JP2008002176A - Composite and production method thereof - Google Patents

Abstract

An object of the present invention is to provide a composite capable of suppressing neutralization, salt damage, and the like by applying an organic-inorganic composite-type coating agent after spraying to a sprayable material that can be thickened. .
A spraying material containing cement, a fine powder of pozzolana, a holmite-based mineral and / or a polymer thickener, an aggregate, a fluidizing agent and / or an air entraining agent, and a setting accelerator. It is the composite_body | complex which coats the organic-inorganic composite type coating agent on the surface of this. In the composite, the aggregate includes sand and a lightweight aggregate, and further includes at least one selected from an expansion material, a shrinkage reducing agent, and a fiber. The organic-inorganic composite-type coating agent contains a synthetic resin aqueous dispersion, a water-soluble resin, and a swellable clay mineral, and the swellable clay mineral is a synthetic fluoromica, The amount used is preferably 50 to 500 g / m ² . Moreover, it is the manufacturing method of the said composite_body | complex which coats the organic-inorganic composite-type coating agent on the surface of a spraying material.
[Selection figure] None

Description

  The present invention relates to a composite that suppresses neutralization, salt damage, and the like by applying an organic-inorganic composite coating agent to a spray material for repairing and reinforcing concrete structures, particularly in the civil engineering and construction fields.

  When the concrete structure deteriorates due to salt damage, neutralization, freezing and thawing, chemical corrosion, or the like, the surface is cracked or floated. In addition, even when subjected to fatigue or fire damage due to repeated loading, concrete pieces are peeled off due to cracks or explosions. As countermeasures, a construction is performed in which a deteriorated portion is confirmed by a hammering inspection or the like, removed by an electric pick, an air pick, a water jet, or the like, and newly repaired with a repair member. In such repair work, the spraying method is often applied when the repair sectional area is wide. The construction method by spraying is generally a method in which mortar that has been kneaded is pumped with a pump, mixed with compressed air, and blown off the mortar. The system is mechanized, so the construction speed is fast and repairs are performed. There is an advantage that it is excellent in adhesion to the cross section and can be densely filled on the back side of the reinforcing bar.

In the spraying method, a polymer cement mortar containing a polymer emulsion specified in JIS A 6203 is often used. By mixing the polymer emulsion, it is possible to impart the effects of improving durability, improving adhesion, and reducing dust and rebound, but the polymer emulsion is an expensive material. Moreover, the spraying thickness per layer of the spray material mixed with the polymer emulsion is less than 50 mm when sprayed on the ceiling surface, and if the thickness is further increased, sagging or peeling may occur.
Therefore, there is also known a technology that can reduce dripping and rebound as a spraying material without using a polymer emulsion, and by using a holmite-based mineral or a montmorillonite-based mineral without using a quick setting agent (Patent Document) 1 and 2).
Furthermore, in the case of the conventional construction method, the coating thickness per time is about 20 to 40 mm on the wall surface and about 10 to 20 mm on the ceiling surface, and it is necessary to apply a multilayer coating. Reference 3) has been developed.

On the other hand, the sprayed material after construction reacts with calcium hydroxide when carbon dioxide in the air penetrates into the interior and lowers the pH, and when this reaches the rebar position, the alkalinity decreases, so the passive film on the rebar surface Is destroyed and rust is generated. The expansion force at that time causes cracking and floating of the spray material, and further deterioration causes the spray material to peel off. Such a deterioration phenomenon is neutralization. In addition, even when chloride ions permeate, the passive film of the reinforcing bar is destroyed and rust is generated, and the spray material is cracked and floated.
Usually, the spray material used for repair members is excellent in neutralization suppression effect and chloride ion penetration resistance, but it may deteriorate after a long time after construction, so construction can be performed easily. Thus, there has been a demand for a coating material and a construction method that can maintain long-term effects against neutralization and salt damage.

