JP6971117B2 - Kits for curable compositions, repair materials and repair methods for concrete structures - Google Patents

Description

The present disclosure relates to kits for curable compositions, repair materials and repair methods for concrete structures.

Since the main raw material of Portland cement, which has been produced in large quantities, is limestone, it emits carbon dioxide when it is calcined and decomposed into calcium oxide. Therefore, the geopolymer method is attracting attention as a technique for producing concrete without using Portland cement.
The geopolymer method is a technique for joining powders to each other by using a condensed 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, a filler containing abundant silicon and aluminum is used, and examples thereof include those called pozzolan active substances such as kaolin, clay, fly ash, silica fume, blast furnace slag, and rice husk ash. 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.

Japanese Unexamined Patent Publication No. 2008-239446 Japanese Unexamined Patent Publication No. 9-175813

When the composition described in Patent Document 1 is used, it is necessary to prolong the curing period or to cure at high temperature and high humidity in order to develop the required strength. In particular, the latter requires equipment and energy to keep the temperature and humidity high.
Further, in Patent Document 2, 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 is used. For example, it is described that it is highly reactive and cures even at room temperature. However, simply using kaolin, which is an aluminum having an oxidation coordination number of 5, cures insufficiently at room temperature and the initial strength development is insufficient. In addition, when used in an environment with a large amount of water such as an outdoor concrete structure or a tunnel where groundwater is gushed out, the water resistance after curing is not sufficient.

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

The present application includes the following inventions.
(1) A kit for a curable composition composed of 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: Aqueous composition of alkali metal silicate.
(2) The kit for a curable composition according to the above, wherein the metacaolin powder has ^{a specific surface area of 12 m 2 / g or more.}
(3) The above-mentioned kit for a curable composition, which further contains blast furnace slag powder in the first kit.
(4) The above-mentioned kit for a curable composition, which further comprises a polymer emulsion in the second kit.
(5) The kit for a curable composition according to the above, wherein the alkali metal silicate is at least one 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 including a multi-axis mesh sheet in which a tensile strength in at least one direction is 1 kN / 50 mm or more and a multifilament is 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: Aqueous 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 which exhibits initial strength by normal temperature curing and short-term curing and has excellent water adhesion resistance and combustion resistance, a repair material for a concrete structure, and a repair method. ..

(Kit for curable composition)
The kit for a curable composition of the present application is mainly a composition containing a metacaolin 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 weight by weight. % Or more composition and the aqueous composition of the silicate which is the second kit.
Since the first kit and the second kit accelerate curing for a certain period of time when mixed, it is preferable to store and transport them separately in order to maintain storage stability. By separating, storing and transporting, the first kit and the second kit can be mixed and used in an amount required at the time of construction. Further, by storing each kit without mixing, deterioration of the properties of the components constituting each kit can be suppressed, so that long-term storage stability can be maintained.

(1st kit)
The first kit is a composition containing metakaolin powder.
In addition to the metakaolin powder, the first kit may further contain blast furnace slag and / or pozzolan active material and the like.
The first kit contains aluminum having an oxygen coordination number of 5 in its composition. The 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 composition of the alkali metal silicate in the second kit, which will be described later, are used at room temperature. Sufficient reactivity can be ensured, and the adhesive strength between the repair material and the concrete structure can be increased.

The first kit, if the aluminum contained in the composition in terms Al ₂ O _3, preferably alumina content is 30 wt% or more, even more preferably more than 35 wt%. Further, when the silicon contained in the composition is _{converted into SiO 2} , the silica content is preferably 40% by weight or more, more preferably 45% by weight or more. Among them, the first kit has an alumina content of 30% by weight or more when the _{aluminum contained in the composition is converted to Al 2} O ₃ , and a silica content when the _{silicon is converted to SiO 2.} It is preferably 40% by weight or more.
In order to contain such aluminum and silicon, for example, those containing 30% by weight to 100% by weight, preferably 40% by weight to 80% by weight of metakaolin in the first kit. More preferably, it is more preferably contained in an amount of 40% by weight to 60% by weight.

