KR101447124B1 - Composition for protecting the surface of concrete structure having salt resistance, freezing resistanc and wear resistance and repairing method of concrete structure using the composite - Google Patents

Abstract

The present invention relates to a composition for protecting the surface of a concrete structure and a method for repairing a concrete structure using the same, wherein the composition includes 5-90 wt% of a liquid binder and 10-95 wt% of an inorganic binder, and the liquid binder includes 40-99 wt% of polystyrene-acrylate, 0.1-40 wt% of methylmethacrylate-butadiene, 0.1-30 wt% of urethane acryl oligomer, 0.1-20 wt% of polyvinylacetate-vinylversatate, 0.01-20 wt% of polyvinyl propionate, and 0.01-15 wt% of a fluorine resin. By means of the present invention, the composition has excellent fluidity, elasticity, adhesive forces, bending strength, tensile strength, attaching strength, and durability, and the composition can have improved bending ductility, waterproofing properties, and surface hardness. In particular, the composition has excellent salt resistance, freezing and thawing resistance, and wear resistance. Early strength can be expressed, so that a construction period is reduced and a traffic opening time is reduced.

Description

TECHNICAL FIELD The present invention relates to a composition for protecting a surface of a concrete structure which is excellent in flame retardancy, resistance to freezing and thawing and abrasion resistance, and a method for repairing a concrete structure using the same. }

The present invention relates to a composition for protecting a surface of a concrete structure and a method for repairing a concrete structure using the same. More particularly, the present invention relates to a composition for protecting a surface of a concrete structure, Which is excellent in flame retardancy, resistance to freezing and thawing, and abrasion resistance and can exhibit early strength to shorten the construction time to reduce the opening time of the concrete, and a concrete structure repairing method using the same It is about the construction method.

The deterioration of the performance of the concrete structure means that the concrete fails to exert its original function and deteriorates its characteristics over time due to neutralization, salt corrosion, frost damage, chemical erosion, alkali aggregate reaction, fatigue and weathering. Concrete should be repaired and reinforced regularly, because the performance of the concrete gradually deteriorates after a certain period of time after casting or molding. The deterioration of the performance of the concrete is a crack, and when cracks occur, harmful outside air, moisture and chemical components permeate inside the concrete, thereby further deteriorating the performance of the concrete. In addition, due to the corrosion of the reinforcing bars inside the concrete structure due to moisture and chloride ions penetrating into the concrete, additional cracks occur or concrete falls off, and at the same time, the reinforcing steel section is reduced by the corrosion of the reinforcing bars, The structure may be damaged.

On the other hand, when cracks occur in the concrete due to deterioration of the concrete structure, in particular, the concrete slab of the bridge, the road surface, the lower portion of the bridge portion and the sewer culvert portion, the compressive strength of the concrete gradually decreases and the tensile strength of the reinforcing bar gradually decreases. The concrete exposed through the site is subjected to neutralization and corrosion of the reinforcing steel occurs. If these rebar corrosion phenomena become severe, the concrete structure may eventually collapse. Research and development of materials and methods for repairing and repairing areas where corrosion and erosion are frequently occurring are being continuously studied.

Korea Patent Registration No. 10-1094755

SUMMARY OF THE INVENTION The object of the present invention is to provide a resin composition which is excellent in high flowability, elasticity, adhesive strength, bending strength, tensile strength, adhesion strength and durability and can improve flexural toughness, waterproofness and surface hardness, The present invention provides a composition for protecting the surface of a concrete structure and a method for repairing a concrete structure using the same, which is excellent in abrasion resistance and can exhibit early strength to shorten a construction period to reduce traffic opening time.

The present invention relates to an inkjet recording material comprising 5 to 90% by weight of a liquid binder and 10 to 95% by weight of an inorganic binder, wherein the liquid binder comprises 40 to 99% by weight of polystyrene-acrylate, 0.1 to 40% by weight of methyl methacrylate- 0.1 to 30% by weight of an acrylic oligomer, 0.1 to 20% by weight of polyvinyl acetate-vinyl versatate, 0.01 to 20% by weight of polyvinyl propionate and 0.01 to 15% by weight of a fluorine resin. Lt; / RTI >

Wherein the liquid phase binder is selected from the group consisting of mono-tert-butyl-hydroquinone, p-benzoquinone, tertiary butyl catechol, tolu-halide quinone, hyroquinone, hydroquinone monomethyl ether and mono-tert-butyl- 0.01 to 2% by weight of a substance or more.

