  Moreover, when there is much required reinforcement amount, it is possible to adhere | attach the multiple layers fiber sheet 1 on the structure surface. When the fiber sheets 1 having a plurality of layers are laminated and bonded, stress concentration occurs at the end portion, and the peel fracture resistance may be reduced. According to the present invention, when an elastic resin having the above characteristics is used, when a plurality of fiber sheets 1 are laminated and used, it is possible to suppress the end portions of the fiber sheets 1 from being peeled off. .

  In addition, in order to prevent peeling failure, as shown in FIG. 8, it is preferable to change the sheet length (L) (see FIG. 1) of the fiber sheet 1 of each layer. For example, the length of the fiber sheet 1 to be laminated in a plurality of layers is shortened in order as it goes to the outer layer that is separated from the structure surface 102, and the end portions 1a of the fiber sheet 1 are laminated stepwise. The shifting length (h) of the end portion 1a is suitably about 10 mm to 300 mm. For example, good results could be obtained by bonding the sheet end 1a so as to be shortened by 100 mm.

  That is, by reducing the length (L) of the fiber sheet 1 to be laminated in a plurality of layers by reducing the outer layer in order by about 10 to 300 mm and laminating the end 1a in a stepped manner, the stress concentration at the sheet end 1a is reduced, It is possible to improve the peeling resistance.

  As described above, according to the present invention, the fiber sheet 1 can be laminated and bonded to the surface of the structure in a plurality of layers and integrated with the structure. An elastic layer can also be formed by applying and curing an elastic resin 104 such as polyurea resin between these layers.

  Next, the following experiment was performed in order to demonstrate the effect of the reinforcing method and the reinforcing structure of a concrete structure and the elastic layer forming material for reinforcing a concrete structure according to the present invention.

Experimental example 1 (bending test)
In this experimental example, as shown in FIG. 9, the fiber sheet 1 is used to reinforce the RC beam specimen 100T as the concrete structure 100 according to the bonding method, and the fixing strength, bending strength (proof strength) and toughness are observed. A bending test was performed. In this experimental example, the fiber sheet 1 was the fiber sheet 1C having the configuration described as the specific example 3 with reference to FIG.

(RC specimen)
9A, 9B and 9C show the shape, dimensions, bar arrangement and loading status of the test specimen 100T. The specimen 100T has a length (L0) of 2200 mm, a width (W0) of 200 mm, and a height (H0) of 300 mm. As shown in the drawing, the main rebar D19 is adjacent to the lower surface of the specimen 100T. Moreover, the main reinforcing bar D13 was arrange | positioned adjacent to the upper surface, and the reinforcing bar (stirrup) D13 was arranged surrounding the main reinforcing bars D19 and D13.

  The fiber sheet 1 was affixed to the tensile side of the specimen 100T, and a bending loading experiment was performed. Specimen 100T was cast using early-strength Portland cement, and about 1 week after placement, fiber sheet 1 alone or fiber sheet 1 with application of polyurea resin 104 or the like was adhered, and further one week Cured above. The specimen span length (Ls) is 1600 mm, and the shear span ratio is 2.8. The load point interval (S) is 200 mm.

(Fiber sheet)
A fiber sheet (strand sheet) 1C (manufactured by Nippon Steel Materials Co., Ltd .: trade name (FSS-HT600 (high strength type)) having the structure described with reference to Fig. 4 was used as the fiber sheet 1. 600 g / m ² .

Various physical properties of the fiber sheet 1 are as follows.
Elastic modulus: 245 kN / mm ²
Tensile strength: 3400 N / mm ²
Elongation at break: 1.5%
Design thickness: 0.333mm

  The schematic configuration of the fiber sheet 1 is as follows. In other words, the fiber reinforced plastic wire 2 of the fiber sheet 1 is impregnated with a curable carbon fiber strand having an average diameter of 7 μm and a converging number of 12,000 as the reinforcing fiber f, impregnated with a room temperature curable epoxy resin as the matrix resin R, and cured. Made. The fiber volume content (Vf) is 60%, and the cured fiber reinforced plastic wire 2 has a circular cross section with a diameter (d) of 1.1 mm.

  The fiber reinforced plastic wire 2 obtained in this way was aligned in one direction and arranged in a slender shape, and then the polyester fiber was held as a weft 3 in a sheet form by plain weaving. The interval (P) between the wefts 3 was 50 mm. Further, the gap (g) between the wires 2 and 2 is set to 0.1 to 0.3 mm.

