Repair materials and repair methods for concrete structures

Abstract

To provide a repair member of a concrete structure that has sufficient repair strength, suppresses permeation to the concrete structure, and maintains water vapor permeability from the concrete structure, and can newly reconstruct an aqueous curable composition.SOLUTION: A repair member 10 of a concrete structure comprises a curable composition containing a silicate aqueous solution and a pozzolan active material with difference of electric conductivity of 0.4 mS / cm or more, a laminated base material 4 and a water proof moisture permeable layer 6 laminated over the laminated base material 4. The laminated base material 4 comprises a sheet-like member where multifilaments are interlaced in a multi-axis mesh-like manner and a resin fiber sheet member. The water proof moisture permeable layer 6 includes a component forming a silicone skeleton.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a repair member and a repair method for a concrete structure. [Background technology]

[0002] Concrete structures have the advantages of being high strength, easy to construct, durable, and inexpensive, so many concrete structures were built in Japan, especially during the period of rapid economic growth.

[0003] On the other hand, concrete structures can develop cracks over many years of use due to carbon dioxide from the atmosphere penetrating with moisture, causing carbonation, corrosion and expansion due to the penetration of chloride ions from sea breezes and antifreeze sprays, and expansion caused by the reaction of specific silica mineral aggregates with water. These cracks can cause pieces of concrete to spall, or due to the freezing of moisture that has soaked into the concrete.

[0004] In attempts to prevent such spalling and deterioration of concrete, Patent Documents 1 to 3 and the like propose impregnating a spall-preventing laminated substrate, which is a combination of a mesh sheet and a nonwoven fabric, with a curable composition to form a repair material; Patent Document 4 proposes using an inorganic curable composition; and Patent Document 5 proposes using a water repellent composition.

[0005] The ultimate goal is to maintain existing concrete structures in a condition that allows them to be used semi-permanently by implementing these concrete structure protection and spalling prevention methods once every 10 to 20 years. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-26238 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-019146 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-149929 [Patent Document 4] Japanese Patent Application Publication No. 2017-186825 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-193884 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] However, in the case of providing a water-repellent layer in contact with the concrete structure or in the case of a configuration in which a water-repellent layer is impregnated into the hardened product of the hardened composition, once application has been performed, the water-repellent components penetrate into the concrete, and therefore, even if an attempt is made to remove the repair member and perform reapplication, the water-repellent components inside the concrete reduce the adhesive strength of the aqueous hardening composition, making reapplication impossible.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a repair material and a repair method for concrete structures that have sufficient reinforcing strength, suppress water penetration into concrete structures, maintain water vapor permeability from the concrete structures, and allow for reapplication of a new aqueous hardening composition. [Means for solving the problem]

[0009] This application includes the following inventions: (1) A repair component for concrete structures, comprising a hardening composition containing a silicate aqueous solution and a pozzolan active substance having an electrical conductivity difference of 0.4 mS / cm or more, a laminated substrate, and a waterproof / moisture-permeable layer laminated on the laminated substrate, wherein the laminated substrate includes a sheet-like member in which multifilaments are combined in a multiaxial mesh form and a resin fiber sheet member, and the waterproof / moisture-permeable layer contains a component that forms a silicone skeleton.

[0010] (2) The waterproof and moisture-permeable layer of the concrete structure repair member described above contains at least one component selected from the group consisting of acrylic silicone and modified silicone.

[0011] (3) A repair member for a concrete structure as described above, wherein the waterproof and moisture-permeable layer has a water absorption rate of 75% or less and a water vapor permeability of 20% or more after immersion in water for 24 hours.

[0012] (4) A method for repairing a concrete structure, comprising the steps of: preparing a repair member by applying or impregnating a layered substrate with a composition containing a silicate aqueous solution and a pozzolan active substance having an electrical conductivity difference of 0.4 mS / cm or more; hardening the repair member; and applying a waterproof / breathable material to the surface of the repair member to form a waterproof / breathable layer, wherein the waterproof / breathable material forms a silicone skeleton.

[0013] (5) The method for repairing a concrete structure as described above, wherein the waterproof and moisture-permeable material contains at least one component selected from the group consisting of acrylic silicone and modified silicone. [Effects of the Invention]

[0014] The concrete structure repair member and repair method of the present invention have sufficient repair strength, suppress water penetration into the concrete structure, maintain water vapor permeability from the concrete structure, and allow for the re-application of a new aqueous hardening composition. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view showing an example of a method for repairing a concrete structure using a concrete structure repair member (two-layer structure+waterproof / moisture-permeable layer) of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing an example of a method for repairing a concrete structure using a concrete structure repair member (three-layer structure+waterproof / moisture-permeable layer) of the present invention. [Figure 3] 1 is a flow diagram showing an example of a concrete structure repair method of the present invention. [Figure 4] 1 is a diagram showing a repair base member used in the concrete structure repair method of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] <Repair materials> A repair member 10 according to an embodiment of the present invention is attached to a concrete structure 5 as shown in FIG. 1, for example, in order to repair the concrete structure 5.