In addition, the liquid binder may further include 0.01 to 5% by weight of wax.

The liquid binder may further include 0.01 to 10 wt% of a smoothing agent for improving self-leveling property.

The liquid binder may further include 0.01 to 10% by weight of hydroxyethylcellulose.

The inorganic binder is usually 25 to 75 wt% of Portland cement, 5 to 30 wt% of hard calcium carbonate, 5 to 35 wt% of calcium aluminate, 0.1 to 15 wt% of magnesium oxide, 1 to 30 wt% of blast furnace slag, By weight of aluminum oxide, 0.01 to 20% by weight of aluminum powder, 0.01 to 10% by weight of bentonite, 0.1 to 15% by weight of titanium oxide and 10 to 63% by weight of silica silica.

The inorganic binder may further include 0.01 to 5% by weight of a retarder for delaying rapid curing in order to ensure workability.

The present invention also relates to a method for manufacturing a concrete slab and a concrete structure for protecting a concrete slab and a concrete structure after confirming the moisture content of the cleaned area by chipping and removing the laitance and impurities of the concrete slab surface by a planer, Applying a primer for improving the adhesion of the concrete structure, and applying the composition for protecting the surface of the concrete structure to the upper portion coated with the primer.

The primer may include at least one material selected from the group consisting of the liquid binders, styrene-butadiene, polyethylene vinyl acetate, and acrylic.

According to the composition for protecting the surface of a concrete structure of the present invention, the use of a liquid binder improves fluidity, elasticity, adhesive force, flexural strength, tensile strength and durability. Further, by using the liquid binder, the flexural toughness, waterproofness and surface hardness can be improved. Also, by using the liquid binder, the early strength of the composition for protecting the surface of the concrete structure can be developed, thereby shortening the construction period and reducing the traffic opening time.

Further, according to the composition for surface protection of concrete structures of the present invention, effects such as improvement of flame retardancy, development of long-term strength, improvement of durability, suppression of temperature rise and improvement of abrasion can be obtained by using inorganic binder have.

The composition for surface protection of concrete structures of the present invention is particularly excellent in flame retardancy, freeze-thaw resistance and abrasion resistance.

Hereinafter, preferred embodiments according to the present invention will be described in detail. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not.

The composition for protecting a concrete structure according to a preferred embodiment of the present invention comprises 5 to 90% by weight of a liquid binder and 10 to 95% by weight of an inorganic binder.

The liquid phase binder is used to improve pot life, workability, fluidity, elasticity, flexural strength, tensile strength, durability, flexural toughness, waterproofness and surface hardness. The liquid-phase binder preferably comprises 40 to 99% by weight of polystyrene-acrylate, 0.1 to 40% by weight of methyl methacrylate-butadiene for improving the adhesion and toughness, and an elasticity and durability for improving the strength and durability 0.1 to 20% by weight of polyvinyl acetate-vinyl versatate for improving ductility and adhesion, 0.01 to 20% by weight of polyvinyl propionate for improving durability, and strength improvement And 0.01 to 15% by weight of a fluorine resin for preventing contamination.

It is preferable that the liquid binder is contained in the concrete structure surface protective composition in an amount of 5 to 90% by weight. If the content of the liquid phase binder exceeds 90% by weight, the viscosity is lowered and the material is easily separated, and the price competitiveness may be lowered. If the content of the liquid binder is less than 5% by weight, the effect of improving the high flow performance, strength, durability, toughness, water resistance and surface hardness may be insignificant.

The polystyrene-acrylate is used to induce bonding between minerals and to improve strength and durability. When the content of the polystyrene-acrylate is less than 40% by weight, the effect of inducing the bonding of the inorganic materials and the durability such as strength, salt resistance and freeze-thaw resistance are improved. If the content is more than 99% by weight, it is difficult and economical to further improve the strength and durability of inducing the bonding of inorganic materials.