  The fiber sheet 1 used had a width W1 of 200 mm and a length (L1) of 1500 mm. The fiber sheet 1 was affixed to the lower surface adherend surface 102 of the specimen 100T.

(Test method)
First, in this experimental example, the lower surface of the specimen 100T was polished by shot blasting to obtain an appropriate rough surface. 0.15 kg / m ^{2 of} “primer for concrete surface” 103 having the above composition was applied on the surface 102 of the specimen 100T.

  After the primer 103 is dry to the touch, the polyurea resin putty having the above composition is formed with a spatula so as to have a thickness (T) of about 1 mm in order to form the elastic layer 104 with the coated surface as the back surface. The structure (specimen) was applied to 100T. At this time, the polyurea resin putty agent was not dripped by its own weight even after the application was completed, and adhered to the specimen 100T.

  The putty-like polyurea resin used as the resin for forming the elastic layer 104 had a viscosity of 600 Pa · s at 2 revolutions by a BM viscometer at 23 ° C. and 95 Pa · s at 20 revolutions.

  The thixotropic index (viscosity at 20 revolutions ÷ viscosity at 2 revolutions) was 6.32.

Next, the polyurea resin putty agent applied to the specimen surface 102 was dried (cured) to form the elastic layer 104. On the elastic layer 104, the epoxy resin having the above composition was applied at a coating amount of 0.4 kg / m ² (as an undercoat for each layer when a plurality of fiber sheets 1 are laminated). Next, after lightly pressing the fiber sheet 1 against the epoxy resin coated surface, a plastic roller having a width of 100 mm and a diameter of 10 mm was moved on the fiber sheet 1 while applying a pressing force of about 100 N.

  The epoxy resin is in a state of exuding from the gap g between each wire 2 of the fiber sheet 1 by rolling from the sheet 1 with a plastic roller, and stuck to the specimen 100T without any holding. It did not peel in the state.

  Fiber sheet reinforced concrete specimen (invention) 100T produced as described above, fiber sheet reinforced concrete specimen 100T (Comparative Example 1) that does not use a putty agent, and reinforced concrete without fiber sheet reinforcement (unreinforced) A three-point bending test with a distance between supporting points (Ls) of 1600 mm was performed on the specimen 100T (Comparative Example 2) using the test apparatus shown in FIG. As described above, the specimens of the present invention and Comparative Example 1 were produced with the same structure and materials except that the putty agent 104 was applied to the concrete specimen surface 102.

  The result of the bending test is shown in FIG. The following can be understood from FIG.

  That is, in the specification of Comparative Example 1, peeling failure occurred from the interface between the specimen 100T and the fiber sheet 1, and peeling occurred early before the load increased. This indicates a situation where reinforcement is not possible.

  In the specification of Comparative Example 2, fixing strength and bending strength (proof strength) are not obtained. This indicates a situation where reinforcement is not possible.

  On the other hand, in the case of the specification of the present invention using the polyurea resin putty agent of the present invention, the fixing strength and bending strength (yield strength) are increased, the bending at the time of the maximum load is large, and the specimen after reinforcement It can be seen that the toughness of the (concrete beam) is high.

  In addition, when a conventional epoxy resin putty agent is used as the putty agent, as shown as Comparative Example 3 in FIG. 10, it can be seen that the performance is located between the present invention and Comparative Example 2.

Experimental Example 2 (Adhesion test)
In this experimental example, the fiber sheet 1 used in Experimental Example 1 was bonded to the concrete structure specimen 100T according to the same bonding method as described above, and an adhesion test was performed.

(Experimental specimen)
The adhesion test between the concrete structure and the fiber sheet 1 is based on JSCE-543-2000. An outline of the experimental specimen 100T is shown in FIGS. 11 (a), (b), and (c).

  The test specimen was an integral type (B-type specimen) that is less prone to shift during construction, and the notched part 100T1 before loading was hit to separate the concrete. Instron 55R1185 type universal testing machine (maximum load 100 kN) was used for loading. The screw parts 100T2 at both ends of the test body were fastened and fixed with a dedicated jig, and loaded.

  In this experimental example, a carbon fiber sheet is wound around and fixed to the region on one side (left side in FIG. 11) of the experimental specimen 100T with the notch 100T1 as the center, and the other side of the experimental specimen 100T is secured. The adhesion state of the fiber sheet 1 and the specimen 100T in the region on the right side (right side in FIG. 11) was observed.

