JP2019006661A - Curable composition kit, and concrete structure repair material and repair method - Google Patents

Abstract

To provide a curable composition kit that exhibits initial strength by room temperature hardening and short period cure and excellent in water-proof adhesion force and flammability resistance, and provide a concrete structure repair material and repair method.SOLUTION: A curable composition kit comprises a first kit and a second kit. The first kit is a composition containing metakaolin powder, where the composition has 10 weight% or more of an aluminum percentage with the oxygen coordination number of 5 to aluminum included in the composition, and the second kit is an aqueous solution composition of alkaline metal silicate.SELECTED DRAWING: None

Description

  The present disclosure relates to a curable composition kit, a repair material for a concrete structure, and a repair method.

Portland cement, which has been produced in large quantities in the past, emits carbon dioxide when calcined and decomposed into calcium oxide because its main raw material is limestone. For this reason, the geopolymer method has attracted attention as a technique for producing concrete that does not use Portland cement.
The geopolymer method is a technique for joining powders using a condensation polymer of silicic acid as a binder. As a geopolymer composition used in this geopolymer method, a composition composed of a filler, an alkaline solution and an aggregate has been proposed (for example, Patent Document 1). As the filler, those containing abundant silicon and aluminum are used, and examples thereof include those called pozzolanic active substances such as kaolin, clay, fly ash, silica fume, blast furnace slag, rice husk ash and the like. As the alkaline solution, an aqueous solution of sodium hydroxide or potassium hydroxide and water glass (Na ₂ SiO ₃ ) or potassium silicate (K ₂ SiO ₃ ) is generally used.

JP 2008-239446 A JP-A-9-17581

When the composition described in Patent Document 1 is used, the curing period is prolonged or curing at high temperature and high humidity is required in order to develop the necessary strength. In particular, the latter requires equipment and energy to maintain high temperature and high humidity.
Patent Document 2 uses kaolin in which at least a part of aluminum contained in kaolin obtained by applying mechanical energy of 0.5 kWh / kg to 30 kWh / kg is aluminum having an oxygen coordination number of 5. For example, it is described that it is highly reactive and can be cured at room temperature. However, simply using kaolin, which is aluminum having an oxidation coordination number of 5, is insufficient in curing at room temperature and insufficient in initial strength. In addition, when used in an environment with a lot of water such as outdoor concrete structures and tunnels where groundwater springs out, the water resistance after curing is not sufficient.

  In view of the above problems, the present invention provides a curable composition kit that exhibits initial strength by room temperature curing and short-term curing, and has excellent water adhesion and combustion resistance, a repair material for a concrete structure, and a repair method. For the purpose.

The present application includes the following inventions.
(1) A curable composition kit comprising a first kit and a second kit.
First kit: A composition comprising metakaolin powder, wherein the ratio of aluminum having an oxygen coordination number of 5 to the total aluminum contained in the composition is 10% by weight or more,
Second kit: An aqueous solution composition of alkali metal silicate.
(2) The kit for a curable composition as described above, wherein the metakaolin powder has a specific surface area of 12 m ² / g or more.
(3) The kit for curable composition as described above, wherein the first kit further contains blast furnace slag powder.
(4) The kit for curable composition as described above, wherein the second kit further contains a polymer emulsion.
(5) The kit for curable composition as described above, wherein the alkali metal silicate is one or more selected from the group consisting of sodium silicate, potassium silicate, and lithium silicate.
(6) a curable composition containing a reaction product of the first kit and the second kit;
A repair material for a concrete structure having a tensile strength in at least one direction of 1 kN / 50 mm or more and a multiaxial mesh sheet in which multifilaments are combined.
First kit: A composition containing metakaolin powder, wherein the ratio of aluminum having an oxygen coordination number of 5 to the total aluminum contained in the composition is 10% by weight or more.
Second kit: An aqueous solution composition of alkali metal silicate.
(7) A repair method for repairing using the repair material described above.

  According to the present invention, it is possible to provide a kit for a curable composition that exhibits initial strength at room temperature curing and short-term curing, and is excellent in water adhesion and combustion resistance, a repair material for a concrete structure, and a repair method. .

(Curable composition kit)
The kit for a curable composition of the present application is mainly a composition containing metakaolin powder, which is the first kit, and the ratio of aluminum having an oxygen coordination number of 5 to aluminum contained in the composition is 10% by weight. % Composition and an aqueous solution composition of silicate which is the second kit.
When the first kit and the second kit are mixed, curing is promoted for a certain period of time. Therefore, in order to maintain storage stability, it is preferable to store and transport them separately. By separating and storing and transporting, the first kit and the second kit can be mixed and used in an amount necessary for construction. Moreover, since each kit can be stored without being mixed, deterioration of the properties of the components constituting each kit can be suppressed, so that long-term storage stability can be maintained.