[0017] The repair member of the present application comprises a curable composition, a laminated substrate 4, and a waterproof moisture-permeable layer 6. The curable composition and the laminated substrate 4 may exist separately, but at the time of repair, the curable composition is impregnated into the laminated substrate 4 as described below.

[0018] Such a repair member 10 can maintain the original fire resistance of the concrete structure while ensuring adhesive strength, and by improving waterproofing while ensuring moisture permeability, it is possible to maintain repair performance for a long period of time.

[0019] (Curable composition) The curable composition is applied to and / or impregnated into the layered base material 4. By applying and / or impregnating the layered base material 4 with the curable composition and then curing the curable composition, the concrete structure 5 and the repair member 10 can be bonded together, and by bonding the repair member 10 together, it is possible to prevent concrete pieces from peeling off from deteriorated portions of the concrete structure 5.

[0020] The viscosity of the curable composition at 25° C. is preferably 400 mPa·s to 3000 mPa·s. By adjusting the viscosity to such a level, it is possible to ensure the impregnation into the laminated substrate 4. It is also possible to prevent the curable composition from dripping when it is applied to the concrete structure 5.

[0021] The curable composition can be made of various materials, such as organic materials such as epoxy resin, polyurethane, polyurea, unsaturated polyester, phenolic resin, or a combination thereof, and inorganic materials such as cement slurry, gypsum, glass, etc. Among these, the use of inorganic materials can ensure the fire resistance of the concrete structure.

[0022] As the inorganic hardenable composition, a composition containing an aqueous solution of sodium silicate, potassium silicate, lithium silicate or a mixture thereof and a pozzolan active substance (hereinafter sometimes referred to as "geopolymer") is particularly preferred.

[0023] In particular, when sodium silicate and potassium silicate are applied to the surface of the concrete structure 5, they can produce a CSH gel with calcium hydroxide in the concrete, thereby strengthening the adhesive strength between the repair member 10 and the concrete structure 5.

[0024] In geopolymers, the difference in specific gravity between the liquid component consisting of an aqueous silicate solution and the solid component consisting of a pozzolanic active substance is smaller than the difference in specific gravity between the water and cement contained in cement slurry, so separation of components in the hardenable composition can be suppressed.

[0025] When geopolymers are used in hardenable compositions, the pozzolan active substance preferably has an electrical conductivity difference of at least 0.4 mS / cm, more preferably at least 0.7 mS / cm, and even more preferably at least 1.2 mS / cm.

[0026] Such a difference in electrical conductivity ensures sufficient reactivity with the silicate aqueous solution and increases the adhesive strength between the repair member 10 and the concrete structure 5. The difference in electrical conductivity here is an index related to the reactivity of the pozzolanic active substance induced by an alkaline substance, and refers to the difference in electrical conductivity of a saturated calcium hydroxide aqueous solution before and after the addition of the pozzolanic active substance, obtained by the evaluation method described below.

[0027] Pozzolanic active substances are substances that harden upon reaction of water with calcium oxide, calcium hydroxide, aluminum hydroxide, etc. Examples include silica dust, diatomaceous earth, talc, aerosil, white carbon, kaolin, metakaolin, activated clay, acid clay, etc. Of these, metakaolin is preferred.

[0028] The pozzolan active substance preferably has a silica content of 40% by weight or more, calculated as SiO2, based on the dry solid content of the cured product. The aluminum content derived from the pozzolan active substance, calculated as Al2O3, is preferably 20% to 40% by weight, based on the dry solid content of the cured product.

[0029] The pozzolanic active substance may be used as a powder as is, or may be activated by methods such as thermal spraying, pulverization / classification, or the action of mechanical energy. These methods may also be used in combination.

[0030] The thermal spraying method is the same as that used for ceramic coating. In this thermal spraying method, the material powder is preferably melted at a temperature of 2000 to 16000°C and sprayed at a speed of 30 to 800 m / s, and methods such as plasma spraying, high-energy gas spraying, and arc spraying are possible. The specific surface area of ​​the obtained powder is 0.1 m 2 / g~100m 2 / g is preferred.

[0031] Any known method can be used for the pulverization and classification. Specifically, pulverization methods include methods using a jet mill, a roll mill, a ball mill, etc. Classification methods include sieving, specific gravity, wind force, wet sedimentation, etc.