It is described that when an organic-inorganic composite type film curing agent is applied, no dimensional change occurs in the curing and curing process (see Patent Document 3). In addition, a method of applying an organic-inorganic composite coating film to a hardened cement body and curing it has also been proposed (see Patent Document 5).
However, Patent Document 4 discloses nothing about applying an organic-inorganic composite coating agent to the surface of mortar or concrete, and shows an effect of suppressing the permeability of carbon dioxide gas or chloride ions. Not. Patent Document 5 shows that when applied to a hardened cement body, it suppresses the dissipation of moisture and reduces the change in length, but it shows the effect of suppressing the permeability of carbon dioxide and chloride ions. It has not been.

Japanese Patent Laid-Open No. 06-264449 Japanese Patent Laid-Open No. 08-217514 JP 2002-201058 A JP 2002-274976 A JP 2005-162534 A

  The present invention provides a composite capable of suppressing neutralization, salt damage, and the like by applying an organic-inorganic composite coating film after spraying to a sprayable material that can be thickened. To do.

That is, the present invention includes (1) cement, pozzolanic fine powder, holmite mineral and / or polymer thickener, aggregate, fluidizing agent and / or air entraining agent, and setting accelerator. A composite characterized by coating an organic-inorganic composite coating film on the surface of the containing spray material, (2) the aggregate is a spray material containing sand and lightweight aggregate (1) (3) A composite according to (1) or (2), which is a spray material containing at least one selected from an expansion material, a shrinkage reducing agent, and a fiber, and (4) organic- The composite according to any one of (1) to (3), wherein the inorganic composite-type coating agent contains a synthetic resin aqueous dispersion, a water-soluble resin, and a swellable clay mineral, (5) an organic-inorganic composite-type coating film (1)-(4) the composite according to any one of (1) to (4), wherein the swelling clay mineral of the agent is synthetic fluorine mica, Machine - The amount of the inorganic composite coating agent, conjugate of any of a ^{50~500g / m 2 (1) ~} (5), the organic to the surface (7) spraying material - inorganic composite type coating (1) It is a manufacturing method of the composite_body | complex in any one of (1) which coats a film agent.

  In the present invention, a composite that suppresses neutralization, salt damage, and the like can be obtained by applying an organic-inorganic composite coating agent after spraying to a sprayable material that can be thickened.

Hereinafter, the present invention will be described in detail.
Unless otherwise specified, parts and% in the present invention are shown on a mass basis.

  The cement used in the present invention is not particularly limited, but various portland cements defined in JIS R 5210, various mixed cements defined in JIS R 5211, JIS R 5212, and JIS R 5213, Examples thereof include one or more selected from blast furnace cement, fly ash cement, silica cement, filler cement mixed with limestone powder, alumina cement and the like, which are manufactured at the admixture mixing rate specified in JIS or more.

The pozzolanic fine powder used in the present invention is intended to impart thixotropic properties and improve the compactness of the hardened structure.For example, blast furnace granulated slag, blast furnace slag, slag such as converter slag, silica fume, Examples include fly ash and other natural pozzolanic active substances represented by volcanic ash. Furthermore, considering the improvement effect of chloride ion penetration resistance, it is preferable to use blast furnace granulated slag, blast furnace slow-cooled slag, and a mixture thereof.
The particle size of the pozzolanic fine powder is not particularly limited, but is preferably 3000 cm ² / g or more.
The amount of pozzolanic fine powder used is preferably 3 to 20 parts, more preferably 5 to 15 parts, per 100 parts of cement. If it is less than 3 parts, there is little provision of thixotropic property, and if it exceeds 20 parts, the thixotropic property is too high and it may affect the securing of fluidity.