The methyl methacrylate-butadiene serves to improve adhesion and toughness. It is preferable that the methyl methacrylate-butadiene is contained in the liquid binder in an amount of 0.1 to 40 wt%. If the content of methyl methacrylate-butadiene is less than 0.1 wt%, the effect of improving adhesion and toughness may be insignificant When the content of methyl methacrylate-butadiene exceeds 40% by weight, it is difficult and economical to further improve adhesion and toughness.

The urethane acrylic oligomer is used for improving the elasticity and durability of a concrete structure surface protecting composition. If the content of the urethane acrylic oligomer is more than 30% by weight, the performance of the composition for protecting the surface of the concrete structure may be improved but the workability and price competitiveness may be deteriorated. If the content of the urethane acryl oligomer is less than 0.1 wt%, the workability of the composition for protecting a concrete structure surface is improved, but the effect of improving elasticity and durability may be weak.

The polyvinyl acetate-vinyl versatate is used to prepare a composition for surface protection of concrete structures having ductility and adhesion. Preferably, the polyvinyl acetate-vinyl versatate is contained in the liquid binder in an amount of 0.1 to 20% by weight, and when the content of the polyvinyl acetate-vinyl versatate exceeds 20% by weight, If the content of the polyvinyl acetate-vinyl versatate is less than 0.1% by weight, the effect of improving the ductility and adhesive strength is weak and the embrittlement becomes strong, so that the impact strength may be lowered.

The polyvinyl propionate is used for improving the durability of a concrete structure surface protecting composition. The polyvinyl propionate is preferably contained in the liquid binder in an amount of 0.01 to 20% by weight. If the content of the polyvinyl propionate exceeds 20% by weight, workability and price competitiveness may be deteriorated. If the content of propionate is less than 0.01% by weight, the effect of improving durability is weak and the bonding force of the liquid binder may be lowered.

The fluororesin is used for strength improvement and prevention of contamination. The fluororesin is preferably contained in the liquid binder in an amount of 0.01 to 15 wt%. If the content of the fluororesin exceeds 15 wt%, the strength may be improved but the price competitiveness may be deteriorated. If the content of the fluororesin is 0.01 wt% %, The workability is improved but the strength improvement effect and the contamination prevention effect may be weak.

The liquid binder may further include 0.01 to 2% by weight of a polymerization inhibitor. The polymerization inhibitor may be used to prevent polymerization when the liquid phase binder is polymerized. Examples of the polymerization inhibitor include mono-tert-buthyl-hydroquinone, p-benzoquinone, tertiary butylcatechol, tolu-halidequinone, hydroquinone, hyroquinone, hydroquinone mono methyl ether, mono-tert-buthyl-hydroquinone or mixtures thereof. It is preferable that the polymerization inhibitor is contained in the liquid binder in an amount of 0.01 to 2% by weight. When the content of the polymerization inhibitor exceeds 2% by weight, the polymerization reaction may be deteriorated. When the content of the polymerization inhibitor is less than 0.01% The polymerization inhibiting effect may be weak.

The liquid binder may further contain 0.01 to 5% by weight of wax in order to suppress entanglement of the resin particles and promote the reaction. The wax may be used to block the air layer to promote the reaction of the liquid binder. The wax is preferably contained in the liquid binder in an amount of 0.01 to 5% by weight. When the content of the wax is more than 5% by weight, the reaction is accelerated and the pot life can be shortened. When the content of the wax is less than 0.01% Workability is good, but the effect of accelerating the reaction is weak and the curing may be delayed.

The liquid binder may further include 0.01 to 10 wt% of a smoothing agent for improving self-leveling property. The smoothing agent may be used to improve the fluidity and self-leveling property of the liquid phase binder. As the smoothing agent, a polycarboxylic acid-based smoothing agent may be used. When the content of the smoothing agent is more than 10 wt%, the reaction between the organic materials is delayed, the performance is not exerted, the material separation phenomenon easily occurs, If the content of the smoothing agent is less than 0.01% by weight, there is no material separation phenomenon, but the effect of improving the self-leveling property may be weak.

