KR102281520B1 - Concrete structure surface protective material with excellent adhesion and durability, and concrete structure surface protection method using the same - Google Patents

Abstract

The present invention relates to a concrete structure surface protective agent composition having an eco-friendly neutralizing salt damage prevention and medium-type flame retardant function, and a surface protection method using the same. More specifically, the concrete structure surface protective agent composition uses fast-hardening cement as a main raw material to have a coefficient of thermal expansion similar to that of cement concrete and, at the same time, uses functional modified latex to provide high adhesion performance, thereby being integrated with a parent material. In addition, harmful substances such as organic solvents, heavy metals, and VOCs are not added and excellent performance in prevention of neutralization of a concrete structure and excellent abrasion resistance are provided, thereby providing an excellent effect of extending life of the structure. Excellent chemical performance such as neutralization prevention, salt damage prevention, and heavy corrosion protection, and excellent durability are provided, thereby providing an effect of reducing maintenance cost. The composition does not generate chemical smell during work to be installed in closed spaces or public places, thereby providing safety and eco-friendliness. The control structure surface protection method comprises a concrete structure surface protective agent composition manufacturing step, a surface treatment step, and an application step.

Description

Concrete structure surface protective material with excellent adhesion and durability, and concrete structure surface protection method using the same

The present invention relates to a concrete structure surface protection agent composition having excellent adhesion performance and durability, and a method for protecting the concrete structure surface using the same, and more particularly, coating and protecting the surface of a deteriorated corroded concrete structure using a fast-hardening binder and modified latex. It is related to the construction method to protect the structure.

In general, building structures, especially those made of concrete, when left in the concrete state without surface treatment, moisture penetrates through the microcracks that occur on the concrete surface, and in winter, the infiltrated moisture freezes, causing the volume to expand and crack. will promote In a cracked concrete structure, the strength of the concrete itself is lowered, and the internal reinforcing bars come into contact with moisture and corrode. If the internal rebars corrode, the strength of the concrete structure rapidly decreases, shortening the lifespan and reducing maintenance costs. As time goes by, the durability decreases and eventually loses its function as a building.

In particular, when it is built on the beach, it is often subjected to salt penetration, and when it is built in a factory wastewater area or sewage area, it is infiltrated by various chemicals, resulting in severe durability degradation. For example, when a concrete structure is in direct contact with an acidic atmospheric environment in which a large amount of sulfuric acid compounds such as hydrogen sulfide exist or acidic wastewater is present, deterioration of the structure may be accelerated.

In addition, erosion may occur due to deterioration of concrete structures due to acidic conditions created by the action of microorganisms in sewage treatment facilities or sewage conduits.

As a method for preventing the weakening of the durability of such a concrete structure, a method of applying an absorption inhibitor or a coating solution to the surface of the concrete is used. As a method of using the absorption inhibitor, an absorption inhibitor consisting of a paraffinic hydrocarbon compound or a fatty acid-based oil has been used, but the penetration depth is not easily secured and the effect on durability improvement is not large. As another method, a water repellent or absorption inhibitor prepared by diluting a silicone resin or oil in an organic solvent was used, but its use is currently limited due to the problem of pollution and adverse effects on the human body due to the nature of the solvent, which is fluid.

In addition, as the coating solution, a filler has been mixed with an acrylic resin-based polymer in the past, but there are insufficient aspects in terms of physical properties such as adhesion strength to the base concrete, durability, and compressive strength.

In particular, the existing coating method is basically a method of blocking moisture through the process of forming a film by an organic material, and the physical properties of the surface protectant itself can be highly evaluated due to the difference in the components of the fundamental material, but the protection of concrete due to this has limitations. This is because cement concrete, which is a typical inorganic material, and conventional surface protection agents (coatings), which are mainly made of epoxy and acrylic, which are commonly used, have a thermal expansion coefficient that is 10 times different, so considering the seasonal change, the life of the coating agent is not long. It has fundamental limitations.

Looking at the prior art related to the technology for protecting the surface of the cement concrete structure as follows.

First, Korean Patent Laid-Open Publication No. 2008-0094427 discloses that blast furnace slag, which has high affinity for iron and cement, is used as a filler to improve adhesion to a conductor, and to increase flexibility by adding a soft resin to prevent separation from a conductor surface. We have proposed a technology for a coating agent that can increase the vibration resistance by blocking it and increase the adhesion to the object by lowering the curing rate by using alkali metal hydroxide as a curing agent.

In addition, Korean Patent Registration No. 10-0937632 discloses that a fluorine-based surfactant having excellent antistatic properties and dust adhesion prevention properties is added to the surface of the coating film in order to solve the problem that the existing coating composition has poor resistance to contamination. We have proposed a technology for a coating agent that improves chemical and mold resistance.

However, the conventional coating agent has some advanced aspects in terms of adhesion strength, but lacks durability and chemical resistance, and it is necessary to further improve properties such as waterproofness and salt damage resistance, and also increase corrosion resistance and microorganisms in an acidic environment. In relation to the suppression technology for reproduction, there was a great need for the development of additional technology.

<Related prior art literature>

Republic of Korea Patent Registration No. 10-0632089

Republic of Korea Patent Registration No. 10-0167858

Republic of Korea Patent Registration No. 10-0536471

Republic of Korea Patent No. 100835842

The present invention was developed to solve the problems of the conventional surface protection agent (coating agent) as described above, and has a coefficient of thermal expansion similar to that of cement concrete using fast-hardening cement as the main raw material, and at the same time, it has high adhesion performance using functional modified latex. It enables integration with the base material, does not add harmful substances such as organic solvents, heavy metals, and VOCs, and is excellent in preventing neutralization of concrete structures, and has excellent wear resistance, so it has excellent effect of extending the life of the structure and neutralization. It has excellent chemical performance such as prevention, anti-salt and anti-corrosion functions, and excellent durability, which can reduce maintenance and reduce the odor of chemicals during operation, making it safe and eco-friendly as it can be installed in closed spaces or public places. An object of the present invention is to provide a surface protection agent composition having properties and a method for protecting the surface of a concrete structure using the same.