The holmite mineral used in the present invention is a fibrous inorganic mineral that imparts thixotropy. For example, hydrated magnesium aluminum silicate attapulgite, palygorskite, hydrous magnesium silicate sepiolite and the like can be mentioned. Among them, the use of attapulgite is preferable because it is difficult to inhibit fluidity.
The average length of the holmite-based mineral is preferably 1 to 3 microns from the viewpoint of giving appropriate thixotropy. Further, it is preferable from the viewpoint of safety to use a holmite mineral having a crystalline silica content of 1% or less.
The amount of holmite mineral used is preferably 0.02 to 5 parts and more preferably 0.06 to 3 parts with respect to 100 parts of cement. If it is less than 0.02 part, thixotropy is not imparted, and if it exceeds 5 parts, fluidity may be affected.

The polymer thickener used in the present invention is for adjusting the viscosity of the mortar and is not particularly limited, but is generally called a water-soluble polymer substance. , Polyvinyl alcohol, polyacrylic acid and its sodium and potassium salts, polyethylene oxide, etc., used to prevent the mortar from bouncing off and falling off, and to improve the sliding of the mortar during pumping Is done.
Of these, hydroxyethyl methylcellulose is preferred. Hydroxyethyl methylcellulose has a hydroxyethoxy group content of 4 to 20%. This powder is mixed with hot water so as to form a 2% aqueous solution, dispersed, cooled with stirring, and has a light transmittance at 30 ° C. The thing of 45% or more is preferable. This cellulose derivative is characterized by excellent solubility in alkali in a wide temperature range from low temperature to high temperature, so there is no variation in viscosity imparting effect, and when used in combination with holmite minerals, it is stable and hardly affected by temperature. Thixotropy can be obtained. It is also called other water-soluble polymer substances, and methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, polyacrylic acid or its sodium salt or potassium salt, and polyethylene oxide may be used in combination. Is possible.
The usage-amount of a polymeric thickener is 0.02-0.5 part normally with respect to 100 parts of cement, and 0.05-0.3 part is more preferable. If it is less than 0.02 part, the effect of reducing the rebound of the mortar is small, and if it exceeds 0.5 part, the improvement of the effect may not be expected.

The aggregate used in the present invention is not particularly limited, but natural aggregate (sand) usually produced from rivers, mountains, and seas with a bulk density exceeding 0.7 g / m ³ , and these Two or more kinds of mixed aggregates and the like. Furthermore, a lightweight aggregate etc. can be used together.
The aggregate may be mixed at the construction site, but when it is mixed with cement in advance, a dry aggregate obtained by drying the aggregate may be used.
The amount of aggregate used is preferably 50 to 260 parts with respect to 100 parts of cement. If it is less than 50 parts, dripping may increase when sprayed, and if it exceeds 260 parts, rebound may increase.

The lightweight aggregate used in the present invention has a bulk density of 0.7 g / cm ³ or less, and is used for the purpose of reducing the mortar density in order to prevent sagging immediately after spraying.
There are no particular restrictions on the type of lightweight aggregate, but recycling of fly ash balloons generated from thermal power plants, shirasu shirasu balloons, foams fired from natural materials such as obsidian, waste glass, etc. Examples include those fired using materials as raw materials, and those having a bulk density of 0.7 g / cm ³ or less can be used.
The amount of the lightweight aggregate is preferably 2 to 15 parts, more preferably 4 to 10 parts with respect to 100 parts of sand. If it is less than 2 parts, the mortar density cannot be sufficiently reduced, and if it exceeds 15 parts, fluidity may be affected.

The fluidizing agent used in the present invention is not particularly limited, and examples thereof include melamine-based, naphthalene-based, lignin-based, and polycarboxylic acid-based agents, and are used for adjusting the fluidity of mortar.
The amount of the fluidizing agent used is preferably 0.02 to 0.5 part and more preferably 0.06 to 0.3 part with respect to 100 parts of cement. If the amount is less than 0.02 part, the effect of improving the fluidity may be small. If the amount exceeds 1 part, the fluidity may be too good and dripping or rebounding may increase.
Although the mixing method of the fluidizing agent of the present invention is not particularly limited, for example, it is preferable that the fluidizing agent is previously dispersed in cement or in cement or water.