In addition, the liquid binder may further include 0.01 to 10% by weight of hydroxyethylcellulose for preventing separation of materials and improving workability. The hydroxyethylcellulose is used for preventing separation of the liquid-phase binding material and improving workability. The hydroxyethylcellulose is preferably contained in the liquid binder in an amount of 0.01 to 10 wt%. If the content of the hydroxyethylcellulose is less than 0.01% by weight, the material is likely to be separated. When the content of the hydroxyethylcellulose is more than 10% by weight, the material is not separated but the viscosity is increased, .

In addition, the liquid binder may further include a defoaming agent. The antifoaming agent is used to remove the air bubbles in the liquid binder to increase strength and durability. When the antifoaming agent is added to the liquid binder, air entraining effect can be imparted to improve workability and pot life. The defoaming agent is preferably contained in the liquid binder in an amount of 0.01 to 5% by weight. Examples of the defoaming agent include alcohol defoaming agents, silicone defoaming agents, fatty acid defoaming agents, oil defoaming agents, ester defoaming agents and oxyalkylene defoaming agents. Examples of the silicone defoaming agent include dimethyl silicone oil, polyorganosiloxane, and fluorosilicone oil. Examples of the fatty acid defoaming agent include stearic acid and oleic acid. Examples of the oil-based antifoaming agents include kerosene, animal and plant oil, and castor oil. Examples of the ester type antifoaming agents include solitol trioleate, glycerol monoricinolate, and the like. Examples of the oxyalkylene antifoaming agents include polyoxyalkylene, acetylene ethers, polyoxyalkylene diisocyanate esters, and polyoxyalkylene alkylamines. Examples of the alcohol-based defoaming agent include glycol.

Further, the liquid binder may further include a water reducing agent. The water reducing agent is used for improving the strength and durability by reducing the water-cement ratio and securing the fluidity of the liquid binder. When the water reducing agent is added to the liquid binder, the water-cement ratio is reduced. The water reducing agent is preferably contained in the liquid binder in an amount of 0.01 to 5% by weight. The water reducing agent may be a polycarbonate-based, melamine-based or naphthalene-based water reducing agent. However, the polycarboxylic acid-based and melamine-based compounds may lower the strength of the composition for protecting the concrete structure surface compared to the naphthalene- It is preferable to use a naphthalene-based water reducing agent which does not lower the strength, workability and pot life of the surface protective composition.

 The inorganic binder is used for improving flame retardancy, exhibiting long-term strength, improving durability, suppressing temperature rise, and improving abrasion resistance. The inorganic binder is used in an amount of 10 to 95 wt% %. When the content of the inorganic binder is more than 95% by weight, the flame retardancy is improved but the workability and strength may be lowered. If the content is less than 10% by weight, workability and strength are increased, May be weak.

The inorganic binder is usually 25 to 75 wt% of Portland cement, 5 to 30 wt% of hard calcium carbonate, 5 to 35 wt% of calcium aluminate, 0.1 to 15 wt% of magnesium oxide, 1 to 30 wt% of blast furnace slag, By weight of aluminum oxide, 0.01 to 20% by weight of aluminum powder, 0.01 to 10% by weight of bentonite, 0.1 to 15% by weight of titanium oxide and 10 to 63% by weight of silica silica.

The ordinary portland cement is preferably the one specified in KS, and the cement distributed in the general market can be used. The ordinary Portland cement is preferably contained in the inorganic binder in an amount of 25 to 75% by weight.

The hard calcium carbonate is used for obtaining a filling effect and a thickening effect of a composition for protecting a surface of a concrete structure. The content of the light calcium carbonate is preferably 5 to 30% by weight based on the inorganic binder. If the content of the hard calcium carbonate is less than 5% by weight, the filling effect and the thickening effect are insufficient. If the content of the hard calcium carbonate is 30% by weight or more, the workability may be deteriorated.

The calcium aluminate is an inorganic fastidious mineral material which is added to increase hydration reactivity and to suppress cracking. It reacts with water in an instant when it comes into contact with water to form an ettringite hydrate, So that excellent compressive strength can be obtained within a short time. The calcium aluminate is preferably contained in the inorganic binder in an amount of 5 to 35% by weight. If the calcium aluminate content is less than 5% by weight, the strength improving effect and the crack generation inhibiting effect may be insignificant. If the calcium aluminate content is less than 35% by weight %, The good physical properties can be obtained due to the quick hardening property, but the manufacturing cost is not high and it is not economical.