[0032] To apply mechanical energy, a ball media mill, a media agitation mill, a roller mill, etc. are used, and the applied mechanical energy is preferably 0.5 kWh / kg to 30 kWh / kg. By setting the mechanical energy in this range, the powder can be sufficiently activated and the load on the device can be reduced.

[0033] For example, the total content of sodium, potassium, lithium or a mixture thereof derived from the silicate aqueous solution in the geopolymer is preferably 5% by weight to 30% by weight in terms of MO (M is sodium, potassium and lithium) relative to the dry solid content of the hardened material obtained from the hardenable composition.

[0034] When an aqueous silicate solution is used, the numerical value n of the aqueous solution represented by the following mathematical formula is preferably 0.5 to 1.1, and more preferably 0.7 to 1.0.

[0035] n=S×M (S: number of moles of silicon contained in the aqueous solution, M: number of moles of alkali metal contained in the aqueous solution)

[0036] (Other ingredients) In addition to the above components, the curable composition may contain components disclosed in JP-A-2017-186825, JP-A-2017-226955, etc., and additives known in the art. Examples include fillers, modifiers, dispersants, curing time adjusters, pigments, antioxidants, polymer emulsions, etc. These are not particularly limited, and known substances can be used. The filler may be any of those commonly used as a filler.

[0037] Examples of additives include carbon, cellulose, mineral fine powder, and synthesized inorganic crystalline powder. Modifiers include various metal salts that can react with aqueous silicate solutions, such as light-burned magnesium oxide and zinc oxide. Polymer emulsions include acrylic rubber, styrene-butadiene rubber, and mixtures thereof. These additives can be used in any amount as long as they do not impair the intended function of the curable composition. In particular, the polymer emulsion is preferably blended so that the weight of the polymer solids is 3% to 10% by weight based on the total weight of the dry solids of the curable composition.

[0038] This improves the fluidity of the curable composition, improves the adhesive strength of the cured product, and suppresses drying shrinkage of the cured product.

[0039] (Laminated base material) The laminated base material 4 is constructed by laminating a sheet-like member in which multifilaments are combined in a multiaxial mesh shape and a resin fiber sheet-like member. For example, when the first layer 1 is a sheet-like member in which multifilaments are combined in a multiaxial mesh shape and the second layer 2 is a resin fiber sheet-like member, the laminated base material 4 is preferably constructed such that the first layer 1 and the second layer 2 are laminated in this order from the concrete structure 5 side, as shown in Fig. 1 .

[0040] Furthermore, as shown in Figure 2, in the case of a repair member 11 in which the laminated base material 14 has a laminated structure of three or more layers, the repair member 11 may have a configuration in which a third layer 3 (described later), a first layer 1, and a second layer 2 are laminated in this order from the concrete structure 5 side.

[0041] The laminated base materials 4, 14 may each have one first layer and one second layer, or two or more layers. When two or more layers of either or both are laminated, the first layers may be laminated together and / or the second layers may be laminated together, but it is preferable that the first layers and second layers are laminated alternately. The resin fiber sheet-like member may have a two-layer structure, or only one layer may be a resin fiber sheet, or two or more layers may be resin fiber sheets, or only resin fiber sheets may be laminated.

[0042] (Sheet-shaped material made by combining multifilaments into a multiaxial mesh) As shown in Figures 1 and 2, the first layer 1 is preferably a sheet-like member in which multifilaments are combined in a multiaxial mesh shape. The multifilaments are preferably formed using long fibers and preferably have a tensile strength of 150 N or more. The value X represented by formula (1) of the sheet-like member in which multifilaments are combined in a multiaxial mesh shape is preferably 2.0 or more, more preferably 2.5 or more, 2.8 or more, or 3.0 or more.

[0043] X = A × B (1) Here, A represents the tensile strength (kN / 50 mm) of the sheet-shaped member in one direction, and B represents the number of axes of the sheet-shaped member. A can take any value by changing the number of multifilaments per 50 mm. B may range from 2 to 4. Of these, A is preferably 0.75 kN or more, and B is preferably 2 to 3.

[0044] Such a first layer 1 can fulfill the function of a load-bearing layer that receives concrete pieces that fall from the concrete structure 5.

[0045] Examples of materials for the first layer 1 include polyester, polyolefin, vinylon, aramid, carbon fiber, and glass fiber. Of these, a vinylon mesh sheet or a glass mesh sheet is preferable. The glass fiber is preferably a glass yarn or a roving. Glass yarn is a double-twisted yarn made by twisting glass fiber, and roving is a bundle of glass fibers. Examples of weaving methods for the multiaxial mesh include plain weave, twill weave, leno weave, and braided fabric. The weaving direction of the multiaxial mesh may be a biaxial or more multiaxial fabric with orthogonal directions.