(First kit)
The first kit is a composition containing metakaolin powder.
The first kit may further contain a blast furnace slag and / or a pozzolanic active substance in addition to the metakaolin powder.
The first kit includes aluminum with an oxygen coordination number of 5 in the composition. Aluminum having an oxygen coordination number of 5 is 10% by weight or more, preferably 20% by weight or more, based on the total aluminum contained in the composition. Since aluminum having an oxygen coordination number of 5 is highly reactive, the metakaolin powder and / or blast furnace slag in the first kit and the aqueous solution composition of the alkali metal silicate in the second kit described below at room temperature. Sufficient reactivity can be secured, and the adhesive strength between the repair material and the concrete structure can be increased.

In the first kit, when the aluminum contained in the composition is converted to Al ₂ O ₃ , the alumina content is preferably 30% by weight or more, and more preferably 35% by weight or more. Further, when silicon contained in the composition is converted to SiO ₂ , the silica content is preferably 40% by weight or more, and more preferably 45% by weight or more. In particular, the first kit has an alumina content of 30% by weight or more when aluminum contained in the composition is converted to Al ₂ O ₃ , and a silica content when silicon is converted to SiO _2. What is 40 weight% or more is preferable.
In order to contain such aluminum and silicon, for example, the first kit preferably contains 30% by weight to 100% by weight of metakaolin, and 40% by weight to 80% by weight. More preferably, 40 to 60% by weight is more preferable.

Metakaolin is obtained by baking kaolin at about 500 ° C. to 900 ° C. to remove part of water of crystallization, and is amorphous and has pozzolanic activity. The metakaolin in the first kit is a powder, and the powder is an aggregate of powder or particles. The number average particle diameter (D50) of the metakaolin powder is 0.1 μm to 20 μm, preferably 0.5 μm to 15 μm. The powder can be measured with a laser diffraction / scattering particle size distribution measuring apparatus. The metakaolin powder preferably has a specific surface area of 12 m ² / g or more in order to be more activated. The specific surface area of the powder means a value calculated by the BET method, for example. The method for more activation is not limited, but methods such as pulverization classification, action of mechanical energy, and thermal spraying can be used.

Any known method can be adopted as a method for pulverization and classification. Examples of the pulverization include a method using a jet mill, a roll mill, a ball mill and the like. In addition, classification includes a method using a sieve, specific gravity, wind force, wet sedimentation and the like. These means can be arbitrarily used together.
Examples of the method for applying mechanical energy include a method using a ball medium mill, a medium stirring mill, a roller mill, and the like. The mechanical energy to be applied is preferably 0.5 kwh / kg to 30 kwh / kg in order to minimize the load while being appropriately activated. By setting it as such a range, modification | denaturation of crystal structure becomes enough depending on the raw material metakaolin, and the reactivity of the metakaolin powder at room temperature can be improved. In addition, suppressing the recrystallization of minerals such as spinel and mullite in the metakaolin powder, the ratio of aluminum having an oxygen coordination number of 5 to the total aluminum contained in the first kit should be 10% by weight or more. And the reactivity at room temperature can be maintained or improved.
As a thermal spraying method, a thermal spraying technique applied to a ceramic coating is applied. Examples of the thermal spraying technique include a plasma spraying method, a high energy gas spraying method, and an arc spraying method. Preferably, the material powder is melted at a temperature of 2000 ℃ ~16000 ℃, it is preferable to spray at a speed of 30 m / sec ～800M / sec, a specific surface area of the powder of 12m ² / g~100m ² / g.

Blast furnace slag is produced when pig iron is produced in a blast furnace, has pozzolanic activity, and contains CaO, SiO ₂ , Al ₂ O ₃ , and MgO as main components. Examples of the blast furnace slag include those containing 20 to 60% by weight of calcium in terms of calcium oxide (CaO). When the first kit contains blast furnace slag, the curable composition can be hardened more strongly. Moreover, when using it in a place with much water, water resistance can be improved.
In the first kit, the blast furnace slag is preferably contained in an amount of 0 to 70% by weight, more preferably 40 to 60% by weight. In addition, the blast furnace slag can be used in the form of a lump or powder.
The content of the blast furnace slag in the first kit composition with respect to 100 parts by weight of the aqueous solution composition of the second kit described later is preferably 20 parts by weight to 150 parts by weight, and 30 parts by weight to 100 parts by weight. Is more preferable. When blast furnace slag powder is contained in this proportion, the water-resistant adhesion of the cured product can be improved.