The air-entraining agent used in the present invention is used for the purpose of reducing the pressure resistance by lightening the kneaded mortar or further improving the freeze-thaw resistance by the effect of the entrained entrained air.
The type of air entraining agent is not particularly limited, and commercially available products can be used. For example, fatty acid soaps such as Vinsol, higher alcohol sulfate esters such as polyoxyethylene alkyl sulfate, ethers such as polyoxyethylene alkyl ether and polyoxyalkyl phenyl ether, ester ethers such as polyoxyethylene sorbitan oleate, Examples include betaines and imidazoline betaines.
The amount of the air entraining agent used is preferably 0.0005 to 0.05 part, more preferably 0.001 to 0.02 part with respect to 100 parts of cement. If it is less than 0.0005 parts, the air mixing effect is small, and if it exceeds 0.05 parts, air mixing may increase excessively.

The setting accelerator used in the present invention accelerates the setting of the mortar, and promotes the setting to such an extent that it does not hinder kneading and feeding the mortar.
Examples of the setting accelerator include lithium, sodium, potassium carbonate, bicarbonate, sulfate, silicate, hydroxide, formate, acetate, and the like. Of these, the use of lithium, sodium and potassium silicates and formates is preferred because they do not adversely affect mortar mixing and pumping.
Use in combination with a set retarder if it can be improved by using a set retarder such as an organic acid or phosphate even if it adversely affects kneading and pumping of the mortar by adding a set accelerator. Also good.
0.1-1 part is preferable with respect to 100 parts of cement, and, as for the usage-amount of a setting accelerator, 0.2-0.8 part is more preferable. If the amount is less than 0.1 part, the effect of promoting the setting cannot be sufficiently exhibited. If the amount exceeds 1.0 part, the mortar may be mixed and pumped adversely.

  The organic-inorganic composite-type coating agent used in the present invention contains a synthetic resin aqueous dispersion, a water-soluble resin, and a swellable clay mineral, and further contains these and a crosslinking agent. Is.

The synthetic resin aqueous dispersion referred to in the present invention is generally a synthetic resin emulsion, an aromatic vinyl monomer, an aliphatic conjugated diene monomer, an ethylenically unsaturated fatty acid monomer, and other It can be obtained by emulsion polymerization of one or more of the copolymerizable monomers. For example, styrene / butadiene latex mainly composed of styrene, styrene / acrylic emulsion, methyl methacrylate / butadiene latex copolymerized with styrene, and ethylene / acrylic emulsion. The synthetic resin emulsion is more preferably one having a carboxyl group or a hydroxy group.
Here, the emulsion polymerization is a general emulsion polymerization method in which a monomer to be polymerized is mixed, and an emulsifier, a polymerization initiator, etc. are added to the monomer and the reaction is carried out in an aqueous system.
In order to obtain blending stability with the swellable clay mineral, it is preferable to use a basic substance such as ammonia, amines and caustic soda and adjust the pH to 5 or more.
The particle size of the synthetic resin aqueous dispersion is generally 100 to 300 nm, but preferably has a small particle size of about 60 to 100 nm.

Examples of water-soluble resins include modified starch or derivatives thereof, cellulose derivatives, saponified polyvinyl acetate or derivatives thereof, polymers having sulfonic acid groups or salts thereof, polymers or copolymers of acrylic acid or salts thereof, Examples include acrylamide polymers and copolymers, polyethylene glycol, and oxazoline group-containing polymers, and one or more of them can be used.
The water-soluble resin may be one having a solubility in pure water of 1% or more at normal temperature, and preferably 10 to 60% of hydrogen bonding groups or ionic groups per unit weight of the resin. The average molecular weight is preferably 2,000 to 1,000,000.
The amount of the water-soluble resin used is preferably 0.05 to 200 parts in terms of solid content with respect to 100 parts of solid content of the synthetic resin aqueous dispersion. If the amount is less than 0.05 parts, the moisture resistance may be lowered. If the amount exceeds 200 parts, the moisture resistance may be significantly lowered.