[0046] The thickness of the first layer 1 is preferably 0.1 mm or more and 1.5 mm or less, and more preferably 0.3 mm or more and 1 mm or less.

[0047] The first layer is 50g / mm 2 It is preferable that the weight is 60 g / mm or more. 2 More preferably, it is 75 g / mm 2 More preferably, it is equal to or greater than this.

[0048] By setting the weight per unit area within this range, the tensile strength can be improved, and sufficient bearing capacity of the repair member can be ensured without causing breakage when concrete pieces fall off.

[0049] The first layer 1 is preferably a biaxial woven fabric with an opening size of 5 mm or more and 25 mm or less. By setting the opening size within this range, the adhesive strength between the second layer 2 and the concrete structure 5, or the adhesive strength between the second layer 2 and the third layer 3, as described below, can be improved, ensuring sufficient strength of the repair material. In addition, by setting the number of long fibers per unit area of ​​the first layer 1 to an appropriate number, the resistance of the first layer 1 when it breaks through the second layer 2 can be increased, ensuring sufficient strength of the repair material.

[0050] The first layer 1 has an opening of 5 mm or more and 25 mm or less, and is 50 g / mm 2 It is more preferable that the first layer 1 is a biaxial woven fabric having a basis weight of 150 N or more. Alternatively, it may be a multiaxial woven fabric having an opening ratio equivalent to that of the biaxial woven fabric. In particular, it is more preferable that the first layer 1 is a sheet-like member of a biaxial or triaxial mesh made by combining multifilaments having a tensile strength of 150 N or more with an opening of 5 mm to 25 mm.

[0051] (Resin fiber sheet material) 1 and 2, the second layer 2 is preferably a resin fiber sheet-like member. The second layer 2 preferably has a tear strength of 2.0 N or more. By setting the tear strength to 2.0 N or more, the second layer 2 can fulfill its function as a reinforcing layer that increases the resistance when the first layer 1 breaks through the second layer 2.

[0052] The second layer 2 may be in the form of a woven fabric or a nonwoven fabric. Examples of materials for the second layer 2 include polyester, polyolefin, vinylon, aramid, carbon fiber, and glass fiber. Among these, polypropylene nonwoven fabric or glass nonwoven fabric is preferred, and long-fiber nonwoven fabric is particularly preferred. Glass nonwoven fabric has excellent compatibility with the curable composition, allowing the curable composition to easily penetrate the fabric, and when the curable composition is cured, the repair material can be firmly fixed to the concrete structure. Suitable glass nonwoven fabrics include chopped strand mat, glass paper, and felt.

[0053] When using polypropylene nonwoven fabric, the fibers may be subjected to a hydrophilization treatment to enhance compatibility with the curable composition. The hydrophilization treatment may be carried out by any method known in the art.

[0054] The thickness of the second layer 2 is preferably 0.1 mm or more and 1.0 mm or less, and more preferably 0.15 mm or more and 0.5 mm or less. By setting the thickness within this range, the second layer 2 fulfills its function as a reinforcing layer that increases the resistance when the first layer 1 breaks through the second layer 2, and also reduces the amount of curable composition impregnated into the substrate, which is economically advantageous.

[0055] The second layer 2 is 30 g / mm 2 It is preferable that the weight is 50 g / mm or more. 2 More preferably, it is 60 g / mm or more. 2 By setting the weight within this range, the tensile strength can be improved, and sufficient yield strength of the repair material can be ensured without causing breakage when concrete pieces peel off.

[0056] The second layer 2 is preferably a biaxial woven fabric with an opening size of 3 mm to 30 mm. By setting the opening size within this range, the adhesive strength with the third layer 3 (described later) can be improved, ensuring sufficient strength of the repair material. In addition, by setting the number of long fibers per unit area of ​​the first layer 1 to an appropriate number, the resistance of the first layer 1 when it breaks through the second layer 2 can be increased, ensuring sufficient strength of the repair material.

[0057] The second layer 2 is preferably a multifilament having a tensile strength of 10 N or more, more preferably a biaxial or triaxial mesh sheet member, and is preferably a sheet member having a tear strength of 2.0 N or more.

[0058] When the laminated base material has a two-layer structure of a first layer 1 and a second layer 2, or a laminated structure of more than one layer, it is preferable that the first layer 1 is a sheet-like member in which multifilaments are combined in a multiaxial mesh pattern, and the second layer 2 is a resin fiber sheet-like member with a tear strength of 2.0 N or more, and it is preferable that the first layer 1 is a sheet-like member in which multifilaments with a tensile strength of 150 N or more are combined in a multiaxial mesh pattern with a mesh opening of 5 mm to 25 mm, and the second layer 2 is a resin fiber sheet-like member with a tear strength of 2.0 N or more.