Metakaolin is a substance obtained by calcining kaolin at about 500 ° C. to 900 ° C. to partially remove water of crystallization, and is an amorphous substance having pozzolan activity. The metakaolin in the first kit is a powder, and the powder is a powder or an aggregate of particles. The number average particle size (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 type particle size distribution measuring device. 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, for example, a value calculated by the BET method. The method for further activation is not limited, but methods such as pulverization classification, action of mechanical energy, and thermal spraying treatment can be used.

Any known method can be adopted as the method for pulverizing and classifying. Examples of the pulverization include a method using a jet mill, a roll mill, a ball mill and the like. Further, as the classification, a method using a sieve, a specific gravity, a wind force, a wet settling or the like can be mentioned. These means can be used together arbitrarily.
Examples of the method of applying mechanical energy include a method using a ball medium mill, a medium stirring type 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 appropriately activating. Within such a range, the crystal structure can be sufficiently modified depending on the raw material metakaolin, and the reactivity of the metakaolin powder at room temperature can be improved. In addition, the ratio of aluminum having an oxygen coordination number of 5 to the total aluminum contained in the first kit shall be 10% by weight or more by suppressing the recrystallization of minerals such as spinel and mullite in the metakaolin powder. It is possible to maintain or improve the reactivity at room temperature.
As a method of thermal spraying, 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 calcium in an amount of 20% by weight to 60% by weight in terms of calcium oxide (CaO). By including the blast furnace slag in the first kit, the curable composition can be cured more toughly. In addition, the water resistance can be improved when used in a place with a lot of water.
The blast furnace slag is preferably contained in the first kit in an amount of 0% by weight to 70% by weight, more preferably 40% by weight to 60% by weight. As the blast furnace slag, a lump or powder slag can be used as it is.
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, which will be described later, is preferably 20 parts by weight to 150 parts by weight, preferably 30 parts by weight to 100 parts by weight. Is more preferable. When the blast furnace slag powder is contained in this ratio, the water adhesion resistance of the cured product can be improved.

The pozzolan active substance is a substance that has almost no hydraulic limeness by itself, but reacts with calcium hydroxide at room temperature in the presence of water to form an insoluble compound and harden. Examples of the pozzolan active substance include clay, sediments, minerals, silica-based particles, charcoal ash, blast furnace slag and the like. Specifically, clays such as kaolin, activated clay, and acidic clay; deposits such as diatomaceous earth; minerals such as talc; silica-based particles such as silica dust, silica fumes, and aerosil; fly ash, white carbon, rice husk ash, etc. Examples include charcoal ash.

The pozzolan active substance is usually in the form of a lump or powder, but the lump or powder may be used as it is. Further, in order to activate it, those whose state has been changed by using a method such as pulverization classification, action of mechanical energy, and thermal spraying treatment may be used. As a method for pulverizing and classifying, a method for applying mechanical energy, and a method for thermal spraying, the same methods as described above can be used. 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. Fine particles with a large specific surface area have high reactivity and high adsorption capacity, so that they can exert a stabilizing effect on metals. For example, the particle size is 50 μm or less, preferably 20 μm or less, and particularly preferably 5 nm to 10 μm.

The pozzolan active substance has a silica content of 40% by weight or more based on the total mass of the pozzolan active substance when _{silicon is converted to SiO 2} , or an alumina content when _{aluminum is converted to Al 2} O _3. , 30% by mass or more with respect to the total mass of the pozzolan active substance is preferable.
The content of the pozzolan active substance in the first kit is preferably 0% by weight to 70% by weight, more preferably 40% by weight to 60% by weight.

The pozolan 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 0. Those having 8 mS / cm or more, 1.0 mS / cm or more, and 1.2 mS / cm or more are more preferable. By setting such an electric conductivity difference, it is possible to sufficiently secure the reactivity with the silicate aqueous solution. The difference in electrical conductivity is an index related to the reactivity of the pozzolan active substance induced by the alkaline substance, and the pozzolan active substance is described in "Cement Concrete Research, Vol. 19, pp. _{63-68, 1989 ”, the electric conductivity of 200 ml of Ca (OH) 2} saturated aqueous solution was measured under the condition of 40 ± 1 ° C., and then 5 g of metakaolin was added, and the mixture was stirred and the electric conductivity after 2 minutes. To measure. Then, the difference between the electric conductivity before charging and the electric conductivity after charging was calculated and used as the difference in electrical conductivity.