The magnesium oxide (MgO) is an inorganic flame-retardant material. The magnesium oxide has a formula MgO and a compounding amount of 40.3. The magnesium oxide is also called goto (industrial grade), the industrial product is called magnesia, and the medicine is called magnesia woaster. Magnesium oxide has a melting point of 2826 캜, a boiling point of 3600 캜, a specific gravity of 3.65, a cubic crystal system solubility of 0.62 mg / 100 g, and a refractive index of 1.7364. Magnesium oxide is obtained by heating metallic magnesium in air, and industrially, magnesium carbonate (magnesite), magnesium hydroxide carbonate, magnesium hydroxide and the like are calcined. Magnesium oxide is a white crystalline solid, chemically relatively inert. Magnesium oxide is only slightly soluble in water, but it dissolves in dilute acid. Magnesium oxide slowly absorbs water and carbon dioxide gas in the air and becomes magnesium hydroxide carbonate. Magnesium oxide is very reflective (visible) and near-ultraviolet (reflectivity) and is used as a reflector or white standard in optics. Magnesium oxide is industrially used as a raw material for magnesia cement, steelmaking furnace material and refractory brick tile. The magnesium oxide is preferably contained in the inorganic binder in an amount of 0.1 to 15% by weight. If the content of magnesium oxide is less than 0.1% by weight, workability and strength are increased but the flame retardant effect may be lowered. If the content of magnesium oxide exceeds 15% by weight, flame retardancy is improved but workability and strength may be lowered have.

The blast furnace slag is used for improving latent hydraulic characteristics, long-term strength development and durability. When the weight ratio of the blast furnace slag is increased, the early strength is lowered, but the long-term strength development and durability are increased. The blast furnace slag is preferably contained in the inorganic binder in an amount of 1 to 30% by weight.

The meta kaolin is used for potential hydraulic properties, long-term strength development and durability enhancement. When the weight ratio of meta kaolin is increased, the early strength is lowered, but the long-term strength development and durability are increased. The meta-kaolin is preferably contained in the inorganic binder in an amount of 0.1 to 20 wt%.

The aluminum powder is used to prevent drying shrinkage. The aluminum powder is preferably contained in the inorganic binder in an amount of 0.01 to 20% by weight. If the content of the aluminum powder is less than 0.01% by weight, the effect of suppressing the shrinkage by the cement may be weak. If the content of the aluminum powder exceeds 20% by weight, the workability may be deteriorated.

The bentonite is used as a hygroscopic agent to prevent material separation and control viscosity. The bentonite is preferably contained in the inorganic binder in an amount of 0.01 to 10 wt%. If the content of bentonite is less than 0.01 wt%, the workability is good but the effect of preventing material separation may be small. If the content of bentonite is more than 10 wt%, the material separation phenomenon does not occur but the viscosity is increased, have.

The above-mentioned titanium oxide is used for eliminating gloss of an acid-resistant / alkali-resistant paint, a white pigment having high hiding power, artificial dogs, staple fiber and chemical fiber and is harmless, It is used for packing paper of food. It is also used in soap, printing, printing ink, artificial leather, etc. in addition to polishing of metal products, raw materials for organic titanium compounds, enamel and ceramic glazes, titanium capacitors and dental materials. Titanium oxide (II), titanium oxide (III), titanium oxide (IV) and titanium peroxide are known as titanium oxide. In the present invention, titanium oxide (IV) is preferably used. Since titanium oxide has excellent light reflectivity in the infrared region, it exerts an excellent effect in suppressing the temperature rise of the road surface. The titanium oxide is preferably contained in the inorganic binder in an amount of 0.1 to 15% by weight, and when the content of the titanium oxide exceeds 15% by weight, the temperature rise inhibiting effect is excellent and the antifouling property is improved, If the content of the titanium oxide is less than 0.1% by weight, the effect of suppressing the temperature rise may be small.