  A pozzolanic active substance is a substance that has almost no hydraulic property per se, but reacts with calcium hydroxide at room temperature in the presence of water to form an insoluble compound and harden. Examples of the pozzolanic active material include clay, deposits, minerals, silica-based particles, coal ash, and blast furnace slag. Specifically, clays such as kaolin, activated clay and acid clay; sediments such as diatomaceous earth; minerals such as talc; silica-based particles such as silica dust, silica fume and aerosil; fly ash, white carbon, rice husk ash and the like Examples include charcoal ash.

The pozzolanic active substance is usually a lump or powder, but a lump or powder may be used as it is. Moreover, in order to activate, you may use what changed the state using methods, such as a grinding | pulverization classification, the effect | action of mechanical energy, and a thermal spraying process. The method similar to the above can be utilized for the method of pulverizing and classifying, the method of applying mechanical energy, and the method of spraying. Among them, that the material powder is melted at a temperature of 2000 ℃ ~16000 ℃, sprayed at a rate of 30 m / sec ～800M / sec, a specific surface area of the powder of 0.1m ² / g~100m ² / g preferable. A fine one having a large specific surface area has a high reactivity and a high adsorbing ability, so that it can exert a stabilizing effect on the metal. For example, the particle diameter is 50 μm or less, preferably 20 μm or less, particularly preferably 5 nm to 10 μm.

The pozzolanic active material has a silica content of 40% by weight or more based on the total mass of the pozzolanic active material when silicon is converted to SiO ₂ , or an alumina content when aluminum is converted to Al ₂ O _3. It is preferable that it is 30% by weight or more based on the total mass of the pozzolanic active substance.
The content of the pozzolanic active substance in the first kit is preferably 0% by weight to 70% by weight, and more preferably 40% by weight to 60% by weight.

The pozzolanic active substance preferably has an electric conductivity difference of 0.4 mS / cm or more, more preferably 0.5 mS / cm or more, 0.6 mS / cm or more, or 0.7 mS / cm or more, and More preferable are 8 mS / cm or more, 1.0 mS / cm or more, or 1.2 mS / cm or more. By setting it as such an electrical conductivity difference, the reactivity with silicate aqueous solution is fully securable. The difference in electrical conductivity is an index related to the reactivity of a pozzolanic active substance induced by an alkaline substance. For the pozzolanic active substance, “Cement Concrete Research, Vol. 19, pp. 63-68, 1989 ”, the electrical conductivity of 200 ml of a saturated aqueous solution of Ca (OH) ₂ was measured under the condition of 40 ± 1 ° C., and then 5 g of metakaolin was added and stirred for 2 minutes. Measure. Then, the difference between the electric conductivity before charging and the electric conductivity after charging was calculated and used as the electric conductivity difference.

(Second kit)
The second kit is a composition containing an alkali metal silicate. By mixing the first kit and the second kit at the time of use, the curable resin composition described below is obtained, and the reaction starts.
Examples of the alkali metal silicate include one or more selected from the group consisting of sodium silicate, potassium silicate, and lithium silicate. Of these, sodium silicate is preferable from the viewpoint of price and availability.
The alkali metal silicate is cured by inducing a dehydration reaction and forming a Si—O bond when mixed with the first kit. Further, by replacing the alkali metal of the alkali metal silicate with a metal having a valence of 2 or more, it is possible to form a Si—O—metal—O—Si bond to accelerate the curing.

In general, it is preferable to use an alkali metal silicate in the form of an aqueous solution because of its ease of handling. For example, commercially available sodium silicate, potassium silicate, lithium silicate, or a mixture thereof can be used. In particular, it is easy to adjust using JIS standard (K1408) Nos. 1 to 3 silicate, No. 4 silicate, sodium metasilicate 1 type, and 2 types.
The alkali metal silicates sodium silicate, potassium silicate, and lithium silicate are generally expressed by a molecular formula of M ₂ O · nSiO ₂ , and n means a composition in a range of 0.5 to 4.0 and a mixture thereof. To do. n is preferably 0.7 to 3.0, and more preferably 1.0 to 2.0. n can be arbitrarily adjusted by mixing the alkali metal silicate described above and an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, lithium hydroxide and the like. As the alkali metal hydroxide, either a solid or an aqueous solution can be used.
The second kit is preferably an aqueous solution of 10 wt% to 60 wt% alkali metal silicate, an aqueous solution of 15 wt% to 50 wt%, or an aqueous solution of 20 wt% to 40 wt%, for example, 20 wt% It is more preferably an aqueous solution of ˜40% by weight, and further preferably an aqueous solution of 30% by weight.