(2nd kit)
The second kit is a composition containing an alkali metal silicate. By mixing each of the first kit and the second kit at the time of use, the curable resin composition described below is obtained, and the reaction is started.
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.
Curing of the alkali metal silicate is carried out 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 divalent value or higher, it is possible to form a bond of Si—O—metal—O—Si and promote curing.

It is usually 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 make adjustments using JIS standard (K1408) Nos. 1 to 3 sodium silicate, No. 4 sodium silicate, and 1 and 2 types of sodium metasilicate.
The alkali metal silicates sodium silicate, potassium silicate, and lithium silicate are generally _{represented by the molecular formula of M 2} O · nSiO ₂ , meaning a composition in which n is in the range of 0.5 to 4.0 and a mixture thereof. do. n is preferably 0.7 to 3.0, more preferably 1.0 to 2.0. n can be arbitrarily adjusted by mixing the above-mentioned alkali metal silicate with an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide. As the alkali metal hydroxide, either a solid substance or an aqueous solution can be used.
The second kit is preferably, for example, an aqueous solution of 10% by weight to 60% by weight of an alkali metal silicate, an aqueous solution of 15% by weight to 50% by weight, or an aqueous solution of 20% by weight to 40% by weight, preferably 20% by weight. It is more preferably an aqueous solution of ~ 40% by weight, and even more preferably an aqueous solution of 30% by weight.

The aqueous composition of the second kit may further contain a polymer emulsion (latex). Examples of the polymer emulsion include acrylic rubber, styrene-butadiene rubber, and 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, more preferably 4% by weight to 20% by weight. Further, the polymer emulsion is preferably contained in an amount of 2% by weight to 10% by weight as a solid content weight with respect to the total weight of the dry solid content of the curable composition obtained by mixing the first kit and the second kit. This makes it possible to improve the adhesive strength of the cured product of the curable composition and suppress the drying shrinkage of the cured product.

(Curable composition)
The curable composition contains a reactant obtained by reacting the first kit with the second kit. In addition to this reaction product, the curable composition may contain components constituting the first kit and the second kit, respectively. The ratio between the first kit and the second kit in this case varies depending on, for example, the concentration of the aqueous solution of the alkali metal silicate contained in the second kit, and is, for example, 70 to 20:30 to 80 by weight. It is preferably 65-25: 35-75, and more preferably 65-25: 35-75. In this case, the second kit is preferably, for example, an aqueous solution of 10% by weight to 60% by weight of an alkali metal silicate, an aqueous solution of 15% by weight to 50% by weight, or an aqueous solution of 20% by weight to 40% by weight. A 20% by weight to 40% by weight aqueous solution is more preferable, and a 30% by weight aqueous solution is further preferable.
By mixing and reacting the first kit and the second kit, the curable composition can be rapidly cured at room temperature. The cured product obtained by curing the curable composition can improve the water adhesion resistance and can develop / maintain high strength at the initial stage and over a long period of time. And, this initial strength development can be realized by normal temperature curing and short-term curing. Further, by using such a curable composition, it is possible to provide a repair material for preventing peeling of a concrete structure having excellent combustion resistance.
The reason is that since the 5-coordinated metacaolin is contained in the first kit in an amount of 10% by weight or more, the reactivity between the first kit and the second kit is increased.

(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. In addition, the second kit may contain a surfactant or the like. These additives may be added to the curable composition obtained by mixing the first kit and the second kit. Known curing agents, fillers, modifiers, curing retarders, surfactants and the like can be used.

A curing accelerator is a substance that promotes curing. The curing accelerator is a component for accelerating the curing of sodium silicate, potassium silicate, lithium silicate or a mixture thereof. As described above, the curing accelerator is preferably adjusted to around neutral pH in order to promote the dehydration reaction. Also, in order to form a Si-O-metal-O-Si bond and promote curing, the alkali metal in sodium silicate, potassium silicate, lithium silicate or a mixture thereof may be replaced with a metal having a divalent value or higher. What can be done is preferable. 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. It is more preferable to use one or more compounds selected from the group consisting of organic acid esters, metal oxides and metal hydroxides.