The silica silica sand is used for improving the strength and abrasion resistance of the concrete structure surface protecting composition. It is preferable that the silica silica has a particle size of from 4 to 8 (0.05 to 2.5 mm). If it is larger than this, there is a fear of material separation of the composition for protecting the surface of the concrete structure. If it is smaller than that, It is possible to reduce the workability. It is preferable that the silica silica is contained in the inorganic binder in an amount of 10 to 63% by weight.

The inorganic binder may further include a retarder. The retarder is used for delaying rapid curing in order to ensure workability for a predetermined period of time, and it is preferable that the retarder is contained in the inorganic binder in an amount of 0.01 to 5 wt%. As the delaying agent, generally well known substances can be used. Examples thereof include saccharides such as glucose, glucose, texturin and dextran, acids or salts thereof such as gluconic acid, malic acid, citric acid and citric acid, Or a salt thereof, a phosphonic acid or a derivative thereof, and a polyhydric alcohol such as glycerin.

The present invention provides a concrete structure repair method using the above-described composition for protecting a concrete structure. Hereinafter, the concrete structure refers to a road surface, a bridge bridge, a concrete slab of a bridge, a bridge bottom, a function culvert portion, and the like, and includes all structures made of concrete.

The method for repairing concrete structures according to a preferred embodiment of the present invention includes steps of chipping and cleaning a concrete slab surface and impurities of a concrete slab surface by a planer, a short blaster, or a hand water jet, Applying a primer to improve the adhesion of the concrete slab and the concrete structure surface protecting composition, and applying the composition for surface protection of the concrete structure to the top of the applied primer. In this case, the cleaning step may include a step of using the vacuum suction vehicle to clean the area where the repair area is large.

The primer may include at least one material selected from the above-described liquid binders, styrene-butadiene, polyethylene vinyl acetate, and acrylic. The liquid binder used as the primer is a copolymer of 40 to 99% by weight of polystyrene-acrylate, 0.1 to 40% by weight of methyl methacrylate-butadiene for improving the adhesion and toughness, for improving the strength and durability, , 0.1 to 30% by weight of urethane acryl oligomer for improving elasticity and durability, 0.1 to 20% by weight of polyvinyl acetate-vinyl versatate for improving ductility and adhesion, polyvinyl propionate for improving durability of 0.01 to 20% By weight and 0.01 to 15% by weight of a fluororesin for improving the strength and preventing contamination.

Hereinafter, examples of the composition for protecting a surface of a concrete structure according to the present invention will be more specifically shown, and the present invention is not limited by the following embodiments.

≪ Example 1 >

40 wt% of an inorganic binder and 60 wt% of a liquid binder were stirred in a forced mixer for 2 minutes to prepare a composition for protecting the surface of a concrete structure.

The liquid binder was prepared by mixing 90 wt% of polystyrene-acrylate, 2 wt% of methyl methacrylate-butadiene, 2 wt% of urethane acryl oligomer, 1 wt% of polyvinylacetate-vinyl versatate, 1 wt% of polyvinyl propionate, 0.5% by weight of wax, 0.5% by weight of a smoothing agent, 0.5% by weight of hydroxyethylcellulose, 0.5% by weight of an antifoaming agent and 0.5% by weight of a water reducing agent were mixed and used. Mono-tert-butyl-hydroquinone was used as the polymerization inhibitor. The smoothing agent used was a polycarboxylic acid-based smoothing agent, the defoaming agent used was a silicone-based defoaming agent, and the reducing agent used was a naphthalene-based reducing agent.

The inorganic binder is usually 20 wt% of Portland cement, 5 wt% of hard calcium carbonate, 15 wt% of calcium aluminate, 5 wt% of magnesium oxide, 10 wt% of blast furnace slag, 10 wt% of meta kaolin, 5% by weight of titanium oxide, 4.5% by weight of titanium oxide, 20% by weight of silica silica, and retarder 0.5 were mixed and used. Citric acid was used as the retarder.

≪ Example 2 >

40 wt% of an inorganic binder and 60 wt% of a liquid binder were stirred in a forced mixer for 2 minutes to prepare a composition for protecting the surface of a concrete structure.