In order to achieve the above object, one embodiment of the present invention is

(a) preparing a coating composition for protecting the surface of a concrete structure, wherein the coating composition for protecting the surface of a concrete structure comprises 100 parts by weight of a fast-hardening binder, 30 to 50 parts by weight of a water-soluble modified latex, 1 to 10 parts by weight of an alkoxysilane hydrolyzate, an initiator 0.05 to 5 parts by weight, 0.05 to 5 parts by weight of an emulsifier,

1 to 10 parts by weight of a mixture of dihydrate gypsum and hemihydrate gypsum, 0.5 to 10 parts by weight of plaster, 0.5 to 10 parts by weight of anhydrite, 0.1 to 5 parts by weight of silica fume, 0.01 to 5 parts by weight of fly ash, 0.5 to 10 parts by weight of limestone, It contains a powder component comprising 0.01 to 5 parts by weight of slag,

Preparing a coating composition for protecting the surface of a concrete structure comprising 0.5 to 5 parts by weight of an activation accelerator and 0.5 to 5 parts by weight of a lithium-based reaction accelerator;

(b) arranging the construction target surface of the concrete structure using a surface treatment device; and

(c) applying and curing the coating composition for surface protection of the concrete structure prepared in (a) on the cleaned construction target surface;

It provides a protective coating method for the surface of a concrete structure comprising a.

In an embodiment of the present invention, the fast-hardening binder in step (a) is a mixture of Portland cement in a weight ratio of 100 and a mixture of calcium aluminate, calcium sulfoaluminate, magnesium aluminate and magnesium sulfoaluminate in a weight ratio of 20-50 characterized in that it consists of

In addition, in one embodiment of the present invention, the coating composition for surface protection of the concrete structure prepared in (a) is applied to the surface of the concrete construction in step (c) by using a painting, rolling or spraying method on the construction target surface and cured characterized by doing.

In addition, in one embodiment of the present invention, the water-soluble modified latex is acrylic resin 10-20 parts by weight, SBR (Styrene-Butadiene rubber) rubber 10-20 parts by weight, hydroxyl acrylate monomer 0.1-5 parts by weight, gallic acid 0.1 to 5 parts by weight, 15 to 30 parts by weight of an unsaturated polyester resin, 1 to 10 parts by weight of a metal cation, 0.5 to 5 parts by weight of a dispersant, and 40 to 70 parts by weight of water.

Further, in one embodiment of the present invention, the activity promoter is a chloride, carbonate, sulfate or oxalate containing an active polyvalent metal ion of calcium, magnesium, manganese or aluminum.

In addition, in one embodiment of the present invention, the lithium-based reaction accelerator is characterized in that at least one selected from lithium carbonate, lithium sulfate, and lithium hydroxide.

In addition, in one embodiment of the present invention, the coating composition for protecting the surface of a concrete structure is an antifoaming agent, a dispersing agent, a cationic wetting agent, a leveling agent, a surface tension reducing agent, a shrinkage reducing agent, a surface fluidity adjusting agent, a retarder, an antibacterial agent and an inorganic pigment. It is characterized in that it further comprises 1 to 5 parts by weight of one or more additives selected from the group consisting of.

In addition, in one embodiment of the present invention, the coating composition for protecting the surface of the concrete structure is selected from the group consisting of silicon dioxide (SiO2), barium sulfate (BaSO4), aluminum oxide (Al2O3), calcium carbonate (CaCO3) and talc It is characterized in that it further comprises 30-50 parts by weight of one or more fillers.

In addition, in one embodiment of the present invention, the coating composition for protecting the surface of the concrete structure is at least one selected from the group consisting of dodecylphenol, benzyl alcohol, propylene glycol monomethylether, and mixtures thereof. It is characterized in that it further comprises 10 to 20 parts by weight of a reactive diluent.

In addition, in one embodiment of the present invention, it is characterized in that the curing thickness is 50㎛ ~ 5mm in applying and curing the coating composition for protecting the surface of the concrete structure.

In addition, in one embodiment of the present invention, it is characterized in that a rubber latex-based rust converting agent is used as a primer before the coating composition for protecting the surface of the concrete structure is applied.

In addition, in one embodiment of the present invention, after applying the coating composition for protecting the surface of the concrete structure, it is characterized in that the top coat is additionally applied.

In addition, in one embodiment of the present invention, when the coating composition for surface protection of the concrete structure prepared in (a) is applied to the surface to be constructed on the concrete construction surface in step (c), a high-pressure airless mortar pump and a spray gun are provided It is characterized in that it is applied using a dedicated high-pressure spray equipment.

In addition, in one embodiment of the present invention, when applying the coating composition for surface protection of the concrete structure prepared in (a) to the surface of the concrete construction in step (c) to the surface to be constructed, it is applied using a roller or a brush, It can be applied using a safety vest for spraying coatings with a spray hose and spray gun attached to the vest.

At this time, the safety vest for spraying the coating agent attaches a leather reinforcing belt to the vest, and connects the safety belt for dispersing the weight of the hose to the reinforcing belt and the safety belt for dispersing the weight of the spray gun in the left and right directions, respectively, and the coating agent supply device Connecting a vest attachment hose of the same diameter and material as the hose connected to the reinforcing band, and having couplers at both ends of the vest attachment hose to the coating agent supply hose connected to the coating agent supply device and the supply hose connected to the spray gun It can be used by connecting each with a coupler connection method.

In addition, in one embodiment of the present invention, after step (c), it is characterized in that the acrylic urethane-based or siloxane-based water repellent is additionally coated.

The coating composition for protecting the surface of a concrete structure according to the present invention has the effect of significantly reducing defects due to the expression of strength greater than or equal to practical strength within 4 hours.

In addition, it has excellent adhesion and durability to the surface of the concrete structure, and in particular, properties such as chemical resistance, water resistance, and salt damage resistance are excellent, so that the surface protection effect of the concrete structure is excellent.

In addition, it has excellent corrosion resistance to an acidic environment, and in particular, the growth of microorganisms is suppressed, so that the problem of surface strength decrease due to microorganisms can be prevented, and it has the effect of improving weather resistance and surface strength, so the surface protection effect of the concrete structure is excellent and the effect is It has the advantage that it can be maintained for a long time.

In addition, it is excellent in preventing neutralization of the concrete structure to be coated, and has excellent wear resistance to extend the life of the structure. At the same time, it has excellent chemical performance such as neutralization prevention, salt damage prevention and heavy corrosion protection, and excellent durability, thereby reducing maintenance. It can be effective and there is no chemical smell, so it can be installed in a closed space or public place, so safety and eco-friendliness can be increased.