The organic acid ester has an advantage that the formation of Si—O bond can be promoted by generating an acid in an aqueous solution. Examples of the organic acid ester include carbonic acid ester and acetic acid ester. Of these, triacetin is preferable.
Examples of the dialdehyde include malondialdehyde and the like.
Examples of the inorganic acid ester include esters such as nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid, for example, trimethyl phosphate and the like.
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 hydrogencarbonate.
Examples of the inorganic acid metal salt include alkali metals such as nitrate, hydrochloric acid, sulfuric acid and phosphoric acid, and alkaline earth metal salts such as magnesium sulfate.
Metal oxides and metal hydroxides can form Si—O-metal-O-Si bonds by leaching metal ions and cure sodium silicate, potassium silicate, lithium silicate or mixtures thereof. .. Examples of the metal oxide and the metal hydroxide include magnesium hydroxide, magnesium carbonate, calcium carbonate, calcium hydroxide and the like.

As the curing accelerator, magnesium hydroxide and magnesium carbonate are preferable from the viewpoint of preventing the curing agent from settling in the curable composition and the viewpoint of easily impregnating the glass fiber.

The filler is a substance that increases the solid content in the liquid by being added to the curable composition and makes the cured product dense. Examples of the filler include an organic filler (for example, cellulose and the like) and an inorganic filler (for example, carbon, mineral fine powder, synthesized inorganic crystal powder, calcium carbonate and the like) 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 the cured product obtained by curing the curable composition to improve the surface strength. Examples of the modifier include various metal salts capable of reacting with an aqueous silicate solution, and examples thereof include light-baked magnesium oxide and zinc oxide.

Examples of the curing retarder include sucrose, sodium tartrate, citric acid, metal chelating agents and the like.
The surfactant is a substance that contributes to the dispersion stabilization of the curable composition. The surfactant may be anionic, cationic or nonionic. Of these, nonionic surfactants are preferable. 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, polyoxyentylene alkyl ether, octaethylene glycol monododecyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, and lauric acid diethanolamide. And so on.

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 in an amount of 10% by weight or less based on the total weight of the curable composition.

[Repair material]
The repair material for the concrete structure of the present invention includes the above-mentioned curable composition and a mesh sheet. The mesh sheet may be a single layer, but is preferably a laminated body containing at least one layer of mesh sheets.

(Mesh sheet or laminate)
The mesh sheet is preferably a multi-axis mesh sheet in which at least one layer is a combination of multifilaments. The multifilament is preferably composed of long fibers. Further, when it is combined with another mesh sheet to form a laminated body, it does not necessarily have to be a multi-axis 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. Of these, it is preferably made of a vinylon mesh sheet or a glass mesh sheet. As the glass fiber, it is preferable to use glass yarn or roving. The glass yarn is made by twisting glass fibers into a twisted yarn, and the roving is a bundle of glass fibers. Examples of the weaving method of the multi-axis mesh include plain weave, twill weave, entwined weave, and braided cloth. Further, the weaving direction of the multi-axis mesh may be an orthogonal biaxial or more multi-axis woven fabric.

The thickness of the mesh sheet is preferably 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 a mesh spacing of 5 mm 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 basis weight within such a 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 of 1 kN / 50 mm or more in at least one direction, and more preferably a multi-axis combination of multifilaments having a tensile strength of 1 kN / 50 mm or more in at least one direction. It is more preferable that the biaxial or triaxial mesh sheet is a combination of the above, having a tensile strength of 1 kN / 50 mm or more in at least one direction and a mesh spacing of 5 mm to 25 mm. Further, 1000 kN / 50 mm or less, 500 kN / 50 mm or less, and 300 kN / 50 mm are preferable.
The value X represented by the formula (1) of the laminated body in which multifilaments are combined in a multiaxial mesh shape is preferably 2.0 or more, and 2.5 or more, 2.8 or more, or 3.0 or more. Is more preferable.
X = A × B (1)
Here, A represents the tensile strength kN / 50 mm in one direction of the mesh sheet or the sheet-shaped member, and B represents the number of axes of the mesh sheet or the sheet-shaped member. A can be set to an arbitrary value by changing the number of multifilaments per 50 mm. B includes 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 or more.
With such a configuration, the mesh sheet can satisfy the function as a load-bearing layer for receiving 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 fabrics and non-woven fabrics. Examples of the material include polyester, polyolefin, vinylon, aramid, carbon fiber, glass fiber and the like. Among them, it is preferably composed of polypropylene non-woven fabric or glass non-woven fabric, and more preferably long fiber non-woven fabric. Since the glass nonwoven fabric has excellent compatibility with the curable composition, the curable composition easily permeates, and the repair material can be firmly fixed to the concrete structure when the curable composition is cured. Suitable glass non-woven fabrics include chopped strand mats, glass paper, felt and the like.
When a polypropylene non-woven fabric is used, it is preferable to surface-treat the fiber surface in order to enhance the compatibility with the curable composition.
The total thickness of the mesh sheet or laminate is preferably 0.1 mm to 1.0 mm, more preferably 0.15 mm to 0.5 mm. By setting the thickness in such a range, the mesh sheet can function as a reinforcing layer and the content of the curable composition can be suppressed, which is economically advantageous.