  The aqueous solution composition of the second kit may further contain a polymer emulsion (latex). Examples of the polymer emulsion include acrylic rubber, styrene butadiene rubber, or a mixture thereof. Of these, styrene butadiene rubber is preferable. The content of the polymer emulsion in the second kit is preferably 0% by weight to 50% by weight, and more preferably 4% by weight to 20% by weight. Moreover, it is preferable that 2 to 10 weight% of solid emulsion weights are contained with respect to the total weight of the dry solid content of the curable composition which mixed the 1st kit and the 2nd kit. Thereby, the adhesive strength of the hardened | cured material of a curable composition can be improved, and the drying shrinkage of hardened | cured material can be suppressed.

(Curable composition)
The curable composition includes a reaction product obtained by reacting the first kit and the second kit. In addition, the curable composition may contain the component which each comprises a 1st kit and a 2nd kit other than this reaction material. In this case, the ratio between the first kit and the second kit varies depending on, for example, the concentration of the aqueous solution of alkali metal silicate contained in the second kit, but is, for example, 70 to 20:30 to 80 by weight. It is preferable that it is 65-25: 35-75. The second kit in this case is preferably, for example, an aqueous solution of 10 wt% to 60 wt% alkali metal silicate, an aqueous solution of 15 wt% to 50 wt%, or an aqueous solution of 20 wt% to 40 wt%, It is more preferably a 20% to 40% by weight aqueous solution, and even more preferably a 30% by weight aqueous solution.
By mixing and reacting the first kit and the second kit, the curable composition can be rapidly cured at room temperature. A cured product obtained by curing the curable composition can improve water adhesion and develop / maintain high strength over an initial period and a long period of time. And this initial intensity | strength expression is realizable by normal temperature hardening and short-term curing. Furthermore, by using such a curable composition, it is possible to provide a repair material for preventing a concrete structure from peeling off, which has excellent combustion resistance.
The reason is that the reactivity between the first kit and the second kit is increased because the first kit contains 10% by weight or more of 5-coordinate metakaolin.

(Other ingredients)
The curable composition of the present invention may contain additives known in the art in addition to the above components. For example, the first kit may contain a curing accelerator, a filler, a modifier, and a curing retarder. The second kit may contain a surfactant and the like. These additives may be added to the curable composition obtained by mixing the first kit and the second kit. Known curing accelerators, fillers, modifiers, curing retarders, surfactants, and the like can be used.

  A curing accelerator is a substance that accelerates curing. A hardening accelerator is a component for accelerating hardening of sodium silicate, potassium silicate, lithium silicate, or a mixture thereof. As described above, the curing accelerator is preferably adjusted to near pH neutrality in order to promote the dehydration reaction. In addition, in order to form a Si-O-metal-O-Si bond to promote curing, the alkali metal in sodium silicate, potassium silicate, lithium silicate, or a mixture thereof may be replaced with a divalent or higher metal. What can be done is preferred. The curing accelerator preferably contains at least one selected from the group consisting of organic acid esters, dialdehydes, inorganic acid esters, organic acid metal salts, inorganic acid metal salts, metal oxides and metal hydroxides. More preferably, at least one compound selected from the group consisting of organic acid esters, metal oxides and metal hydroxides is used.

Organic acid esters have the advantage that the formation of Si—O bonds can be promoted by generating an acid in an aqueous solution. Examples of the organic acid ester include carbonate ester and acetate ester. Of these, triacetin is preferable.
Examples of the dialdehyde include malondialdehyde.
Examples of inorganic acid esters include esters such as nitric acid, hydrochloric acid, sulfuric acid, and phosphoric acid, such as trimethyl phosphate.
Examples of the organic acid metal salt include alkali metals such as formic acid, acetic acid, malonic acid, and carbonic acid, and alkaline earth metal salts such as sodium hydrogen carbonate.
Examples of the inorganic acid metal salt include alkali metals such as nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid, and alkaline earth metal salts such as magnesium sulfate.
A metal oxide and a metal hydroxide can form a Si-O-metal-O-Si bond by dissolving a metal ion, and can cure sodium silicate, potassium silicate, lithium silicate, or a mixture thereof. . Examples of the metal oxide and metal hydroxide include magnesium hydroxide, magnesium carbonate, calcium carbonate, and calcium hydroxide.

  As the curing accelerator, magnesium hydroxide and magnesium carbonate are preferable from the viewpoint of preventing sedimentation of the curing agent in the curable composition and easy impregnation of the glass fiber.