1 is a conceptual view schematically showing in detail an example of a safety vest used in a method for protecting the surface of a concrete structure according to the present invention.

Hereinafter, the present invention will be described in more detail.

The protective coating method for the surface of a concrete structure according to the present invention is configured in the following order. in other words,

(a) preparing a coating composition for protecting the surface of a concrete structure, wherein the coating composition for protecting the surface of a concrete structure comprises 100 parts by weight of a fast-hardening binder, 30 to 50 parts by weight of a water-soluble modified latex, 1 to 10 parts by weight of an alkoxysilane hydrolyzate, an initiator 0.05 to 5 parts by weight, 0.05 to 5 parts by weight of an emulsifier,

1 to 10 parts by weight of a mixture of dihydrate gypsum and hemihydrate gypsum, 0.5 to 10 parts by weight of plaster, 0.5 to 10 parts by weight of anhydrite, 0.1 to 5 parts by weight of silica fume, 0.01 to 5 parts by weight of fly ash, 0.5 to 10 parts by weight of limestone, It contains a powder component comprising 0.01 to 5 parts by weight of slag,

Preparing a coating composition for protecting the surface of a concrete structure comprising 0.5 to 5 parts by weight of an activation accelerator and 0.5 to 5 parts by weight of a lithium-based reaction accelerator;

(b) arranging the construction target surface of the concrete structure using a surface treatment device; and

(c) applying and curing the coating composition for surface protection of the concrete structure prepared in (a) on the cleaned construction target surface and curing;

First, the step of preparing the coating composition for protecting the surface of the concrete structure will be described.

The coating composition for surface protection of a concrete structure according to the present invention contains 100 parts by weight of a fast-hardening binder, 30-50 parts by weight of a water-soluble modified latex, 1-10 parts by weight of an alkoxysilane hydrolyzate, 0.05-5 parts by weight of an initiator, 0.05-5 parts by weight of an emulsifier including,

1 to 10 parts by weight of a mixture of dihydrate gypsum and hemihydrate gypsum, 0.5 to 10 parts by weight of plaster, 0.5 to 10 parts by weight of anhydrite, 0.1 to 5 parts by weight of silica fume, 0.01 to 5 parts by weight of fly ash, 0.5 to 10 parts by weight of limestone, It contains a powder component comprising 0.01 to 5 parts by weight of slag,

0.5 to 5 parts by weight of an activation accelerator and 0.5 to 5 parts by weight of a lithium-based reaction accelerator.

In the step (a), the fast-hardening binder may be a mixture of Portland cement in a weight ratio of 100 weight ratio and a mixture of calcium aluminate, calcium sulfoaluminate, magnesium aluminate and magnesium sulfoaluminate in a weight ratio of 20 to 50 weight ratio.

Specifically, general Portland cement (OPC) has about C ₃ S 51%, C ₂ S 25%, C ₃ A 9%, C ₄ AF 9%, CaSO ₄ 4%, and a specific surface area of 3,300 cm ² It is preferable to use a thing of /g before and after.

The calcium aluminate, calcium sulfoaluminate (CSA), magnesium aluminate and magnesium sulfoaluminate are cements having a relatively high alumina content compared to normal Portland cement, have excellent chemical resistance, and have the advantage of being usable in an acidic atmosphere. It is a type of super-fast cement with a short curing time, and is usually used in an appropriate ratio with Portland cement.

In addition, the fast-hardening binder may further include blast furnace slag powder in the range of about 1 to 10 parts by weight relative to 100 parts by weight of Portland cement, specifically, those ^{having a density of 2.85 to 2.95 g/m 3} It can be used .

Blast furnace slag is a latent hydraulic material that cannot initiate a self-triggered hydration reaction just by contact with water like ordinary Portland cement. The penetration of water is prevented and no further reaction occurs. However, when stimulated by alkalis (Ca(OH) ₂ , KOH, NaOH) and sulfates (CaSO ₄ ), the thin gel film is destroyed and it changes to a gel with an archipelago structure and begins to harden as ions are eluted and insoluble substances are precipitated from the blast furnace slag. However, when blast furnace slag is used in concrete, effects such as long-term strength improvement, watertightness improvement, hydration heat suppression and chemical resistance improvement can be seen compared to when only general portlant cement is used.

Next, in the present invention, the water-soluble modified latex is a synthetic resin-based emulsion latex, specifically 10 to 20 parts by weight of an acrylic resin, 10 to 20 parts by weight of SBR (Styrene-Butadiene rubber) rubber, 0.1 to 5 parts by weight of a hydroxyl acrylate monomer parts, unsaturated polyester resin 15-30 parts by weight, gallic acid 0.1-5 parts by weight, metal cation 1-10 parts by weight, dispersant 0.5-5 parts by weight, and water 40-70 parts by weight. desirable.

The acrylic resin is 2-hydroxyethyl methacrylic acid (2-HEMA: 2-hydroxyethyl methacrylate), methyl methacrylate (MMA: methyl methacrylate), n-butyl acrylate (n-BA: n-butyl acrylate) and A polyacrylate hybrid emulsion synthesized by adding any one acrylate monomer selected from acrylic acid (AAc) and an anionic or nonionic emulsifier and an initiator may be used. The acrylic resin dries quickly and exhibits excellent weather resistance, durability, and UV stability even under external exposure conditions, and is eco-friendly because it is water-soluble.

The SBR rubber preferably uses a resin having a solid content of 50% or more in order to maintain elasticity. It serves to prevent corrosion on the surface and is dispersed in a solvent, and also serves to increase the effect of gallic acid by dispersing and dissolving the gallic acid in a solution state. As the solvent, an ethylene glycol-based dihydric alcohol may be used.

The hydroxyl acrylate monomer serves to increase the crosslinking density to increase the network state, thereby improving physical properties. As the hydroxyl acrylate monomer, hydroxyl ethyl acrylate, hydroxyl propyl acrylate, hydroxyl ethyl methyl acrylate, and the like may be used.

The unsaturated polyester is formed by condensation polymerization of an acid and a glycol compound, for example, an acid value of 18 to 20 mg/KOH formed by the reaction of fumaric acid and diethylene glycol may be used. The unsaturated polyester serves to enhance the weather resistance, light resistance, and scratch resistance of the paint.