When the mesh sheet is used as a laminated body, the laminated body may be integrated in advance. By integrating in advance, it is possible to prevent the sheets from being displaced when the curable composition is contained in the laminate including the mesh sheet.
As the method of integration, mechanical fiber entanglement, chemical adhesion and the like can be used, and examples thereof include fluffing, needle punching, chemical bond, thermal bond, water flow entanglement and the like.
The laminated body may have, for example, a two-layer structure, a three-layer structure, four layers or more, and the number of layers is not particularly limited.

As a method for incorporating the curable composition into the mesh sheet or laminate, various methods such as coating, spraying, dipping, press-fitting, vacuum injection and the like are used for incorporating the curable composition into the mesh sheet or laminate. It can be mentioned that it is included. In order to improve workability at this time, and to prevent dust from adhering to the repair material and the repair materials from adhering to each other, the front and back surfaces of the mesh sheet or laminate after containing the curable composition are covered with a resin protective film. You may cover it. This protective film is removed when it is attached to a concrete structure.

The curable composition may be contained in the mesh sheet at the site before being attached to the concrete structure, or may be attached to the concrete structure and impregnated at the same time. The curable composition is contained in the base material by applying the curable composition to the surface of the concrete structure and pasting the above-mentioned base material (sheet-like member or laminate) on the curable composition. It may be carried out by applying the curable composition or the like 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 retained throughout the mesh sheet or the laminate, and the curable composition is cured by the curing of the mesh sheet or the laminate. It is preferable to adjust so that the entire laminate can be firmly integrated. For example, the weight ratio of the mesh sheet or the laminate: the curable composition is preferably about 1: 4 to 1:20, more preferably 1: 4 to 1:15.

[Repair method]
The concrete can be repaired by attaching the repair material obtained by containing the curable composition in the above-mentioned mesh sheet or laminate to the 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, at the time of pasting, it is preferable to press appropriately. It is also preferable to remove air bubbles that have entered between the repair material and the surface of the concrete structure. This makes it possible to improve the adhesion between the repair material and the surface of the concrete structure. As a method for removing bubbles, it is preferable to use a roller, a spatula, or the like to expel the bubbles to the outside of the repair material.

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

Curing of the curable composition contained in the mesh sheet or the laminate can be performed by maintaining the state in which the repair material is in close contact with the concrete structure. For example, the curing time of the composition may be 10 minutes to 180 minutes, and may be 20 minutes to 120 minutes. The curing time can be adjusted by adjusting 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 of the present invention and the repair material for the concrete structure 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 having an oxygen coordination number of 5 of 10% by weight or more and a specific surface area of 12 m ^{2 / g or more with respect to the total aluminum in the composition contained in the first kit.}
, Creating C,
Metakaolin powders D, E, having an oxygen coordination number of 5 of aluminum in an abundance of 10% by weight or more and a specific surface area of 12 m ^{2 / g or less with respect to the total aluminum in the composition contained in the first kit.} Creation of F,
The metakaolin powders G and H having an oxygen coordination number of 5 of less than 10% by weight and a specific surface area of 12 m ^{2 / g or more with respect to the total aluminum in the composition contained in the first kit.} It was created by the following method.
Metakaolin powders I and J having an oxygen coordination number of less than 10% by weight and a specific surface area of ^{less than 12 m 2 / g with respect to the total aluminum in the composition contained in the first kit.} It was created by the following method.