The liquid binder was prepared by mixing 80 wt% of polystyrene-acrylate, 4 wt% of methyl methacrylate-butadiene, 4 wt% of urethane acryl oligomer, 3 wt% of polyvinylacetate-vinyl versatate, 3 wt% of polyvinyl propionate, 3% by weight of a resin, 0.5% by weight of a polymerization inhibitor, 0.5% by weight of wax, 0.5% by weight of a smoothing agent, 0.5% by weight of hydroxyethylcellulose, 0.5% by weight of an antifoamer and 0.5% Mono-tert-butyl-hydroquinone was used as the polymerization inhibitor. The smoothing agent used was a polycarboxylic acid-based smoothing agent, the defoaming agent used was a silicone-based defoaming agent, and the reducing agent used was a naphthalene-based reducing agent.

The inorganic binder is usually 20 wt% of Portland cement, 5 wt% of hard calcium carbonate, 15 wt% of calcium aluminate, 5 wt% of magnesium oxide, 10 wt% of blast furnace slag, 10 wt% of meta kaolin, 5% by weight of titanium oxide, 4.5% by weight of titanium oxide, 20% by weight of silica silica, and retarder 0.5 were mixed and used. Citric acid was used as the retarder.

≪ Example 3 >

40 wt% of an inorganic binder and 60 wt% of a liquid binder were stirred in a forced mixer for 2 minutes to prepare a composition for protecting the surface of a concrete structure.

The liquid binder was prepared by mixing 70 wt% of polystyrene-acrylate, 6 wt% of methyl methacrylate-butadiene, 6 wt% of urethane acryl oligomer, 5 wt% of polyvinyl acetate-vinyl versatate, 5 wt% of polyvinyl propionate, 5% by weight of a resin, 0.5% by weight of a polymerization inhibitor, 0.5% by weight of wax, 0.5% by weight of a smoothing agent, 0.5% by weight of hydroxyethylcellulose, 0.5% by weight of an antifoaming agent and 0.5% by weight of a water reducing agent. Mono-tert-butyl-hydroquinone was used as the polymerization inhibitor. The smoothing agent used was a polycarboxylic acid-based smoothing agent, the defoaming agent used was a silicone-based defoaming agent, and the reducing agent used was a naphthalene-based reducing agent.

The inorganic binder is usually 20 wt% of Portland cement, 5 wt% of hard calcium carbonate, 15 wt% of calcium aluminate, 5 wt% of magnesium oxide, 10 wt% of blast furnace slag, 10 wt% of meta kaolin, 5% by weight of titanium oxide, 4.5% by weight of titanium oxide, 20% by weight of silica silica, and retarder 0.5 were mixed and used. Citric acid was used as the retarder.

A comparative example which can be compared with the embodiments of the present invention is shown in order to more easily grasp the characteristics of the above-described first to third embodiments. It is to be noted that Comparative Example 1 described below is provided merely for comparison with the characteristics of the embodiments, and is not a prior art of the present invention.

≪ Comparative Example 1 &

40% by weight of Portland cement and 60% by weight of polystyrene-acrylate were mixed and stirred in a continuous mixer for 2 minutes to prepare a composition.

The following test examples show experimental results comparing characteristics of the embodiment of the present invention and the characteristics of the first comparative example so that the characteristics of the first to third embodiments of the present invention can be grasped more easily.

≪ Test Example 1 >

Slump-flow test (degree of kneading) was carried out according to the method defined in KS F 2402 for the composition for protecting the surface of a concrete structure prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1. The slump-flow test tests the dough of the composition such as the flue and viscosity of the composition. The larger the value, the better the workability, that is, the workability at the time of casting the composition.

Table 1 below shows the change in slump-flow over time.

division
Slump-flow (cm) Example 1 53 Example 2 64 Example 3 66 Comparative Example 1 51

As shown in Table 1 above, it can be seen that the composition for surface protection of concrete structures prepared according to Examples 1 to 3 is superior in workability to the composition prepared according to Comparative Example 1.

≪ Test Example 2 &

Compressive strength tests were conducted according to the methods of the surface protective composition for concrete structures prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 according to the method specified in KS F 2477 (Method for testing strength of polymer-cement mortar) .