Examples of swellable clay minerals include layered silicate minerals belonging to the scumite genus. For example, montmorillonite, beidellite, nontronite, saponite, synthetic fluorine mica, bentonite and the like. Any of natural products, synthetic products, and processed products can be used. Of these, synthetic fluorine mica is preferable. Among them, a clay mineral having a swelling power of 20 ml / 2 g or more by a method according to the Japan Bentonite Industry Association, standard test method JBAS-104-77 is preferable. Further, the ion exchange equivalent is preferably 10 milliequivalents or more, more preferably 60 to 200 milliequivalents or more per 100 g. Furthermore, the thing whose aspect ratio is 50-5000 is preferable. The aspect ratio is the length / thickness ratio of the clay mineral dispersed in layers obtained by electron micrograph.
The amount of the swellable clay mineral is preferably 1 to 50 parts with respect to 100 parts of the solid content of the synthetic resin aqueous dispersion. If it is less than 1 part, the moisture-proof property may be reduced and blocking may occur easily, and if it exceeds 50 parts, the film deformability of the coating agent may be reduced.

A cross-linking agent reacts with a hydrophilic functional group such as a carboxyl group, an amide group, and a hydroxyl group contained in an aqueous dispersion of a water-soluble resin or synthetic resin to crosslink, polymerize (three-dimensional network structure), or hydrophobize. Those having an oxazoline group that undergoes an addition reaction with a carboxyl group are also preferable because they also serve as water-soluble resins.
The amount of the crosslinking agent used is preferably 0.01 to 30 parts in terms of solid content with respect to 100 parts of the total solid content of the synthetic resin aqueous dispersion and the water-soluble resin. If the amount is less than 0.01 part, the moisture resistance may be lowered. If the amount exceeds 30 parts, the moisture resistance and the anti-blocking property reach a peak.

In the present invention, an organic-inorganic composite coating agent is prepared by mixing a synthetic resin aqueous dispersion, a water-soluble resin, and a swellable clay mineral, and further reacting these with a crosslinking agent.
The organic-inorganic composite coating agent is preferably synthesized by mixing the water-soluble resin and the swellable clay mineral in water in advance and then mixing the synthetic resin aqueous dispersion and the crosslinking agent.
The organic-inorganic composite coating agent is a polymer dispersion dispersed in water, and the amount of solid content to be contained is not particularly limited. The solid content concentration affects the strength and thickness of the film formed when applied to mortar or concrete, ease of application, and the like.
10-60% is preferable and, as for the solid content density | concentration of the coating agent when apply | coating to a spraying material, 20-50% is more preferable. If it is less than 10%, the effect of suppressing neutralization is not sufficient, and if it exceeds 60%, it becomes difficult to apply because the viscosity becomes high, and improvement of the effect cannot be expected.
The organic (inorganic) composite coating agent coating (coating) method is not particularly limited as long as it can form a uniform coating film, and can be distributed, applied, or sprayed. Is possible. The coating time of the organic-inorganic composite coating agent on the spray material is not particularly limited, but is preferably after the spray material is cured.
As an example of the organic-inorganic coating agent, “CA2” series manufactured by Toagosei Co., Ltd. can be used.
The organic-inorganic composite coating agent is preferably used in an amount of 50 to 500 g, more preferably 100 to 400 g, per 1 m ² . If it is less than 50g, the effect which suppresses neutralization is not enough, and even if it exceeds 500g, the improvement of the further effect cannot be anticipated.

The expansion material used in the present invention is used to reduce the curing shrinkage due to drying of the mortar, and is not particularly limited, but those such as Auin, calcium aluminoferrite, and lime are used. Can be mentioned.
The amount of the expansion material used is usually preferably 1 to 10 parts, more preferably 2 to 8 parts, relative to 100 parts of cement. If it is less than 1.0 part, the effect which suppresses hardening shrinkage is not enough, and even if it mixes exceeding 10 parts, the improvement of the effect is few.