  The measurement was performed with load, mutation, and strain, and the potential difference between the load cell of the testing machine and the wire strain gauge was recorded in synchronization with a data logger.

  The test results are shown in FIG. From FIG. 12, in the case of using high-strength fibers for the fiber sheet 1, in Comparative Example 1 where the polyurea resin putty agent was not applied, the adhesion breakage of the fiber sheet 1 with respect to the specimen was reached before reaching the maximum load. is happening. On the other hand, when the polyurea resin putty agent of the present invention is applied and cured to have an elastic layer, concrete splitting fracture occurs, and the fixing strength and bending strength (yield strength) are significantly greater than those of the comparative examples. And can have toughness. In this experimental example, the difference was about twice. Moreover, when an epoxy resin putty agent is used, it turns out that it has the performance located between this invention and the comparative example 1 as shown as the comparative example 2 in FIG.

  Thus, it has been clarified that the concrete structure 100 can be effectively reinforced by the concrete structure reinforcing method and the reinforcing structure according to the present invention and the elastic layer forming material for reinforcing a concrete structure.

  “Effective adhesion length” refers to the length of a section in which the adhesion stress between the continuous fiber sheet and the concrete acts effectively at the maximum load until the continuous fiber sheet peels.

  FIG. 13 is a diagram illustrating the relationship between the strain position and the strain amount of the fiber sheet 1 at the maximum load.

  From FIG. 13, in the case of using high-strength fibers for the fiber sheet 1, in Comparative Example 1 where the polyurea resin putty agent was not applied, the adhesion breakage of the fiber sheet 1 with respect to the specimen was reached before reaching the maximum load. Has occurred and the effective deposition length is on the order of 100 mm. On the other hand, when the polyurea resin putty agent of the present invention is applied and cured to have an elastic layer, even if the concrete split fracture occurs, the adhesion breakage due to the fiber sheet does not occur, the effective adhesion length is It has reached about 300 mm. Moreover, when an epoxy resin putty agent is used, it turns out that it has the performance located between this invention and the comparative example 1 as shown as the comparative example 2 in FIG.

According to the results of the inventors' experiment, the effective adhesion length varies depending on the thickness and rigidity of the sheet. However, when the carbon fiber is 600 g / m ² per unit area, the effective adhesion length is 200 mm or more and 1000 mm or less to prevent peeling. It is effective. If the effective adhesion length is less than 200 mm, the region where the shearing force due to adhesion can be transmitted becomes small, and it becomes easy to peel and break early. The reason why the effective adhesion length is set to 1000 mm or less is that it is technically difficult to manufacture an article having a tensile elastic modulus of 60 N / mm ² or more and an effective adhesion length exceeding 1000 mm.

That is, as described above, according to the present invention, it can be seen that the fixing strength, bending strength (yield strength), and toughness can be significantly higher than those of the comparative example. Although the above description is an example of a carbon fiber sheet having a basis weight of 600 g / m ² , the effective adhesion length can be selected according to the tensile rigidity of the fiber sheet.

Experimental example 3 (crack following ability of elastic layer)
In this experimental example, as the elastic resin forming the elastic layer, the concrete when the polyurea resin putty agent and urea urethane resin putty agent used in Experimental Examples 1 and 2 and the epoxy resin putty agent as a comparative example are used. Experiments were conducted on the ability to follow cracks in structures.

  The crack followability test of the elastic layer covered with the concrete structure was performed according to JSCE-K532-2007.

(Test specimen)
The slate plate as a test body is mixed with cement and fiber with water, then scraped on the same principle as paper scooping using a round net-type paper machine (wet machine), placed on a template and press-cured, followed by curing. “JISA5430 (FB)” (trade name) manufactured by Nippon Test Panel Co., Ltd., which has been commercialized, was used.

  A slate plate having a size of 25 mm × 50 mm was polished from one end to a width of 25 mm and a length of 25 mm or more. The test body was formed by flatly arranging two slate plates by abutting the end portions on the polishing side and bonding the back surface with a gum tape.

An epoxy denatured primer (0.15 kg / m ² ) was applied to the entire polished surface of the slate plates joined together. After the primer was dry to the finger, the elastic resin was applied at a coating amount of 1.0 kg / m ² over a width of 25 mm and a length of 50 mm with the joint (seam) of the two slate plates as the center.

  Thereafter, the specimen was cured for 7 days to prepare a test specimen.