[0059] (Third layer etc.) When the laminated base material has a three-layer or more structure, such as the laminated base material 14 shown in Fig. 2, as long as the first layer 1 is placed on the concrete structure 5 side and the second layer 2 is placed on the outside, the third and subsequent layers may be placed anywhere and in any number of layers, not limited to the configuration shown in Fig. 2. This type of laminated structure allows the repair material to have both strength and adhesion to the concrete structure.

[0060] These third and subsequent layers may be selected from the first layer 1 and second layer 2 described above, or may be any layer used in the relevant field. Considering ease of use, economy, etc., a two-layer structure or a three-layer structure is preferred. These third and subsequent layers may be selected from the first and second layers described above, or may be any layer used in the relevant field.

[0061] The third layer 3 preferably has a porosity of 90% or more and is a resin fiber sheet-like member. This ensures the impregnation of the curable composition, and therefore when the third layer 3 is placed in contact with the concrete structure 5 as shown in Fig. 2, the third layer 3 can fulfill its function as an adhesive layer that improves the adhesive strength between the repair member 11 and the concrete structure 5.

[0062] The thickness of the third layer 3 is preferably 0.1 mm or more and 1.5 mm or less, and more preferably 0.2 mm or more and 0.8 mm or less. By setting the thickness of the third layer 3 within this range, the adhesive strength between the repair members 10, 11 and the concrete structure 5 is ensured, and the amount of the hardenable composition impregnated into the laminated base materials 4, 14 can be reduced, which is economically advantageous.

[0063] (integrated lamination) The laminated substrates 4 and 14, which are formed by laminating at least two layers of sheet-like members, may be integrated by impregnating them with a curable composition, but it is preferable to integrate them in advance, which can prevent the sheet members from shifting during application and impregnation.

[0064] The integration method may utilize mechanical fiber entanglement, chemical adhesion, etc., and examples thereof include fulling, needle punching, chemical bonding, thermal bonding, and hydroentanglement.

[0065] Regardless of the configuration of the laminated substrate, the amount of the curable composition impregnated into the laminated substrate is sufficient as long as the curable composition is uniformly retained throughout the laminated substrate, and is preferably adjusted so that the entire laminated substrate can be firmly integrated by curing the curable composition. For example, the mass ratio of laminated substrate to curable composition is preferably about 1:4 to 1:12, and more preferably 1:4 to 1:10.

[0066] (Waterproof and breathable layer) The waterproof and moisture-permeable layer may be a layer formed by impregnating a waterproof and moisture-permeable material into a suitable sheet-like member, or may be a layer obtained by applying a waterproof and moisture-permeable material to a laminated substrate 4, 14 that has been coated and / or impregnated with a curable composition.

[0067] In this case, as shown in Figures 1 and 2, the waterproof and moisture-permeable layer 6 is preferably disposed on the surface of the laminated substrate 4, 14 opposite the concrete structure 5. By disposing such a waterproof and moisture-permeable layer, it is possible to improve the waterproofing while ensuring the moisture permeability of the repair members 10, 11. As a result, the repair members 10, 11 themselves can prevent concrete pieces from peeling off from deteriorated parts of the concrete structure 5 for a long period of time.

[0068] The waterproof and breathable material may be any known material containing a component that forms a silicone skeleton.

[0069] Examples of waterproof and breathable materials that form a silicone skeleton include those containing structures such as acrylic silicone and modified silicone.

[0070] Specific examples of the acrylic silicone waterproof and breathable material include Diestender 2000B Clear, a product name manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

[0071] The modified silicone-based waterproof and breathable material may be a mixture containing a modified silicone resin, an epoxy resin, a silanol condensation catalyst, and an epoxy resin curing agent as an adhesive resin composition. The modified silicone resin is not particularly limited, but is preferably a moisture-curable modified silicone resin, which in this case has a hydrolyzable silicon group. The modified silicone resin having a hydrolyzable silicon group may be a polymer of a monomer selected from the group consisting of an alkylene oxide component, an olefin component, and an acrylic component, and the polymer may be either a homopolymer or a copolymer.

[0072] The waterproof and moisture-permeable material can be used in any amount as long as it does not impair the intended function of the curable composition. For example, the amount can be appropriately set depending on the size of the laminated substrate, and the application amount can be set to 3 g / m2 or less relative to the area of ​​the laminated substrate. 2 ~1000g / m 2 The recommended thickness is 5g / m 2 ~600g / m 2From another perspective, the water absorption rate after 24 hours is preferably 75% or less, more preferably 70% or less, and even more preferably 60% or less. The water vapor transmission rate is preferably 20% or more, more preferably 30% or more, and even more preferably 50% or more.