  The shrinkage reducing agent used in the present invention is not particularly limited, but is preferably a polyoxyalkylene derivative, the general formula of which is represented by X {O (AO) nR} m, and X is 2-8. A residue of a compound having a hydroxyl group, AO is an oxyalkylene group having 2 to 18 carbon atoms, R is a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an acyl group having 2 to 18 carbon atoms, n is 30 to 30 1000 and m are 2 to 8, and 60 mol% or more of the oxyalkylene group is composed of a polyoxyalkylene derivative which is an oxyethylene group. When the value of n is less than 30, the melting point becomes low and it becomes difficult to use it in powder form. When the value of n exceeds 1000, the viscosity becomes high and the production becomes difficult. When the oxyethylene group is less than 60 mol%, the melting point is lowered and the solubility in the cement solution is lowered.

In the general formula X {O (AO) nR} m, X is a residue of a compound having 2 to 8 hydroxyl groups. Examples of the compound having 2 to 8 hydroxyl groups include ethylene glycol, propylene glycol, butylene glycol. , Hexylene glycol, styrene glycol, alkylene glycols having 8 to 18 carbon atoms, glycols such as neopentyl glycol, glycerin, diglycerin, polyglycerin, trimethylolethane, trimethylolpropane, 1,3,5-pentanetriol, Erythritol, pentaerythritol, dipentaerythritol, sorbitol, sorbitan, sorbide, condensates of sorbitol and glycerin, polyhydric alcohols such as adonitol, arabitol, xylitol, mannitol, or partially etherified products thereof Or esterified products, xylose, arabinose, ribose, rhamnose, fructose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, melezitose, etc., or their partially etherified products or Examples include esterified products.
In the general formula X {O (AO) nR} m, the oxyalkylene group having 2 to 18 carbon atoms represented by AO is converted to ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, α-olefin oxide having 6 to 18 carbon atoms, or the like. It is derived from oxyethylene group, oxypropylene group, oxybutylene group, oxytetramethylene group, oxyalkylene group of 6 to 18 carbon atoms, etc. Random addition may be used.
In the above general formula, the hydrocarbon group having 1 to 18 carbon atoms represented by R is methyl group, ethyl group, allyl group, propyl group, isopropyl group, butyl group, isobutyl group, tertiary butyl group, amyl group, Isoamyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, isotridecyl, tetradecyl, hexadecyl, isocetyl, octadecyl, isostearyl, oleyl Benzyl group, cresyl group, butylphenyl group, dibutylphenyl group, octylphenyl group, nonylphenyl group, dodecylphenyl group, styrenated phenyl group and the like.
Similarly, as the acyl group having 2 to 18 carbon atoms represented by R, acetic acid, propionic acid, butyric acid, isobutyric acid, caproic acid, caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, myristic Examples include acyl groups derived from acids, palmitic acid, isopalmitic acid, margaric acid, stearic acid, isostearic acid, acrylic acid, methacrylic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid and the like.

  The amount of the shrinkage reducing agent used is preferably 1 to 10 parts, more preferably 2 to 8 parts, relative to 100 parts of cement. If it is less than 1 part, the shrinkage reduction effect is small, and if it exceeds 10 parts, strength development may be affected.

In the present invention, fibers can be blended and used for the purpose of improving the bending strength and initial crack resistance of the sprayed mortar.
Examples of the types of fibers include polymer fibers typified by vinylon fibers and propylene fibers, steel fibers, glass fibers, and inorganic fibers typified by carbon fibers, and are not particularly limited.
In the case of a non-converging type, the amount of the fiber used is preferably 0.1 to 1.5 parts by volume, more preferably 0.2 to 1.0 part by volume with respect to 1 m ^{3 of} cement mortar. If it is less than 0.1 volume part, the effect of improving the bending strength may not be exhibited, and if it exceeds 1.5 volume part, the fluidity of the mortar may be adversely affected. In the case of the convergence type, 0.03 to 0.5 volume part is preferable, and 0.05 to 0.3 volume part is more preferable. If it is less than 0.03 part by volume, it is difficult to suppress initial shrinkage cracking, and if it exceeds 0.5 part by volume, fluidity may be deteriorated. The length of the fiber is preferably 3 to 40 mm in consideration of pumping ability for both the convergent and non-convergent types.