(Test method)
The test body was fixed to a tensile tester (Instron 55R1185 type universal tester) and pulled at a constant speed of 5 mm / min to obtain a load-displacement curve.

The above experiment was performed for each elastic resin at −20 ° C., 0 ° C., 23 ° C., 40 ° C., and 60 ° C. to obtain FIG. From this experimental result, at a temperature of -10 ° C. to 50 ° C., which is an elastic resin used in the present invention, the tensile elongation at curing is 400% or more, the tensile strength is 8 N / mm ² or more, and the tensile elastic modulus is 60 N. It can be seen that the polyurea resin putty agent and the urea urethane resin agent that are not less than / mm ^{2 and not} more than 500 N / mm ² have a 0-span plastic elongation of 3 mm or more at a temperature of −10 ° C. to 50 ° C.

  On the other hand, the comparative example is a case where a conventional epoxy resin putty agent is used as an elastic resin. Although it has the same performance as that of the present invention at a temperature around 20 ° C., it has zero span plasticity at lower and higher temperature regions. It can be seen that the elongation performance is significantly reduced.

As described above, according to the results of Experimental Examples 1 to 3, the elastic resin used in the reinforcing method of the present invention has a tensile elongation of 400% or more and a tensile strength of 8 N at a temperature of −10 ° C. to 50 ° C. / Mm ² or more, tensile elastic modulus is 60 N / mm ² or more and 500 N / mm ² or less, and zero-span plastic elongation is 3 mm or more, so that the effective adhesion length of the fiber sheet is 200 mm or more, which is much higher than before. It can have high fixing strength, bending strength (yield strength) and toughness, and even when cracks occur in the concrete structure, the force of the fiber sheet 1 is transmitted to the concrete structure to achieve good reinforcement. It was found that cracks were restrained and crack dispersibility was made good.

Example 2
Next, a concrete structure reinforcing method and a second embodiment of the reinforcing structure according to the present invention will be described with reference to FIG. In Example 1, according to the method for reinforcing a concrete structure of the present invention, a polyurea resin putty agent 104 was applied to the surface of the concrete structure 100 and cured to form an elastic layer, and then the elastic layer 104 was formed. The fiber sheet 1 was bonded to the surface of the concrete structure 100 with an adhesive 105.

  According to the present embodiment, as shown in FIG. 1 (b), the concrete structure reinforcement method uses the fiber sheet 1 described as specific examples 1 to 3 in the first embodiment. Such fiber sheet 1 is impregnated with resin 105a and cured, and a fiber-reinforced plastic material, so-called FRP, is used.

  A polyurea resin putty agent 104 is applied to the surface of the fiber sheet 1 impregnated with the resin and cured to form an elastic layer 104. Next, the fiber sheet 1 on which the elastic layer 104 is formed is bonded with an adhesive 105 so that the elastic layer 104 is positioned on the surface 102 side of the concrete structure 100.

  More specific description will be given with reference to FIG.

(First step)
As shown in FIGS. 15A and 15B, the weakened portion 101a of the surface to be reinforced (that is, the surface to be bonded) 101 of the concrete structure 100 is ground with a disk sander, sand blast, steel shot blast, water jet, or the like. The surface treatment is performed so that the surface 102 is removed by the means 50 and the surface fragile layer is removed from the adherend surface 101 of the concrete structure 100.

(Second step)
A primer 103 is applied to the surface 102 subjected to the ground treatment (FIG. 15C). The primer 103 is appropriately selected according to the material of the resin 105 and the reinforced concrete structure 100 such as an epoxy resin type and an MMA resin type without being limited to the urethane resin type. Of course, the “primer for a concrete surface” having the above-described composition described in Example 1 can be used.

  In addition, the application | coating process of the primer 103 can also be skipped depending on the case.

(Third step)
On the other hand, as the fiber sheet 1, a plurality of continuous fiber reinforced plastic wires 2 having a small diameter and impregnated with the matrix resin R and cured as described in the above specific example 3 are used in the longitudinal direction. The fiber sheet 1 </ b> C can be used in which the wire rods 2 are aligned with each other and fixed to each other with the wire rod fixing members 3. Furthermore, in this embodiment, the fiber sheet 1 is impregnated with the matrix resin 105a and cured.