The filler is a substance that increases the solid content in the liquid by being added to the curable composition and densifies the cured product. Examples of the filler include organic fillers (for example, cellulose) and inorganic fillers (for example, carbon, mineral fine powder, synthesized inorganic crystal powder, calcium carbonate, and the like). Examples of the mineral fine powder include hard sandstone powder, silica sand powder, zeolite, zirconia, and silica powder.
The modifier is a substance that modifies and densifies the surface of a cured product obtained by curing the curable composition, thereby improving the surface strength. Examples of the modifier include various metal salts capable of reacting with an aqueous silicate solution, such as light-burned magnesium oxide and zinc white.

Examples of the retarder include sucrose, sodium tartrate, citric acid, and metal chelating agents.
The surfactant is a substance that contributes to stabilizing the dispersion of the curable composition. The surfactant may be any of anionic, cationic and nonionic. Of these, nonionic surfactants are preferred. Examples of the anionic surfactant include sodium lauryl sulfate, sodium lauryl sulfate, sodium linear alkylbenzene sulfonate and the like. Examples of the cationic surfactant include tetramethylammonium chloride, tetramethylammonium hydroxide, and monomethylamine hydrochloride. Nonionic surfactants include sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, octaethylene glycol monododecyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene glycol, lauric acid diethanolamide Etc.

  These additives can be used in any content as long as the intended action of the curable composition is not impaired. Usually, it is preferably blended at 10% by weight or less with respect to the total weight of the curable composition.

[Repair materials]
The repair material for a concrete structure of the present invention includes the curable composition described above and a mesh sheet. The mesh sheet may be a single layer, but is preferably a laminate including at least one layer of mesh sheet.

(Mesh sheet or laminate)
The mesh sheet is preferably a multiaxial mesh sheet in which at least one layer is a combination of multifilaments. The multifilament is preferably constructed using long fibers. Furthermore, when it is combined with other mesh sheets to form a laminated body, it is not always necessary to use a multiaxial mesh sheet in which multifilaments are combined.
Examples of the mesh sheet include those formed of polyester, polyolefin, vinylon, aramid, carbon fiber, glass fiber, and the like. Especially, it is preferable to consist of a vinylon mesh sheet or a glass mesh sheet. The glass fiber is preferably a glass yarn or roving. The glass yarn is obtained by twisting glass fibers to form a twisted yarn, and the roving is obtained by focusing glass fibers. Examples of the method of weaving the multiaxial mesh include plain weave, twill weave, entangled weave, and braided fabric. Further, the direction of weaving of the multiaxial mesh may be a biaxial orthogonal or more multiaxial woven fabric.

The mesh sheet preferably has a thickness of 0.1 mm to 5 mm, more preferably 0.3 mm to 3 mm. The mesh sheet is preferably a biaxial woven fabric or a multiaxial woven fabric combined in a mesh shape with an interval of 5 to 25 mm.
The mesh sheet preferably has a basis weight of 50 g / m ² or more, more preferably 60 g / m ² or more, and further preferably 75 g / m ² or more. By setting the weight per unit area within this range, the tensile strength can be improved, and sufficient proof stress of the repair material can be ensured without causing breakage when the concrete piece is peeled off.

The mesh sheet preferably has a tensile strength in at least one direction of 1 kN / 50 mm or more, more preferably a multiaxial combination of multifilaments and a tensile strength in at least one direction of 1 kN / 50 mm or more. It is more preferable that the biaxial or triaxial mesh sheet is a combination of multiaxial, biaxial or triaxial mesh sheets having a tensile strength in at least one direction of 1 kN / 50 mm or more and an interval of 5 to 25 mm. Moreover, 1000 kN / 50 mm or less, 500 kN / 50 mm or less, and 300 kN / 50 mm are preferable.
In addition, it is preferable that the value X represented by Formula (1) of the laminated body which combined the multifilament in the shape of a multiaxial mesh is 2.0 or more, 2.5 or more, 2.8 or more, or 3.0 or more. It is more preferable that
X = A × B (1)
Here, A represents the tensile strength kN / 50 mm in one direction of the mesh sheet or sheet-like member, and B represents the number of axes of the mesh sheet or sheet-like member. A can take an arbitrary value by changing the number of multifilaments per 50 mm. Examples of B include those having a range of 2 to 4. Among them, A is preferably 1 kN / 50 mm or more, more preferably 50 kN / 50 mm or more, further preferably 150 kN / 50 mm or more, and B is preferably 2 to 3.
With such a configuration, the mesh sheet can satisfy the function as a load-bearing layer that receives the concrete pieces falling from the concrete structure.