The gallic acid is a phenol carboxylic acid obtained by acid or alkali hydrolysis of tannin, and is a compound having a molecular formula of C7H6O5·H2O, and serves to improve the rust prevention and waterproofing properties of the surface.

The metal cation serves to strengthen the bondability with the internal primary and secondary paints, and as a specific example, one or two or more selected from Ca2+, Mg2+, Zn2+, Cu2+, Fe2+ may be used.

The dispersant is to form a uniform coating film by evenly dispersing the internal components in the liquid phase when the water-soluble latex is mixed, and in the present invention, one of the nonionic type polyoxyalkylene type surfactants or the anionic type polycarboxyl salt type surfactants. Any one selected can be used.

In the present invention, the alkoxysilane hydrolyzate may be obtained by forming silane in the form of silica gel through a sol-gel process, putting methyl methacrylate in the pores of the silica gel thus obtained, and then polymerizing and hydrolyzing it. In the present invention, the content of methyl methacrylate may be included in the range of 0.5 to 5 parts by weight based on 100 parts by weight of the alkoxysilane content.

In the present invention, the initiator is t-butyl peroxybenzoide, benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butylacetate, or 2,5-dimethylhexyl-2,5-diperoxy benzoate and the like can be used. In the present invention, the initiator is preferably used in the range of 0.05 to 5.0 parts by weight. When the content of the initiator is less than 0.05 parts by weight, the polymerization initiation reaction of the resin and the monomer is lowered, and consequently the strength characteristics of the coating agent are lowered. And, when it exceeds 5.0 parts by weight, there is a problem in that it is difficult to efficiently control the polymerization reaction.

In the present invention, the emulsifier serves to facilitate mixing of the coating agent with water when water is added to the coating composition for surface protection of a concrete structure according to the present invention. In the present invention, as the emulsifier, glycerin fatty acid ester, sorbitan fatty acid ester, or polyglycerol fatty acid ester may be used. In the present invention, the emulsifier is preferably used in the range of 0.05 to 5.0 parts by weight. When the content of the emulsifier is less than 0.05 parts by weight, there is a problem in that it is difficult to easily mix with water when the coating agent is mixed with water, and 5 parts by weight In the case of exceeding negative, there is a problem that strength and adhesion performance are difficult to be exhibited.

In the present invention, the dihydrate gypsum and hemihydrate gypsum serve to enhance durability by helping the formation of ethrinzite in the powder composition.

The dihydrate gypsum and hemihydrate gypsum are preferably included in the range of 1 part by weight to 10 parts by weight. When the content is less than 1 part by weight, there is a problem of lowering abrasion resistance and impact resistance, and when it exceeds 10 parts by weight, the strength is There is a problem with lowering.

In the present invention, the plaster (plaster) serves to easily mix the components included in the powder component with the liquid component. The plaster is preferably included in the range of 0.5 parts by weight to 10 parts by weight. Therefore, when the content of the plaster is less than 0.5 parts by weight, there is a problem in that it is difficult for the various components included in the powder component to be easily mixed with the liquid component. , When it exceeds 10 parts by weight, there is a problem in that strength and chemical resistance are lowered.

The anhydrite is a mineral corresponding to the anhydride of calcium sulfate, and serves to improve adhesion when the powder component and the liquid component are mixed. The anhydrite is preferably included in the range of 0.5 parts by weight to 10 parts by weight. When the content of the anhydrite is less than 0.5 parts by weight, the adhesion of the coating agent decreases, and when it exceeds 10 parts by weight, the chemical resistance decreases. there is a problem that

The silica fume is an amorphous active silica and has an average particle diameter of about 0.15 μm, and is a particle close to a perfect spherical shape. Silica fume improves water resistance and chemical resistance by the filling effect between powder component particles due to the characteristics of the spherical particles, and serves to improve the strength of the coating agent. In particular, silica fume also serves to improve the adhesion performance of the coating agent. The silica fume is preferably included in the range of 0.1 parts by weight to 5 parts by weight. When the content of silica fume is less than 0.1 parts by weight, there is a problem in that the waterproofing and chemical resistance of the coating agent is lowered and the strength is lowered, and 5 parts by weight If it exceeds the negative, there is a problem that cracks may occur.

The fly ash is the remaining components after burning coal in a facility that uses coal as fuel, such as thermal power plants, in the form of oxides remaining as fine dust of _{silicon oxide (SiO 2} ) or aluminum oxide (Al ₂ O _{3 ) components.} means that When the fly ash is mixed with the coating agent, workability is improved and long-term strength and watertightness are improved, which is economical. The fly ash is preferably included in the range of 0.01 parts by weight to 5 parts by weight. When the content of the fly ash is less than 0.01, the adhesion performance of the coating agent is reduced, and when it exceeds 5 parts by weight, the chemical resistance is lowered. there is

The limestone serves to auxiliaryly improve the adhesion of the coating composition for protecting the surface of a concrete structure according to the present invention. The limestone is preferably included in the range of 0.5 parts by weight to 10 parts by weight. When the content of the limestone is less than 0.5 parts by weight, the effect of improving the adhesion of the coating agent is reduced, and when it exceeds 10 parts by weight, the chemical resistance is lowered. there is a problem that

The slag is a by-product generated in the process of manufacturing steel in a steel mill, etc., and the main component of the slag is alumina silicate, and when mixed with a powder component, the slag serves to increase the durability and chemical resistance of the coating agent. In particular, slag has a low water permeability and serves to improve the waterproofness of the coating agent according to the present invention. The slag is preferably included in the range of 0.01 parts by weight to 5 parts by weight. When the content of the slag is less than 0.01 parts by weight, there is a problem in that durability, chemical resistance and waterproofness of the coating agent are deteriorated, and when it exceeds 5 parts by weight There is a problem in that the coating may crack and increase in weight.

In the present invention, the activity promoter is used to control the initial setting rate, and serves to activate the function of the coating agent and strengthen the adhesion performance, for example, active polyvalent metal ions of calcium, magnesium, manganese or aluminum. A chloride salt, carbonate salt, sulfate or oxalate salt containing may be used, and the amount thereof is preferably used in the range of 0.5 to 5 parts by weight.

In the present invention, the lithium-based reaction accelerator serves to promote the formation of cement hydrate after setting (termination), thereby affecting the strength expression and making the micropores dense, for example, lithium carbonate, lithium sulfate, lithium hydroxide, Lithium oxide, lithium chloride, lithium phosphate, lithium nitrate, lithium silicate, etc. may be used, and the amount thereof is preferably used in the range of 0.5 to 5 parts by weight.