  A polyurea resin putty agent 104 is applied to such a resin-impregnated and hardened fiber-reinforced plastic material at a required thickness (T), and is cured by reaction to form an elastic layer 104 (FIG. 15 (d)). . The coating thickness (T) is appropriately set according to the unevenness of the surface to be bonded 102 of the concrete structure 100 and the thickness T of the fiber sheet 1, but generally T = about 0.2 to 10 mm. . Moreover, although the polyurea resin putty agent 104 is normally apply | coated to the whole surface of the fiber sheet 1, depending on the case, it may be partial. Of course, as described above, when a plurality of fiber sheets 1 are laminated, the polyurea resin putty agent 104 may be applied and cured between the laminated fiber sheets 1 to form an elastic layer.

  The material (elastic layer forming material) for forming the elastic layer 104 used in this example is the polyurea resin putty agent having the above-described composition described in Example 1.

(4th process)
As shown in FIG. 15D, when the polyurea resin putty is cured and the elastic layer 104 is formed on the fiber sheet 1, an adhesive 105 is applied to the surface 102 of the concrete structure 100 to which the primer 103 is applied. The elastic layer 104 of the fiber sheet 1 is pressed against this surface, and the fiber sheet 1 is bonded to the surface 102 of the concrete structure 100 to be reinforced through the elastic layer 104.

  Examples of the adhesive 105 include the room temperature curable epoxy resin, epoxy acrylate resin, acrylic resin, MMA resin, vinyl ester resin, unsaturated polyester resin, and photocurable resin described in Example 1. Specifically, Room temperature curable epoxy resins and MMA resins are preferred.

  In this example, the epoxy resin adhesive having the above-described composition described in Example 1 was used.

  In order to demonstrate the effect of the reinforcing method and the reinforcing structure of the concrete structure according to the present example, the same experiment (Experimental Examples 1, 2, and 3) as described in Example 1 was performed. As in FIG. 1, it was revealed that the concrete structure 100 can be effectively reinforced.

DESCRIPTION OF SYMBOLS 1 Fiber sheet 2 Fiber reinforced plastic wire 3 Wire material fixing material (weft, mesh support sheet, flexible strip)
100 Concrete structure 100T Concrete structure specimen (experimental specimen)
DESCRIPTION OF SYMBOLS 103 Primer 104 Elastic layer 105 Adhesive 106 Fiber sheet layer 200 Reinforcing structure

Claims (17)