[0073] Furthermore, it is preferable that the water absorption rate after 24 hours is 75% or less and the water vapor transmission rate is 20% or more, more preferable that the water absorption rate after 24 hours is 70% or less and the water vapor transmission rate is 30% or more, and even more preferable that the water absorption rate after 24 hours is 60% or less and the water vapor transmission rate is 50% or more. By laminating a waterproof / moisture-permeable layer having such properties to the laminate substrate, the above-mentioned effects can be further exerted.

[0074] <Methods for repairing concrete structures> The concrete structure repair method of this embodiment will be described below. Fig. 3 is a flow chart showing the concrete structure repair method.

[0075] The concrete structure repair method of the present application can be carried out using the above-mentioned concrete structure repair member. Specifically, it includes the steps of preparing a repair base member by applying or impregnating a layered substrate with a composition containing a silicate aqueous solution and a pozzolan active substance with an electrical conductivity difference of 0.4 mS / cm or more (Step S10), attaching the repair base member to the concrete structure (Step S20), hardening the attached repair base member (Step S30), and applying a waterproof / moisture-permeable material to the surface of the hardened repair base member to form a waterproof / moisture-permeable layer (Step S40).

[0076] According to such a repair method, since it is not necessary to repeatedly apply and dry a curable liquid composition such as an adhesive or binder as in the conventional method, the work can be carried out simply and efficiently, and is easy to work with.

[0077] (Preparation of foundation materials for repair) To prepare a repair base member, first, the above-described curable composition is prepared. Materials constituting the laminated substrate are also prepared. The curable composition may be applied to or impregnated into the laminated substrate after the laminated substrate is formed, or the laminated substrate may be formed by impregnating the curable composition with the curable composition after the impregnation, or the curable composition may be impregnated while the laminated substrate is being formed. The curable composition may also be applied to or impregnated into the laminated substrate either before or after the laminated substrate is attached to the target concrete structure.

[0078] Examples of methods for applying or impregnating a laminated substrate with a curable composition include (1) a hand layup method in which application is performed manually using a roller, (2) a method of applying or impregnating by spraying, (3) a method in which the thickness of the laminated substrate is defined using a mold and then the curable composition is applied to and impregnated into the laminated substrate by press-fitting, (4) a method in which the thickness of the laminated substrate is defined by reducing pressure and then the curable composition is applied to and impregnated into the laminated substrate by reduced pressure injection, (5) a method in which the laminated substrate is immersed in the curable composition, the laminated substrate is continuously impregnated with the curable composition, and then the thickness of the laminated substrate is defined by a roll, and (6) a method in which continuous application and impregnation are performed by roll transfer, etc. These methods may be used in combination.

[0079] To improve workability during impregnation and to prevent the impregnated sheets from adhering to each other and to prevent dust from adhering to the impregnated sheets, the front and back surfaces of the laminated substrate may be covered with a resin protective film, which can be removed before attaching the sheet to the concrete structure.

[0080] (Attachment process) The resulting repair base member is attached to the concrete structure. At this time, it is important to remove any air bubbles that have entered between the repair base member and the surface of the concrete structure, particularly to improve adhesion between the repair base member and the surface of the concrete structure. A suitable method for removing air bubbles is to use a roll or metal spatula to expel the air bubbles to the outside of the repair member. Figure 4 shows the repair base member 20 attached to the concrete structure 5.

[0081] (hardening process) The curing of the hardenable composition impregnated into the repair component is carried out by placing the repair base member in close contact with the concrete structure (see Figure 4). To ensure sufficient time for the hardenable composition to be impregnated into the surface of the concrete structure, the hardening time of the hardenable composition is preferably 30 to 300 minutes, more preferably 45 to 240 minutes. The hardening time can be adjusted by the amount and type of hardening catalyst in the case of organic materials, the water content in the case of inorganic materials, and, particularly in the case of geopolymers, the content of sodium, potassium, lithium, or a mixture thereof derived from the silicate aqueous solution, the ratio (SiO / MO) of SiO2 to MO (where M is sodium, potassium, or lithium) derived from the silicate aqueous solution, the difference in electrical conductivity of the pozzolanic active substance, the aluminum content, etc. Once the hardening composition is complete, the repair base member is fixed to the concrete structure, completing the repair of the concrete structure.