In addition, one or more additives selected from the group consisting of an antifoaming agent, a dispersing agent, a cationic wetting agent, a leveling agent, a surface tension reducing agent, a shrinkage reducing agent, a surface fluidity regulator, a retardant, an antibacterial agent, and an inorganic pigment in the range of 1 to 5 parts by weight may include

In addition, in order to exhibit a flame retardant effect after coating, a flame retardant may be additionally included, and the flame retardant may be any one or a mixture of two or more of antimony molybdate, aluminum hydroxide, molybdenum oxide, and magnesium hydroxide. In particular, aluminum hydroxide (Al(OH) ₃ ) is converted to activated alumina when it is heated to 500℃ or higher and has adsorption performance, so it adsorbs harmful substances such as dioxin and hydrogen chloride gas (HCl) generated during combustion. It has an endothermic reaction to have a cooling effect and is non-flammable so that it has excellent water and acid resistance, and it can be expected to improve the flame retardant effect by using flame retardants in combination.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention may include a filler in the range of 30 to 50 parts by weight. The filler may have a particle diameter of 2 μm or less, and may be a group consisting of silicon dioxide (SiO2), barium sulfate (BaSO4), aluminum oxide (Al2O3), calcium carbonate (CaCO3), talc, or a mixture thereof.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention contains 10 to 20 non-reactive diluents selected from the group consisting of dodecylphenol, benzyl alcohol, propylene glycol monomethylether, and mixtures thereof. % by weight.

In the present invention, the coating composition for protecting the surface of the concrete structure may further include a functional filler.

As the functional filler, a mixture of silica powder and expandable graphite may be used.

As the silica powder, one or a mixture of two or more selected from colloidal silica, fumed silica, and micronized silica may be used.

The functional filler serves to increase the physical effect by serving to further increase the binding effect of the surface protection agent (coating agent) composition. In the present invention, the mixing ratio of the silica powder and the expandable graphite is preferably mixed in a weight ratio of 100:50 to 200.

In addition, when using the coating composition for concrete surface protection, it can be used alone, but in areas requiring a high level of neutralization prevention, chloride ion permeation resistance, and water permeability resistance, the surface is treated with organosilane and finished to increase the water repellency effect. High durability can be expected due to this.

That is, silica powder alone or a mixture of expandable graphite powder is dispersed in a solvent in a colloidal solution dispersed in organic silane, and then the treatment can be performed by stirring for about 1 to 10 hours. Specifically, based on 100 parts by weight of silica powder alone or a mixture solution of expandable graphite powder, about 0.1-50 parts by weight of organic silane is added to the solution to form organic groups on the surface of the powder particles in the solution, and passes through a reactor for dehydration and condensation reaction to form a powder surface-treated with organic groups. In this case, the solution is silica powder or expandable graphite powder dispersed in a colloidal state in a solvent such as water or alcohol, and it is preferable to contact the organic silane in a colloidal solution state.

Specific examples of the organosilane include dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and tetraethoxysilane. At this time, in the case of treating the surface of the powder with organic silane, stirring is performed at room temperature for 1 to 10 hours to form an inorganic material having organic groups and passing it through a reactor. At this time, the reactor is a heating device, and the temperature is raised to 100 ~ 300 ℃, the solvent and the inorganic material formed with an organic group for 1 ~ 10 hours to dehydrate and condensation reaction, the surface-treated inorganic particles can be prepared.

The silica powder and expandable graphite powder prepared as described above have excellent binding effect because silane is formed on the surface, and thus durability may be further improved.

In the present invention, the functional filler is preferably included in the range of 0.1 to 10 parts by weight.

Concrete surface protection construction according to the present invention is carried out by using the coating composition for surface protection of concrete structures prepared in such a composition.

First, the surface to be constructed of the concrete structure is cleaned using a surface treatment device.

Specifically, clean the construction surface of the concrete to be repaired so that there are no foreign substances, and after washing with high-pressure water spray, the concrete repair material (mortar) is filled in the dents or dropped offs to proceed with leveling. At this time, if there is an exposed reinforcing bar, it is preferable to first pretreat the reinforcing bar using a separate rust preventive agent.

After the filling operation is completed, the coating composition for surface protection of the concrete structure according to the present invention prepared above on the concrete construction surface is applied to the construction target surface using a method such as painting, rolling or spraying, and the construction is completed by curing.

The coating composition for protecting the surface of a concrete structure according to the present invention is excellent in durability, weather resistance, surface strength and water resistance strengthening effect only by one application, but in order to optimally exhibit its function, it is preferable to reapply it 2-3 times. In the present invention, the coating composition for surface protection of the concrete structure ^{is preferably applied at a rate of 20 to 1000 g/m 2} , and the applied thickness is preferably applied to a thickness of 50 μm to 5 mm when cured.

At this time, painting, rolling, or spraying methods can be used to apply the coating composition for surface protection of the concrete structure to the surface to be constructed. In the winter season, drying and curing are usually carried out for about 24 hours.

In addition, in the present invention, since the coating agent itself has a certain degree of rust prevention function, it can exhibit rust prevention properties without using a separate primer, but when the surface rust is exposed, a primer is applied and the coating agent according to the invention is applied. it is preferable

As the primer used in the present invention, a rubber latex-based rust converter can be used, and it is preferable to use a rust converter that does not contain an organic solvent.

In addition, in the present invention, after applying the coating composition for protecting the surface of the concrete structure, a top coat may be additionally applied. In this case, the topcoating agent used is not particularly limited, and the topcoating agent generally used in the technical field to which the present invention belongs may be used without limitation.

In addition, in the present invention, when applying the coating composition for surface protection of the concrete structure prepared in (a) to the concrete construction surface in the step (c) to the construction target surface, a high-pressure airless mortar pump and dedicated high-pressure spraying equipment equipped with a spray gun It is preferable to apply using

This is because the coating composition for protecting the surface of a concrete structure according to the present invention contains a lot of binder components and has a high viscosity, so a high-pressure airless mortar pump and a spray gun (special nozzle equipped and high-pressure spraying pressure possible) are provided rather than general spray equipment. Because it is better to use spray equipment.