In a method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated,
The fiber sheet is bonded onto the surface of the concrete structure via an elastic layer,
The elastic resin forming the elastic layer has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, and a tensile elastic modulus of 60 N / mm ² or more and 500 N / hour at a temperature of −10 ° C. to 50 ° C. mm ² or less, 0 span plastic elongation is 3 mm or more,
A method for reinforcing a concrete structure, wherein an effective adhesion length of the fiber sheet is 200 mm or more. In a method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated,
(A) After applying a primer on the surface of the concrete structure, applying an elastic resin and curing to form an elastic layer;
(B) adhering the fiber sheet to the surface of the concrete structure on which the elastic layer is formed with an adhesive;
Have
The elastic resin has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, a tensile elastic modulus of 60 N / mm ² or more and 500 N / mm ² or less, at a temperature of −10 ° C. to 50 ° C., 0 Span plastic elongation is 3mm or more,
A method for reinforcing a concrete structure, wherein an effective adhesion length of the fiber sheet is 200 mm or more. In a method for reinforcing a concrete structure in which fiber sheets containing reinforcing fibers are bonded and integrated,
(A) a step of applying an elastic resin to the surface of the fiber sheet impregnated and cured to cure and forming an elastic layer;
(B) bonding the fiber sheet to the surface of the concrete structure with an adhesive via the elastic layer;
Have
The elastic resin has a tensile elongation at curing of 400% or more, a tensile strength of 8 N / mm ² or more, a tensile elastic modulus of 60 N / mm ² or more and 500 N / mm ² or less, at a temperature of −10 ° C. to 50 ° C., 0 Span plastic elongation is 3mm or more,
A method for reinforcing a concrete structure, wherein an effective adhesion length of the fiber sheet is 200 mm or more.   The adhesive used in the step (b) is a room temperature curable epoxy resin, epoxy acrylate resin, acrylic resin, MMA resin, vinyl ester resin, unsaturated polyester resin, or photocurable resin. The method for reinforcing a concrete structure according to claim 2 or 3. The adhesive used in the step (b) is a room temperature curing type epoxy resin, and this epoxy resin adhesive is provided by a two-component type of a main agent and a curing agent,
(I) Main agent: An epoxy resin is used as a main component, and a material containing a silane coupling agent or the like as the adhesion enhancing agent is used.
(Ii) Curing agent: Contains amines as a main component, and the amine equivalent ratio of each of the main epoxy resin: curing agent is 1: 1.
The method for reinforcing a concrete structure according to claim 2 or 3, wherein the composition has a composition.   The method for reinforcing a concrete structure according to claim 1, wherein the elastic resin is a polyurea resin putty agent or a urea urethane resin agent. The elastic resin is a polyurea resin putty agent, and the polyurea resin putty agent includes a main agent, a curing agent, a filler, and an additive,
(I) Main agent: A prepolymer having an isocyanate as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt%.
(Ii) Curing agent: A curing agent containing an aromatic amine as a main component is used, and an NCO: amine ratio of the main agent calculated at 1.0: 0.55 to 0.99 parts by weight is used.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.
It is set as a composition, The reinforcement method of the concrete structure of any one of Claims 1-5 characterized by the above-mentioned.   The said fiber sheet is laminated | stacked and adhere | attached on the surface of the said structure in multiple layers, and is integrated with the said structure, The concrete structure of any one of Claims 1-7 characterized by the above-mentioned. Reinforcement method.   The method for reinforcing a concrete structure according to claim 8, wherein an elastic layer is formed by applying and curing the elastic resin between layers of the laminated fiber sheets.   The concrete sheet according to any one of claims 1 to 9, wherein the fiber sheet is a fiber sheet in which continuous reinforcing fibers aligned in one direction are fixed to each other by a wire fixing material. Reinforcement method.   The method for reinforcing a concrete structure according to claim 10, wherein the fiber sheet is a fiber sheet in which continuous reinforcing fibers are impregnated with a resin and the resin is cured.   The fiber sheet is a fiber sheet in which reinforced fibers are impregnated with a matrix resin, and a plurality of cured continuous fiber reinforced plastic wires are aligned in a slender shape in the longitudinal direction, and the wires are fixed to each other by a wire fixing material. The method for reinforcing a concrete structure according to any one of claims 1 to 9, wherein:   The method for reinforcing a concrete structure according to claim 12, wherein the fiber sheet is a fiber sheet in which a resin is impregnated between the fiber reinforced plastic wires and the resin is cured. The method for reinforcing a concrete structure according to any one of claims 1 to 5, wherein the elastic layer forming material for reinforcing a concrete structure comprises a polyurea resin putty agent that forms the elastic layer,
The polyurea resin putty agent includes a main agent, a curing agent, a filler, an additive,
(I) Main agent: A prepolymer having an isocyanate as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt%.
(Ii) Curing agent: A curing agent containing an aromatic amine as a main component is used, and an NCO: amine ratio of the main agent calculated at 1.0: 0.55 to 0.99 parts by weight is used.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.
An elastic layer forming material for reinforcing a concrete structure, characterized by having a composition. A reinforcing structure for reinforcing a concrete structure,
At a temperature of −10 ° C. to 50 ° C., the tensile elongation at the time of curing is 400% or more, the tensile strength is 8 N / mm ² or more, and the tensile elastic modulus is 60 N / The fiber sheet layer impregnated with the resin is integrated with an adhesive through an elastic layer having a mm ² or more and 500 N / mm ² or less, a zero-span plastic elongation of 3 mm or more, and an effective adhesion length of the fiber sheet of 200 mm or more. Reinforced structure of concrete structure characterized by being bonded.   The reinforcing structure for a concrete structure according to claim 15, wherein the elastic resin is a polyurea resin putty agent or a urea urethane resin agent. The elastic resin is a polyurea resin putty agent, and the polyurea resin putty agent includes a main agent, a curing agent, a filler, and an additive,
(I) Main agent: A prepolymer having an isocyanate as a reaction component and having a terminal residual isocyanate adjusted to 1 to 16 parts by weight with NCO wt%.
(Ii) Curing agent: A curing agent containing an aromatic amine as a main component is used, and an NCO: amine ratio of the main agent calculated at 1.0: 0.55 to 0.99 parts by weight is used.
(Iii) Filler: Meteorite powder, a habit modifier, etc. are included, and are appropriately blended in an amount of 1 to 500 parts by weight.
(Iv) Additives: Colorants, viscosity modifiers, plasticizers and the like are included, and are appropriately blended in an amount of 1 to 50 parts by weight.
The reinforcing structure for a concrete structure according to claim 15, wherein the reinforcing structure is a composition.

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