[0082] (Formation of waterproof and breathable layer) The waterproof and moisture-permeable layer can be formed by applying a curable composition to a laminated substrate (also referred to as a repair base member in this embodiment) impregnated with the curable composition while the laminated substrate is in close contact with the concrete structure. In particular, it is preferable to impregnate the laminated substrate with the curable composition and apply the waterproof and moisture-permeable material after the curable composition has hardened. By applying a waterproof / moisture-permeable material to the surface 20a of the laminated substrate 4 (repair base member 20) impregnated with the curable composition shown in Fig. 4, a waterproof / moisture-permeable layer 6 can be arranged in the form of a layer on the surfaces of the repair members 10, 11, as shown in Fig. 1 and Fig. 2. Note that Fig. 4 shows the laminated substrate 4 of Fig. 1, which includes the first layer 1 and the second layer 2, but the same applies to the laminated substrate 14 of Fig. 2, which includes the first layer 1, the second layer 2, and the third layer 3.

[0083] For example, from the viewpoint of the impregnation of the curable composition into the cured product or the laminated substrate, it is preferable to perform the treatment after the curing of the curable composition has progressed and the surface moisture content has fallen below 8%. From another viewpoint, it is preferable to perform the treatment within 7 days after the preparation of the curable composition, and more preferably after 30 minutes to 24 hours.

[0084] The coating method can be a common method, such as with a brush, roller, spray gun, or plasterer.

[0085] In this way, by applying a waterproof and moisture-permeable material to the surface of a repair base member in which a laminated substrate is impregnated with a curable composition, a repair member can be provided on the surface of a concrete structure.

[0086] The concrete structure repair member and repair method of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0087] Example 1 Triaxial mesh sheet made of vinylon multifilament (weight 90g / m 2 , mesh size 8 mm, thickness 0.35 mm, X=3.0) was coated with hydrophilic polypropylene spunbond nonwoven fabric (weight 30 g / m 2 A laminated substrate was prepared by laminating the sheets of paper onto a sheet of paper (0.2 mm thick, tear strength 16 N).

[0088] The triaxial mesh sheet corresponds to the "first layer" and has a basis weight of 30 g / m 2 The spunbond nonwoven fabric corresponds to the "second layer."

[0089] A silicate solution was obtained by stirring 100 g of a JIS K1408-specified No. 3 sodium silicate solution, 50 g of a 30% sodium hydroxide solution (n = 0.7), and 15 g of latex (product name: SR-151, manufactured by Nippon A&L Co., Ltd.) for 24 hours. A curable composition was prepared by mixing this with 130 g of calcined kaolin (product name: SP-33, manufactured by BASF, electrical conductivity difference: 1.1 mS / cm) that had been processed for 3 hours in a Mitsubishi Heavy Industries Ultrafine Mill (using 10 mm diameter zirconia balls, ball filling rate: 85%, and a mixture of 25% triethanolamine and 75% ethanol as a grinding aid, with 0.6% metakaolin added) at 3.3 kW / kg energy at 10°C. The viscosity of the resulting curable composition was 1000 Pa·s.

[0090] Furthermore, the content of Na2O (equivalent value) in the cured product was 11.3 wt % and the content of Al2O3 (equivalent value) was 30.9 wt % relative to the total weight of the cured product.

[0091] The sheet laminate substrate prepared above, 100 mm x 100 mm, was impregnated with 11 g of the curable composition in an environment of 23°C, and cured in an environment of 23°C. An acrylic silicone waterproof and moisture-permeable material (Dainichiseika Color & Chemicals Mfg. Co., Ltd., product name: Diestender 2000B Clear) was then evenly applied in 1 g portions three times at two-hour intervals to form a waterproof and moisture-permeable layer, thereby producing a repair member for the concrete structure of Example 1.

[0092] Example 2 The sheet laminate substrate prepared in Example 1, measuring 100 mm x 100 mm, was impregnated with 11 g of the curable composition prepared in Example 1 and cured.

[0093] A waterproof and moisture-permeable layer was formed by uniformly applying 4.5 g of a modified silicone-based waterproof and moisture-permeable material containing modified silicone resin, calcium carbonate, calcium oxide, and titanium oxide, to prepare a repair member for a concrete structure in Example 2. All of the above work was carried out in an environment of 23°C.

[0094] Comparative Example 1 A repair member for a concrete structure was produced in the same manner as in Example 1, except that the application of the acrylic silicone waterproof and moisture-permeable material was omitted.