In this case, the dedicated high-pressure spraying equipment may use special equipment designed to reduce dust by having a dust reduction device around the nozzle in an elongated vertical shape.

In addition, in the present invention, when the coating composition for surface protection of the concrete structure prepared in (a) is applied to the surface to be constructed on the concrete construction surface in step (c), it is applied using a roller or a brush, or a spray hose and a vest It can be applied using a (exclusive) safety vest for spraying coatings with a spray gun attached.

1 is a conceptual view schematically showing in detail an example of a safety vest used in a method for protecting the surface of a concrete structure according to the present invention.

As shown in Figure 1, in the present invention, the safety vest for spraying the coating agent attaches a leather reinforcing belt to the vest, and a safety belt for dispersing the weight of the hose to the reinforcing belt and a safety belt for dispersing the weight of the spray gun in the left and right directions, respectively to the reinforcing band, and a vest attached hose of the same diameter and material as the hose connected to the coating agent supply device (the vest attached hose is preferably disposed on the back side for workability) to the reinforcing band, and the Couplers are provided at both ends to be used by connecting a coating agent supply hose connected to the coating agent supply device and a supply hose connected to the spray gun in a coupler connection method, respectively.

When using such a safety vest for spraying coatings, stability can be strengthened by attaching a hose to the vest, fatigue can be reduced during spray work, and the connection between the hose and the vest is installed on the left and right sides instead of the front and back of the waist This can prevent the operator from tripping over the hose while moving, and since the spray gun and the vest are connected, it has the effect of preventing the spray gun from falling and being damaged. Because it is connected, there is no need for the operator to drag the hose by hand, which makes work easier.

In addition, in the present invention, after step (c), a water repellent coating agent may be additionally coated, and an acrylic urethane-based or siloxane-based water repellent may be used as the water-repellent coating agent.

Above, the coating composition for protecting the surface of a concrete structure according to the present invention and a method for protecting the surface of a concrete structure using the same have been described in detail.

The coating composition for protecting the surface of a concrete structure according to the present invention can be used to protect the surface of a concrete structure in various fields, and can also be used to protect the surface of slabs, beams, columns, walls, and floors, and has strong resistance to salt damage, so slabs in ports , beams, columns, and chloride ion penetration prevention, piers and columns of underwater structures such as ship docks and breakwaters, waterways, rock walls, and other offshore structures, etc. It can also be used in treatment plants and the like.

The coating composition for protecting the surface of a concrete structure according to the present invention serves to improve the durability of the concrete structure by inhibiting penetration of deterioration substances such as salt and acidic substances, and has excellent compatibility with the mortar surface.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention has excellent adhesion to the existing base material, no neutralization reaction with concrete, water resistance, ozone resistance, chemical resistance, waterproofness, breathability, a phenomenon of aging by oxidation by ultraviolet rays The advantage is that this does not occur.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention has excellent breathability, does not cause condensation, does not oxidize the surface of the structure, has excellent permeability, and has a dense density due to hardening of the penetrated product, durability, It has excellent waterproofness, and it prevents cracking of the main body, which is repeatedly contracted and expanded according to temperature change, and has excellent elasticity, so it is very suitable for work in the vibrating part.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention is excellent in abrasion resistance and impact resistance due to strength expression, and blocks the penetration of carbon dioxide and blocks water penetration. In the present invention, the coating composition for surface protection of concrete structures is environmentally friendly with low VOC (volatile organic compound) content, no air pollution, high strength expression, excellent early strength, and the same cement as concrete is the main material. It behaves the same as the parent material

In addition, the coating composition for surface protection of a concrete structure according to the present invention has excellent water resistance, weather resistance, chemical resistance, and contamination resistance, and can protect the mother body and the finished surface from chemical gas, exhaust gas, rainwater, etc. shows a great effect.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention is excellent in high elasticity, smoothness, low-temperature stability (cracking resistance), odorless, and exhibits a good dispersion action even when mixed with water, and maintains uniform strength as a whole and high strength am. In addition, it forms high-density and dense tissue by good dispersing action of powder components, so it has excellent chemical resistance (salt resistance, acid resistance) and suppresses penetration of water, oil, etc.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention has excellent adhesion to concrete, is excellent in both short-term adhesion strength and long-term stability, and has the advantage that cracks do not occur due to an appropriate balance of strength and stability.

In addition, the coating composition for protecting the surface of a concrete structure according to the present invention has excellent corrosion resistance to an acidic environment and, in particular, inhibits the growth of microorganisms, so that the problems of surface strength reduction and surface contamination caused by microorganisms can be prevented, and weather resistance and surface strength improvement effect It has the advantage that the surface protection effect of the concrete structure is excellent and the effect can be maintained for a long time.

Hereinafter, the present invention will be described in more detail based on Examples. However, the scope of the present invention is not limited by the following examples.

[Example]

Example 1

A binder was prepared by mixing 30 parts by weight of an aluminate mixture (calcium aluminate, calcium sulfoaluminate, magnesium aluminate and magnesium sulfoaluminate) with 50 parts by weight of general Portland cement (OPC), and an acrylic resin (30 weight ratio 0, Water-soluble modified latex obtained by mixing SBR rubber (30 weight ratio), unsaturated polyester resin (20 weight ratio), hydroxyl acrylate monomer (1 weight ratio), metal cation (3 weight ratio) and dispersing agent (1 weight ratio) and mixing water 40 After mixing parts by weight, 5 parts by weight of a mixture of dihydrate gypsum and hemihydrate gypsum, 5 parts by weight of plaster, 5 parts by weight of anhydrite, 3 parts by weight of silica fume, 3 parts by weight of fly ash, 7 parts by weight of limestone, and 3 parts by weight of slag , 1.0 parts by weight of an activity accelerator and 1.0 parts by weight of a reaction accelerator (a mixture of lithium carbonate, lithium sulfate, and lithium hydroxide), a dispersant, a shrinkage reducer, a retarder, an inorganic pigment, and a filler were mixed in a certain amount to prepare a coating composition .

Comparative Example 1

40 parts by weight of SBR latex resin and 30 parts by weight of a fast-diameter binder as a powder component, 5 parts by weight of gypsum, 5 parts by weight of plaster, 3 parts by weight of silica fume, 3 parts by weight of fly ash, 7 parts by weight of limestone, 3 parts by weight of slag A coating composition was prepared by mixing a predetermined amount of a pigment, a filler, a shrinkage reducing agent, a retarder, and the like.