  In this invention, it is possible to use together various cement admixtures, such as an antifoamer, a water repellent, an antibacterial agent, with a spraying material as needed.

  The amount of water to be mixed with the spray material of the present invention is preferably 10 to 22 parts with respect to 100 parts of mortar premixed with aggregate in consideration of the pumpability, sprayability and hardened properties of the mortar. 12-19 parts are more preferable. If it is less than 10 parts, it is difficult to ensure fluidity capable of pumping mortar, and if it exceeds 22 parts, strength development may be reduced. If it is the range of 10-22 parts, it can adjust to the moderate fluidity | liquidity suitable for pump pumping by using a fluidizing agent together.

  The spraying material construction method of the present invention is a method of mixing a spraying material and water, pumping the kneaded mortar with a pump, and joining and spraying compressed air in the middle of pumping. The method is not particularly limited.

  Examples will be described below.

180 parts of aggregate sand for 100 parts of cement, 6 parts of lightweight aggregate for 100 parts of sand, 5 parts of expansion material, 3 parts of shrinkage reducing agent, 100 parts of fluid for 100 parts of cement 0.1 part, 0.005 part of air entraining agent, 0.1 part of fiber (0.6 part by volume with respect to 1 m ^{3 of} cement mortar), 0.5 part of coagulation accelerator, pozzolanic fine powder, holmite mineral And / or the polymer thickener was added in the amount shown in Table 1 to prepare a dry cement mortar. The pozzolana fine powder was replaced with an aggregate. Add 16.5 parts of water to 100 parts of this dry cement mortar, knead with a bread mixer to make cement mortar, pump this with a squeeze pump, and join with compressed air before the discharge nozzle and spray. The rebound rate and thickness were measured. Thereafter, the mortar after spraying was collected in a 4 × 4 × 16 cm mold, demolded after 2 days of age, and the test specimen was in the atmosphere at a temperature of 20 ° C. and a humidity of 80% until the age of 28 days. Cured. Sealed with epoxy resin on the side and bottom of the test body, and applied on the top with a brush so that the amount of the solid-concentrated organic-inorganic composite coating agent shown in Table 1 is 150 g / m ² . An accelerated neutralization test and a chloride ion penetration test were performed. The results are also shown in Table 1.

(Materials used)
Cement: Ordinary Portland cement, commercially available aggregate (sand): dried lime sand from Aomi, Itoigawa City, Niigata Prefecture, bulk density 1.62g / cm ³ , maximum particle size 1.2mm
Lightweight aggregate: Chinese fly ash balloon, bulk density 0.42 g / cm ³ , maximum particle size 0.8 mm
Expansion material: calcium sulfoaluminate-based expansion material, commercial product shrinkage reducing agent: polyoxyalkylene derivative, HO— (CH ₂ CH ₂ O) ₁₈₉ -H, commercial product fluidizing agent: methylolmelamine-based fluidizing agent, commercial product Air entraining agent: Polyoxyethylene alkyl sulfate-based air entraining agent, commercial product fiber: vinylon fiber, fiber length 6 mm, fiber diameter 0.026 mm, convergence type, commercial product setting accelerator: sodium silicate, commercial product pozzolana fine powder : Granulated blast furnace slag, Blaine specific surface area 7500 cm ² / g, commercial holmite mineral: attapulgite, crystalline silica content less than 1%, commercial polymer thickener: hydroxyethyl methylcellulose, hydroxyethoxy group content 6% , Transmissivity 55% at 30 ° C., commercially available organic-inorganic composite coating agent: manufactured by Toagosei Co., Ltd., “CA2 2 ", acrylic resin - composite of fluorine mica, solid content concentration of 45%