The repair material preferably includes, for example, a sheet-like member in addition to the mesh sheet. Examples of the sheet-like member include woven fabric and non-woven fabric. Examples of the material include polyester, polyolefin, vinylon, aramid, carbon fiber, and glass fiber. Especially, it is preferable that it is comprised with a polypropylene nonwoven fabric or a glass nonwoven fabric, and it is especially more preferable that it is a long fiber nonwoven fabric. Since the glass nonwoven fabric is excellent in compatibility with the curable composition, the curable composition easily penetrates, and the repair material can be firmly fixed to the concrete structure when the curable composition is cured. Suitable glass nonwoven fabrics include chopped strand mats, glass paper, felts and the like.
In the case of using a polypropylene nonwoven fabric, it is preferable to perform a surface treatment on the fiber surface in order to enhance compatibility with the curable composition.
The total thickness of the mesh sheet or laminate is preferably 0.1 mm to 1.0 mm, and more preferably 0.15 mm to 0.5 mm. By setting it as the range of such thickness, while being able to fulfill | perform the function as a reinforcement layer of a mesh sheet | seat, content of a curable composition can be suppressed and it is economically advantageous.

When the mesh sheet is used as a laminate, the laminate may be integrated in advance. By integrating in advance, displacement of each sheet when the curable composition is contained in a laminate including a mesh sheet can be prevented.
The integration method can utilize mechanical fiber entanglement, chemical bonding, etc., and examples thereof include crimping, needle punching, chemical bonding, thermal bonding, hydroentangling, and the like.
The stacked body may have, for example, a two-layer structure, a three-layer structure, four layers or more, and the number of stacked layers is not particularly limited.

  The method of incorporating the curable composition into the mesh sheet or laminate uses various methods such as coating, spraying, dipping, press-fitting, and vacuum injection, for example, by incorporating the curable composition into the mesh sheet or laminate. Can be included. In order to increase the workability at this time, and to prevent the adhesion of dust to the repair material and the adhesion of the repair materials, the front and back surfaces of the mesh sheet or laminate after containing the curable composition are covered with a resin protective film. It may be covered. This protective film is removed when it is applied to a concrete structure.

  As the timing of inclusion of the curable composition in the mesh sheet, it may be contained in the field before application to the concrete structure, or application to the concrete structure and impregnation may be performed simultaneously. Further, the inclusion of the curable composition into the base material is performed by applying the curable composition to the surface of the concrete structure and attaching the above-described base material (sheet-like member or laminate) thereon. Alternatively, it may be carried out by applying the curable composition while bringing the above-mentioned base material into contact with the concrete structure, or these may be carried out once or more.

  The content of the curable composition in the mesh sheet or the laminate is not particularly limited, and the curable composition is uniformly held throughout the mesh sheet or the laminate, and the mesh sheet or the laminate is cured by the curing of the curable composition. It is preferable to adjust so that the whole laminated body can be firmly integrated. For example, the weight ratio of mesh sheet or laminate: curable composition is preferably about 1: 4 to 1:20, and more preferably 1: 4 to 1:15.

[Repair method]
Repair of concrete can be performed by sticking a repair material obtained by adding a curable composition to the mesh sheet or laminate described above to a concrete structure and curing the curable composition.
As a method of attaching the repair material to the concrete structure, a known method can be used. For example, when pasting, it is preferable to press moderately. It is also preferable to remove air bubbles that have entered between the repair material and the surface of the concrete structure. Thereby, the adhesiveness of repair material and the surface of a concrete structure can be improved. As a method for removing bubbles, it is preferable to expel bubbles to the outside of the repair material using a roller, a spatula, or the like.

Further, the method for simultaneously applying the repair material to the concrete structure and containing the curable composition in the mesh sheet or the laminate is not particularly limited. For example, A) Mesh sheet to the concrete structure Alternatively, the laminate is temporarily fixed with an adhesive tape or the like, and the curable composition is applied from the surface using a roller, spatula, trowel, brush, or the like. B) The cured composition is applied to the surface of the concrete structure with a roller or spatula. , Applying with a trowel, brush, etc., and laminating a mesh sheet or laminate on it, and squeezing it with a roller, spatula, etc. C) After the method B, further from above the mesh sheet or laminate Examples thereof include a method of coating the cured composition with a roller, a spatula, a trowel, a brush, and the like.

Curing of the curable composition contained in the mesh sheet or the laminate can be performed by maintaining the state of the repair material in close contact with the concrete structure. For example, the curing time of the composition is 10 minutes to 180 minutes, and can be 20 minutes to 120 minutes. The curing time can be adjusted by the composition ratio of the composition, the ambient temperature, and the like. When the curing of the composition is completed, the repair material is firmly fixed to the concrete structure, and the repair of the concrete structure is completed. The repair material may be heated for curing but may be maintained at ambient temperature.
Hereinafter, the curable resin composition and the repair material for a concrete structure of the present invention will be described in more detail with reference to examples. The present invention is not limited to these.