Comparative Example 2

35 parts by weight of acrylic latex resin, 5 parts by weight of gypsum, 5 parts by weight of plaster, 5 parts by weight of anhydrite, 3 parts by weight of silica fume, 3 parts by weight of fly ash, 7 parts by weight of limestone, and 3 parts by weight of slag are mixed, and the dispersant , a shrinkage reducing agent, a retarder, an inorganic pigment, and a predetermined amount of additives such as a filler were mixed to prepare a coating composition.

Comparative Example 3

30 parts by weight of styrene monomer, 5 parts by weight of t-butylperoxybenzoide and 5 parts by weight of glycerin fatty acid ester are mixed, and then gypsum 5 parts by weight, plaster 5 parts by weight, anhydrite 5 parts by weight, silica fume 3 parts by weight, fly A coating composition was prepared by mixing 3 parts by weight of ash, 7 parts by weight of limestone, and 3 parts by weight of slag, and mixing a certain amount of additives such as a dispersant, a shrinkage reducing agent, a retarder, an inorganic pigment, and a filler thereto.

Comparative Example 4

30 parts by weight of normal butyl acrylate and 5 parts by weight of glycerin fatty acid ester are mixed, and here again 5 parts by weight of gypsum, 5 parts by weight of plaster, 5 parts by weight of anhydrite, 3 parts by weight of silica fume, 3 parts by weight of fly ash, 7 parts by weight of limestone A coating composition was prepared by mixing parts by weight and 3 parts by weight of slag, and mixing a certain amount of additives such as a dispersant, a shrinkage reducing agent, a retarder, an inorganic pigment, and a filler thereto.

performance evaluation

1. Chloride ion penetration resistance, freeze-thaw resistance test

Chloride ion penetration resistance and freeze-thaw resistance of the coatings for surface protection of concrete structures prepared according to Example 1 and Comparative Examples 1 to 4 were measured.

The chloride ion penetration resistance was measured according to the standard of KS F 4936-2008 after 28 days of construction, and the freeze-thaw resistance was measured according to the standard of KS F 2456-2013 after 28 days of construction, and the results are shown in Table 1 below. It was.

Sample Chloride ion penetration resistance
(Coulombs) Freeze-thaw resistance
(relative dynamic modulus) (%) Example 1 425 84.5 Comparative Example 1 440 65.8 Comparative Example 2 460 55.5 Comparative Example 3 520 60.0 Comparative Example 4 458 68.1

Referring to Table 1, the coating composition for protecting the surface of a concrete structure according to the present invention is equivalent to or superior to that of the conventional coating agent in terms of chloride ion penetration resistance and freeze-thaw resistance.

2. Waterproof test

The waterproofness of the coating agent for protecting the surface of the concrete structure prepared according to Example 1 and Comparative Examples 1 to 4 was measured.

The water permeability, water absorption coefficient, moisture permeation resistance and length change rate were measured according to the standards of KS F 4042-2012 after 28 days of construction, and the results are shown in Table 2 below.

Sample pitch
(g) water absorption coefficient
(kg/m ² h ^0.5 ) moisture permeation resistance
(m) length change rate
(%) Example 1 0.20 0.05 0.9 -0.011 Comparative Example 1 0.31 0.07 1.2 -0.012 Comparative Example 2 0.25 0.06 1.1 -0.012 Comparative Example 3 0.29 0.07 1.0 -0.013 Comparative Example 4 0.32 0.06 1.2 -0.012

Referring to the results of Table 2, it can be seen that the degree of moisture permeation was reduced in Example 1 compared to Comparative Examples 1 to 4. This is interpreted as a result of showing the excellent waterproof performance of the coating composition for protecting the surface of a concrete structure according to the present invention.

3. Chemical resistance test

Chemical resistance of the coating composition for protecting the surface of a concrete structure prepared according to Example 1 and Comparative Examples 1 to 4 was measured.

The measurement method was to treat the coating layer with a salinity of 35‰ and a solution of sulfuric acid with a concentration of 2% for 1 hour every day on the coating layer 28 days after curing on the concrete structure, respectively, and then whether the coating layer was damaged for 60 days in units of 1 day. Confirmed.

The results are shown in Table 3 below.

Sample Chemical resistance test (days) brine sulfuric acid solution Example 1 - 80 Comparative Example 1 - 50 Comparative Example 2 20 5 Comparative Example 3 35 10 Comparative Example 4 40 15

Looking at Table 3, in the case of Example 1 and Comparative Example 1, the surface damage did not occur at all by the brine treated for 60 days, but in the case of Comparative Examples 2 to 4, the surface damage occurred 20 to 40 days after the brine treatment. it can be seen that In addition, when the sulfuric acid solution was treated, it was confirmed that the surface damage did not occur for 80 periods in Example 1, but in Comparative Example 1, the acid resistance to the sulfuric acid solution was lower than in Example 1, and Comparative Example In the case of 2 to 4, it can be confirmed that the surface damage occurred within 5 to 15 days.

This is interpreted as a result supporting the excellent chemical resistance, particularly acid resistance, of the coating composition for protecting the surface of a concrete structure according to the present invention.

4. Weather resistance, stain resistance

Weather resistance and stain resistance of the coating composition for protecting the surface of a concrete structure prepared according to Example 1 and Comparative Examples 1 to 4 were measured.

Weather resistance was evaluated according to the accelerated weather resistance test method of KS M 5000-3231.

For stain resistance, spray carbon black dispersed at 20% in water and solvent (mineral spirit) on the specimen, immerse it at 80±2°C for 5 hours, and dry it. Then, apply the carbon-coated side to running water and wash it down naturally. Water washability was evaluated by the method of visually observing the state remaining after.

The results are shown in Table 4 below.

Sample accelerated weathering
(ΔE) stain resistance Example 1 0.2 Good Comparative Example 1 0.3 Good Comparative Example 2 0.5 Inadequate Comparative Example 3 0.5 Inadequate Comparative Example 4 0.4 Inadequate

Referring to Table 4, Example 1 and Comparative Example 1 were excellent in weather resistance and stain resistance. On the other hand, Comparative Examples 2 to 4 showed poorer results than that of Example 1 in terms of weather resistance and stain resistance. Therefore, it can be confirmed that when the coating composition according to the present invention is used, it is superior to the conventional coating agent in terms of weather resistance and stain resistance.