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

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

(Preparation of metakaolin powders G and H)
The metakaolin powder G was prepared in the same manner as the metakaolin powder A except that the treatment was performed with an energy of 50 kWh / kg.
Further, the metakaolin powder H was prepared in the same manner as the metakaolin powder A except that the treatment was performed with an energy of 70 kWh / kg.

(Preparation of Metakaolin Powder I)
Metakaolin powder I was prepared in the same manner as metakaolin powder A except that the metakaolin powder was made of ASHAPURA MINECHEM LIMITED: METAX RX.

(Preparation of Metakaolin Powder J)
Metakaolin powder J was prepared in the same manner as Metakaolin powder I except that it was not crushed.

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

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

In addition, a mesh sheet made of vinylon multifilament with a mesh spacing of 10 mm (thickness: 1 mm, grain amount: 100 g / m ² , tensile strength 150 kN / 50 mm) and a glass non-woven fabric (grain size 25 g / m ² , thickness 0.2 mm). 3 layers of sheet-like members were laminated by laminating one sheet on the concrete-attached surface side and one polypropylene non-woven fabric (grain size 30 g / m ^{2, thickness 0.2 mm) on the outermost surface layer on the opposite side.} A fiber sheet laminate was produced.
A repair material for a concrete structure was prepared by impregnating the prepared sheet laminate 300 mm × 300 mm with 100 g of a curable composition.
This was attached to a concrete flat plate (JIS A 5371) having a thickness of 300 mm × 300 mm × 60 mm, and allowed to stand in a room at 23 ° C. and 50% RH for 3 days to be cured to obtain an evaluation sample.

Examples 4-7
The metakaolin powders A, D, E and F and the blast furnace slag powder were mixed at the ratios shown in Table 3 to obtain the first kit.
The second kit was obtained by mixing the components shown in Table 3 in each ratio.
Then, a curable composition was obtained in the same manner as in Example 1 and the like.
Further, an evaluation sample was obtained in the same manner as in Example 1 and the like.

Comparative Examples 1-5
The metakaolin powders G, H, I, J and the blast furnace slag powder were mixed at the ratios shown in Tables 4 and 5 to obtain the first kit.
A second kit was obtained in the same manner as in Example 1, a curable composition, a fiber sheet laminate, and a repair material for a concrete structure were prepared, and an evaluation sample was obtained in the same manner as in Example 1.

<Adhesion evaluation>
・ Before soaking in water (initial)
A 40 mm × 40 mm steel adherent was attached to the obtained Examples and Comparative Examples with a two-component epoxy adhesive (trade name: Bond E-250, manufactured by Konishi Co., Ltd.), and a weight having a mass of 1 kg was placed on the sample. The product was allowed to stand for 24 hours in a 50% RH atmosphere at 23 ° C. and cured. Then, a concrete cutter was used to make a cut around the steel adhering material until it reached a flat plate. An adhesion strength test based on JSCE-E545 was performed using a simple single-screw tensile tester (TechnoStar R-10000ND).
10 days after soaking in water The samples obtained in Examples and Comparative Examples were allowed to stand for 10 days with the whole sample completely immersed in water at 23 ° C, and then the sample was taken out from the water and 50% RH at 23 ° C. It was allowed to stand for 16 hours in an atmosphere. After that, the steel adherent was attached, hardened, and notched by the same method as in the initial stage, and the adhesion strength test was performed.

<Combustion resistance evaluation>
NEXCO test method The test method was performed based on the test method 738-2011 "Fire spread test method for tunnel repair material".
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 excellent. 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 Al content of the coordination number 5 in the first kit is less than 10% by weight, the adhesive force after 10 days of immersion in water is low. confirmed.

Claims (7)

A kit for a curable composition composed of 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: Aqueous composition of alkali metal silicate. The kit for a curable composition according to claim 1, wherein the metakaolin powder has ^{a specific surface area of 12 m 2 / g or more.} The kit for a curable composition according to any one of claims 1 to 2, wherein the first kit further contains blast furnace slag powder. The kit for a curable composition according to any one of claims 1 to 3, further comprising a polymer emulsion in the second kit. The kit for a curable composition 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 reactant of the first kit and the second kit,
A repair material for a concrete structure including a multi-axis mesh sheet in which a tensile strength in at least one direction is 1 kN / 50 mm or more and a multifilament is 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: Aqueous composition of alkali metal silicate. A repair method for repairing using the repair material according to claim 6.