(Preparation of metakaolin powder)
Metakaolin powders A and B in which the proportion of aluminum having an oxygen coordination number of 5 is 10% by weight or more and the specific surface area is 12 m ² / g or more with respect to the total aluminum in the composition contained in the first kit.
, Creation of C,
Metakaolin powders D, E, in which the proportion of aluminum having an oxygen coordination number of 5 is 10% by weight or more and the specific surface area is 12 m ² / g or less based on the total aluminum in the composition contained in the first kit; Creation of F,
Of metakaolin powders G and H in which the proportion of aluminum having an oxygen coordination number of 5 is less than 10% by weight and the specific surface area is 12 m ² / g or more based on the total aluminum in the composition contained in the first kit. Creation was performed by the following method.
Of the metakaolin powders I and J, the proportion of aluminum having an oxygen coordination number of 5 is less than 10% by weight and the specific surface area is less than 12 m ² / g with respect to the total aluminum in the composition contained in the first kit. Creation was performed by the following method.

(Production of metakaolin powders A and B)
2 kg of metakaolin powder (Imeris, Polestar450) and 10 g of a mixture of 25% triethanolamine and 75% ethanol as a grinding aid, Ultra Fine Mill AT-20 (manufactured by Mitsubishi Heavy Industries, Ltd., 10 mmφ zirconia ball filling rate 85 %) Was processed with an energy of 20 kWh / kg to prepare metakaolin powder A.
Then, the same treatment was performed except that the energy was 30 kWh / kg, and metakaolin powder B was prepared.
(Preparation of metakaolin powder C)
A metakaolin powder C was prepared in the same manner as the metakaolin powder A except that the metakaolin powder was made by BASF: SP-33.

(Preparation of metakaolin powder D)
A metakaolin powder D was prepared in the same manner as the metakaolin powder A except that the pulverization treatment was not performed.
(Production of metakaolin powder E)
Metakaolin powder E was prepared in the same manner as metakaolin powder A, except that it was treated with an energy of 1.5 kWh / kg.
(Preparation of metakaolin powder F)
A metakaolin powder F was prepared in the same manner as the metakaolin powder C except that the pulverization treatment was not performed.

(Production of metakaolin powders G and H)
Metakaolin powder G was prepared in the same manner as metakaolin powder A, except that it was treated with an energy of 50 kWh / kg.
Further, a metakaolin powder H was prepared in the same manner as the metakaolin powder A except that it was treated with an energy of 70 kWh / kg.

(Production of metakaolin powder I)
A metakaolin powder I was prepared in the same manner as the metakaolin powder A except that the metakaolin powder was changed to METAX RX manufactured by ASHAPURA MINECHEM LIMITED (Ashapura).

(Creation of metakaolin powder J)
A metakaolin powder J was prepared in the same manner as the metakaolin powder I except that it was not crushed.

(Measurement of the abundance ratio of aluminum having an oxygen coordination number of 5)
The measurement of the oxygen coordination number spectrum of aluminum in each metakaolin powder was measured by ²⁷ Al MAS NMR. The sample was filled in a solid 4 mm probe rotor, and measurement was performed by the DD / MAS method at a sample rotation speed of 15 kHz and a waiting time of 2 seconds. Peaks having oxygen coordination numbers of 4, 5, and 6 appeared in the spectrum. The proportion of aluminum having an oxygen coordination number of 5 was fitted by a Lorentz function and calculated by an area ratio (area of oxygen coordination number 5 with respect to the total area of oxygen coordination numbers 4, 5, and 6).
(Measurement of specific surface area)
The specific surface area of each metakaolin powder was determined by the BET method by measuring the amount of nitrogen adsorbed at each relative pressure with a nitrogen adsorption amount measuring device (manufactured by Kanta Cream: autosorb-1).
The results are shown in Table 1.

Examples 1-3
A composition containing metakaolin powders A, B, and C in the proportions shown in Table 2 was prepared to obtain a first kit.
Further, an aqueous sodium silicate solution adjusted to a solid content of 27% by weight and SiO ₂ / Na ₂ O (molar ratio) = 1.6, latex (trade name: LX407 F43, manufactured by Nippon Zeon Co., Ltd.), styrene butadiene rubber (solid content 50 %)) For 24 hours at the ratio shown in Table 2 to prepare an aqueous solution composition to obtain a second kit. Thereby, the kit for curable compositions was comprised.
Then, the 1st kit and the 2nd kit were mixed in the ratio shown in Table 2, and the curable composition was prepared.