4. Coefficient of thermal expansion

The thermal expansion coefficient of the coating composition for surface protection of the concrete structure prepared according to Example 1 and general concrete was measured.

The measurement was performed using the method of ASTM 531-18, and the results are shown in Table 5 below.

Example 1 concrete coefficient of thermal expansion 10.4×10 ^-6 /℃ 10.0×10 ^-6 /℃

As shown in Table 5, Example 1 according to the present invention has a coefficient of thermal expansion similar to that of concrete, and thus, despite seasonal temperature changes, phenomena such as peeling and cracking due to the difference in thermal behavior with the base concrete can be improved

Claims (16)

(a) preparing a coating composition for protecting the surface of a concrete structure, wherein the coating composition for protecting the surface of a concrete structure comprises 100 parts by weight of a fast-hardening binder, 5 to 10 parts by weight of a water-soluble modified latex, 1 to 10 parts by weight of an alkoxysilane hydrolyzate, an initiator 0.05 to 5 parts by weight, 0.05 to 5 parts by weight of an emulsifier,
1 to 10 parts by weight of a mixture of dihydrate gypsum and hemihydrate gypsum, 0.5 to 10 parts by weight of plaster, 0.5 to 10 parts by weight of anhydrite, 0.1 to 5 parts by weight of silica fume, 0.01 to 5 parts by weight of fly ash, 0.5 to 10 parts by weight of limestone, It contains a powder component comprising 0.01 to 5 parts by weight of slag,
Preparing a coating composition for protecting the surface of a concrete structure comprising 0.5 to 5 parts by weight of an activation accelerator and 0.5 to 5 parts by weight of a lithium-based reaction accelerator;
(b) arranging the construction target surface of the concrete structure using a surface treatment device; and
(c) applying and curing the coating composition for surface protection of the concrete structure prepared in (a) on the cleaned construction target surface,
The water-soluble modified latex is 10-20 parts by weight of acrylic resin, 10-20 parts by weight of SBR (Styrene-Butadiene rubber) rubber, 0.1-5 parts by weight of hydroxyl acrylate monomer, 15-30 parts by weight of unsaturated polyester resin, 0.1 gallic acid - 5 parts by weight, 1-10 parts by weight of metal cations, 0.5-5 parts by weight of a dispersant, and 40 to 70 parts by weight of water A protective coating method for the surface of a concrete structure, characterized in that it is comprised.
The method according to claim 1, wherein the fast-hardening binder in step (a) consists of a mixture of Portland cement in a weight ratio of 100 weight ratio and a mixture of calcium aluminate, calcium sulfoaluminate, magnesium aluminate and magnesium sulfoaluminate in a weight ratio of 20 to 50 weight ratio. A protective coating method for the surface of a concrete structure.
The method according to claim 1, Concrete characterized in that the coating composition for surface protection of the concrete structure prepared in (a) is applied to the concrete construction surface in the step (c) by using a painting, rolling or spraying method on the surface to be constructed and then hardened. Protective coating method on the structure surface.
delete The method according to claim 1, wherein the activity promoter is a chloride, carbonate, sulfate or oxalate containing active polyvalent metal ions of calcium, magnesium, manganese or aluminum.
The method according to claim 1, wherein the lithium-based reaction accelerator uses at least one selected from lithium carbonate, lithium sulfate, and lithium hydroxide.
The method according to claim 1, wherein the coating composition for protecting the surface of the concrete structure is selected from the group consisting of an antifoaming agent, a dispersing agent, a cationic wetting agent, a leveling agent, a surface tension reducing agent, a shrinkage reducing agent, a surface fluidity adjusting agent, a retarder, an antibacterial agent and an inorganic pigment. Protective coating method for the surface of a concrete structure, characterized in that it further comprises 1 to 5 parts by weight of more than one additive.
The method according to claim 1, The coating composition for surface protection of the concrete structure is silicon dioxide (SiO2), barium sulfate (BaSO4), aluminum oxide (Al2O3), calcium carbonate (CaCO3) and one or more fillers selected from the group consisting of talc 30~ Protective coating method for the surface of a concrete structure, characterized in that it further comprises 50 parts by weight.
The method according to claim 1, wherein the coating composition for protecting the surface of the concrete structure is at least one non-reactive diluent selected from the group consisting of dodecylphenol, benzyl alcohol, propylene glycol monomethylether, and mixtures thereof 10 to 20 wt. Protective coating method for the surface of a concrete structure, characterized in that it further comprises a part.
The method according to claim 1, wherein the curing thickness of the coating composition for surface protection of the concrete structure is 50㎛ ~ 5mm in applying and curing the protective coating method for the surface of the concrete structure.
The method according to claim 1, wherein a rubber latex-based rust converting agent is used as a primer before the coating composition for protecting the surface of the concrete structure is applied.
The method according to claim 1, wherein after applying the coating composition for protecting the surface of the concrete structure, a top coater is additionally applied.
The method according to claim 1, When the coating composition for surface protection of the concrete structure prepared in (a) is applied to the surface of the concrete construction surface in step (c), a dedicated high-pressure spray equipment equipped with a high-pressure airless mortar pump and a spray gun is used. A protective coating method for the surface of a concrete structure, characterized in that it is applied by
The method according to claim 1, In step (c), when the coating composition for surface protection of the concrete structure prepared in (a) is applied to the surface to be constructed on the concrete construction surface in step (c), it is applied using a roller or a brush, or a spray hose and spraying to a vest A protective coating method for the surface of a concrete structure, characterized in that it is applied using a safety vest for spraying a coating agent with a gun attached.
The method according to claim 14, wherein the safety vest for spraying the coating agent attaches a leather reinforcing belt to the vest, and connects the safety belt for dispersing the weight of the hose to the reinforcing belt in the left and right directions, respectively, and the coating agent Connecting a vest attachment hose of the same diameter and material as the hose connecting to the supply device of the reinforcing band, and having couplers at both ends of the vest attachment hose, connected to the coating agent supply hose connected to the coating agent supply device, and the spray gun Protective coating method for the surface of a concrete structure, characterized in that it is connected to each supply hose in a coupler connection method.
The method according to claim 1, wherein after the step (c), an acrylic urethane-based or siloxane-based water repellent is additionally coated.

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