(Test method)
Flowability (flow): A flow test defined in JIS R 5201 was performed.
Rebound rate: Mass percentage of the material dropped when sprayed for 2 minutes to a concrete precast plate installed on the ceiling and the total amount of mortar used for spraying.
Thickness: Thickness was evaluated when sprayed on a concrete U-shaped side groove lid of length 400 mm × width 600 mm × thickness 60 mm to a thickness of 90 mm. The presence or absence of falling or floating 24 hours after spraying was confirmed.
Accelerated neutralization test: The accelerated conditions were 5% carbon dioxide concentration, 30 ° C. temperature and 60% humidity. The organic-inorganic composite coating agent was applied and the accelerated test was started the next day. The promotion period was 28 days, and the neutralization depth from the top surface was measured by the phenolphthalein method.
Chloride ion penetration test: The coating depth was applied and the chloride ion penetration depth was measured by immersing in simulated seawater for 28 days according to JIS A 1171 the next day.
Ease of application: When the upper surface (4 × 16 cm) of the test specimen was applied with a brush, the case where the coating agent was uniformly applied was indicated as “◯”, the case where it was difficult to apply uniformly was indicated as “Δ”, and the case where it was not applied was indicated as “X”.

  From Table 1, in the present invention, the rebound ratio of the spray material is low, the thickness is good, it is easy to apply, and the neutralization of the composite in which the spray material is coated with the organic-inorganic composite coating agent. It can be seen that salt damage is significantly suppressed.

In the spray material of Experiment No. 1-4 of Example 1, with a brush so that the amount of the coating agent having a solid content concentration of the organic-inorganic composite coating agent shown in Table 2 is 150 g / m ² The procedure was the same as Example 1 except that the coating was performed. The results are also shown in Table 2.

  From Table 2, it can be seen that, in the present invention, the neutralization and salt damage of the composite in which the spray material is coated with the organic-inorganic composite coating agent is remarkably suppressed.

  In the spray material of Experiment No. 1-4 in Example 1, the solid content concentration of the organic-inorganic composite coating agent was set to 20%, and it was the same as Example 2 except that it was applied in the usage amount shown in Table 3. Went to. The results are also shown in Table 3.

  From Table 3, it can be seen that, in the present invention, the neutralization and salt damage of the composite in which the coating material is easy to apply and the coating material is coated with the organic-inorganic composite coating agent are remarkably suppressed.

  In the present invention, a composite that suppresses neutralization, salt damage, and the like can be obtained by applying an organic-inorganic composite coating film after spraying to a sprayable material that can be thickened. It can be widely applied to repair work in the construction field.

Claims (7)

Organic on the surface of the spray material containing cement, fine powder of pozzolana, formite mineral and / or polymer thickener, aggregate, fluidizing agent and / or air entraining agent, and setting accelerator -A composite comprising an inorganic composite coating film. The composite according to claim 1, wherein the aggregate is a spray material containing sand and a lightweight aggregate. Furthermore, the composite_body | complex of Claim 1 or 2 which is a spraying material containing at least 1 sort (s) chosen from an expansion material, a shrinkage | contraction reducing agent, and a fiber. The organic-inorganic composite type coating agent contains a synthetic resin aqueous dispersion, a water-soluble resin, and a swellable clay mineral, The composite according to any one of claims 1 to 3. The composite according to any one of claims 1 to 4, wherein the swellable clay mineral of the organic-inorganic composite coating agent is a synthetic fluoromica. 6. The composite according to claim 1, wherein the organic-inorganic composite coating agent is used in an amount of 50 to 500 g / m ² . The method for producing a composite according to any one of claims 1 to 6, wherein the surface of the spray material is coated with an organic-inorganic composite coating agent.