Further, a mesh sheet (thickness: 1 mm, weight per unit area: 100 g / m ² , tensile strength 150 kN / 50 mm) made of vinylon multifilament and a glass nonwoven fabric (weight per unit area 25 g / m ² , thickness 0.2 mm) Was laminated on the concrete sticking surface side, and a polypropylene non-woven fabric (weight per unit area 30 g / m ² , thickness 0.2 mm) was laminated on the outermost surface layer on the opposite side, thereby laminating three sheet-like members. A fiber sheet laminate was prepared.
A repair material for a concrete structure was prepared by impregnating the prepared sheet laminate 300 mm × 300 mm with 100 g of the curable composition.
This was bonded to a 300 mm × 300 mm × 60 mm thick concrete flat plate (JIS A 5371), allowed to stand in a room at 23 ° C. and 50% RH for 3 days, and cured to obtain an evaluation sample.

Examples 4-7
Metakaolin powders A, D, E, F and blast furnace slag powder were mixed in the proportions shown in Table 3 to obtain a first kit.
Moreover, the 2nd kit was obtained by mixing the component shown in Table 3 in each ratio.
Then, the curable composition was obtained like Example 1 grade | etc.,.
Moreover, the evaluation sample was obtained like Example 1 grade | etc.,.

Comparative Examples 1-5
Metakaolin powder G, H, I, J and blast furnace slag powder were mixed in the ratios shown in Tables 4 and 5 to obtain a first kit.
A second kit was obtained in the same manner as in Example 1, repair materials for curable compositions, fiber sheet laminates, and concrete structures were prepared, and evaluation samples were obtained in the same manner as in Example 1.

<Adhesion evaluation>
・ Before water immersion (initial)
A 40 mm × 40 mm steel adhesive is attached to the obtained samples of Examples and Comparative Examples with a two-part epoxy adhesive (trade name: Bond E-250, manufactured by Konishi Co., Ltd.), and a weight of 1 kg is put on the sample. It was allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH to be cured. Then, it cut | incised until it reached the flat plate around the steel adhesion piece with the concrete cutter. The adhesion strength test based on JSCE-E545 was performed using a simple uniaxial tensile tester (Technostar R-10000ND).
-10 days after water immersion The samples obtained in the examples and comparative examples were allowed to stand for 10 days in a state where the entire sample was completely immersed in water at 23 ° C, and then the sample was taken out of water and 23 ° C and 50% RH. It was allowed to stand for 16 hours under an atmosphere. After that, the steel adhesion piece was attached, cured, and cut by the same method as the initial stage, and an adhesion strength test was conducted.

<Flame resistance evaluation>
NEXCO Test Method Test method 738-2011 “Test method for fire spreadability of tunnel repair material” was performed.
These results are shown in Tables 2-5.

From the results of Tables 2 and 3, as shown in Examples 1 to 7, by using the components of the second kit in combination with the components of the first kit, the initial strength is excellent even at room temperature, and the water resistance is high. It was confirmed that a repair material having excellent combustion resistance can be obtained.
On the other hand, from the results of Tables 4 and 5, in Comparative Examples 1 to 5, since the content of Al having a coordination number of 5 in the first kit is less than 10% by weight, the adhesion strength after 10 days of water immersion is low. confirmed.

Claims (7)

A curable composition kit comprising a first kit and a second kit.
First kit: A composition containing metakaolin powder, wherein the ratio of aluminum having an oxygen coordination number of 5 to the total aluminum contained in the composition is 10% by weight or more.
Second kit: An aqueous solution composition of alkali metal silicate. The curable composition kit according to claim 1, wherein the metakaolin powder has a specific surface area of 12 m ² / g or more.   The kit for curable compositions according to any one of claims 1 to 2, further comprising blast furnace slag powder in the first kit.   The curable composition kit according to any one of claims 1 to 3, wherein the second kit further contains a polymer emulsion.   The curable composition kit according to any one of claims 1 to 4, wherein the alkali metal silicate is one or more selected from the group consisting of sodium silicate, potassium silicate, and lithium silicate. A curable composition comprising a reaction product of the first kit and the second kit;
A repair material for a concrete structure having a tensile strength in at least one direction of 1 kN / 50 mm or more and a multiaxial mesh sheet in which multifilaments are combined.
First kit: A composition containing metakaolin powder, wherein the ratio of aluminum having an oxygen coordination number of 5 to the total aluminum contained in the composition is 10% by weight or more.
Second kit: An aqueous solution composition of alkali metal silicate.   The repair method repaired using the repair material of Claim 6.