[0095] (Water absorption rate after 24 hours of immersion) The water absorption performance of each example and comparative example was determined with reference to JIS A1404 "Testing Methods for Cement Waterproofing Agents for Construction," section 7.5, "Water Absorption Test." Specifically, the repair member prepared in each example and comparative example was attached to a 100 mm x 100 mm x 30 mm concrete surface. The side in contact with the repair member was waterproofed with aluminum tape and the terminals were sealed with silicone, specifically, Silicone JX, manufactured by Sekisui Fuller Co., Ltd. The repair member surface was partially immersed in water to a depth of 20 mm, and the water absorption after 24 hours was measured. The results are shown in Table 1. The "water absorption" value in Table 1 is the average of three measurements. The water absorption rate after 24 hours of immersion was defined as the water absorption rate of each example and comparative example divided by the water absorption rate of Comparative Example 1. In other words, the water absorption rate was determined as the ratio of the water absorption rate after 24 hours of immersion in water with and without a waterproof / breathable layer.

[0096] If the water absorption rate is 75% or less, preferably 60% or less, after 24 hours of immersion, the waterproofing performance will be equivalent to that of commercially available waterproof coatings, and sufficient waterproofing effect will be achieved against rainwater penetration.

[0097] (Water vapor permeability) The water vapor permeability of each Example and Comparative Example was evaluated with reference to JIS A1171 "Testing Methods for Polymer Cement Mortar" 7.12 "Moisture Permeability Test (Test by Moisture Absorption)." Specifically, the repair member prepared in each Example and Comparative Example was attached to a 68 mm diameter mortar, and the mortar with the repair member attached was fixed in a JIS-specified aluminum cup using epoxy adhesive so that there were no gaps. The water vapor permeability was measured based on the moisture absorption of calcium chloride sealed inside the aluminum cup. The results are shown in Table 1. The "water vapor permeability" value in Table 1 is the average of three measurements. The water vapor permeability of each Example and Comparative Example divided by the water vapor permeability of Comparative Example 1 was defined as the water vapor permeability ratio.

[0098] When the water vapor permeability is 20% or more, preferably 50% or more, it achieves moisture permeability performance equivalent to that of commercially available moisture-permeable materials for concrete, and does not hinder the evaporation of moisture from inside the concrete even when applied to the laminated base material of repair components for concrete structures.

[0099] [Table 1] The results of evaluating the water absorption rate and water vapor permeability of the repair members of each example after 24 hours of immersion confirmed that the concrete repair member of the present invention can improve the waterproofing properties of repair members for concrete structures while maintaining moisture permeability. [Industrial Applicability]

[0100] The repair member of the present invention can extend the life of a concrete structure. [Explanation of symbols]

[0101] 1 First layer 2 Second layer 3 Third layer 10, 11 Repair parts 4, 14 Laminated base material 5. Concrete structures 6. Waterproof and breathable layer 20 Repair base material

Claims

1. A repair member that is attached to the surface of a concrete structure, a hardening composition comprising an aqueous silicate solution and a pozzolan active substance having an electrical conductivity difference of 0.4 mS / cm or more; a laminated substrate, and A waterproof and moisture-permeable layer is provided on the laminated base material, The laminated base material includes a sheet-like member in which multifilaments are combined in a multiaxial mesh shape, and a resin fiber sheet member, the curable composition is contained in the laminate substrate; The waterproof and moisture-permeable layer contains a component that forms a silicone skeleton, The waterproof moisture-permeable layer is disposed on the opposite side of the laminated substrate from the concrete structure, The laminated substrate containing the cured composition does not contain a component that forms the silicone skeleton. Repair material for concrete structures.

2. 2. The repair member for a concrete structure according to claim 1, wherein the waterproof and moisture-permeable layer contains at least one component selected from the group consisting of acrylic silicone and modified silicone.

3. 3. The repair member for a concrete structure according to claim 1, wherein the waterproof and moisture-permeable layer has a water absorption rate of 75% or less and a water vapor transmission rate of 20% or more after immersion in water for 24 hours.

4. A method for repairing a concrete structure, comprising: a step of preparing a repair base member by applying or impregnating a layered substrate with a composition containing a silicate aqueous solution and a pozzolan active substance having an electrical conductivity difference of 0.4 mS / cm or more; A step of hardening the repair base member attached to the surface of the concrete structure; and applying a waterproof and moisture-permeable material to the surface of the hardened repair base member opposite the concrete structure to form a waterproof and moisture-permeable layer, The laminated base material includes a sheet-like member in which multifilaments are combined in a multiaxial mesh shape, and a resin fiber sheet member, The waterproof and breathable material forms a silicone skeleton, The repair base member does not contain a component that forms the silicone skeleton of the waterproof and breathable material. Methods for repairing concrete structures.

5. 5. The method for repairing a concrete structure according to claim 4, wherein the waterproof and moisture-permeable material contains at least one component selected from the group consisting of acrylic silicone and modified silicone.

6. The waterproof and moisture-permeable material is applied after the moisture content of the surface of the repair base member falls below 8%. The method for repairing a concrete structure according to claim 4.

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