Table 2 below shows the change in compressive strength with time.

division
Compressive strength (kgf / ㎠) After 3 hours After 1 day After 7 days Example 1 130 276 348 Example 2 140 285 362 Example 3 150 296 388 Comparative Example 1 112 252 323

As shown in Table 2 above, the compositions for surface protection of concrete structures prepared according to Examples 1 to 3 had significantly higher compressive strength than the composition prepared according to Comparative Example 1. [

≪ Test Example 3 >

The flexural strengths of the concrete structure surface protection composition prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 were measured according to the method specified in KS F 2477 (strength test method of polymer-cement mortar).

Table 3 below shows the changes in flexural strength with time.

division
Bending strength (kgf / ㎠) After 3 hours After 1 day After 7 days Example 1 45 52 76 Example 2 55 68 85 Example 3 61 76 92 Comparative Example 1 40 48 68

As shown in Table 3 above, the composition for surface protection of concrete structures prepared according to Examples 1 to 3 had significantly higher bending strength than the composition prepared according to Comparative Example 1. [

<Test Example 4>

The adhesive strength of the concrete structure surface protecting composition prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 were measured by JIS A 6916 (Wall coatings for thick textured finishes) The results are shown in Table 4 below.

division
Adhesion strength (kgf / cm 2) After 3 hours After 1 day After 7 days Example 1 20.0 20.6 21.0 Example 2 20.4 21.3 22.6 Example 3 21.0 22.3 23.5 Comparative Example 1 19.4 19.8 20.8

As shown in Table 4 above, it was confirmed that the composition for surface protection of concrete structures prepared according to Examples 1 to 3 had much better adhesive strength than the composition prepared according to Comparative Example 1. [

&Lt; Test Example 5 >

Table 5 shows the results of measurement of the water absorption ratio according to the method of preparing the composition for surface protection of concrete structures prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 in KS F 4916 (polymer for cement admixture) .

division Example 1 Example 2 Example 3 Comparative Example 1 Absorption Rate (%) 0.10 0.08 0.06 0.13

As shown in Table 5 above, the water absorbing ratio of the concrete structure surface protecting composition prepared according to Examples 1 to 3 was lower than that of the composition prepared according to Comparative Example 1.

&Lt; Test Example 6 >

The penetration depth test of the chloride ion was performed on the surface protection composition of concrete structures prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 by JIS A 1171 (Test Method of Polymer Cement Mortar) The results are shown in Table 6.

division Example 1 Example 2 Example 3 Comparative Example 1 Chloride ion penetration depth (mm) 0.2 0.13 0.08 0.35

As shown in Table 6 above, the composition for protecting the surface of concrete structures prepared according to Examples 1 to 3 had a lower chloride ion penetration depth than the composition prepared according to Comparative Example 1, .

&Lt; Test Example 7 >

The composition for surface protection of concrete structures prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 were subjected to a freeze-thaw resistance test according to the method defined in KS F 2456. Freezing and thawing means that the water absorbed in the concrete is frozen and melted. When freezing and thawing is repeated, fine cracks are generated in the concrete structure, and the durability is lowered.

Table 7 shows the durability indexes of the respective examples and the comparative example 1 according to the freeze-thaw resistance test.

division Example 1 Example 2 Example 3 Comparative Example 1 Durability index 94 95 96 92

As shown in Table 7 above, the durability of the concrete structure surface protecting composition prepared according to Examples 1 to 3 is much higher than that of the composition prepared according to Comparative Example 1, because the durability index is much higher.

<Test Example 8>

The composition for surface protection of concrete structures prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 were tested in accordance with JIS A 1171 (Test Method for Polymer Cement Mortar) Respectively.

division Example 1 Example 2 Example 3 Comparative Example 1 Neutralization depth (mm) 0.2 0.1 0 0.5

As shown in Table 8, it was confirmed that the composition for protecting the surface of the concrete structure prepared according to Examples 1 to 3 had a lower neutralization penetration depth than the composition prepared according to Comparative Example 1, and thus was highly resistant to neutralization there was.

&Lt; Test Example 9 >

The composition for surface protection of concrete structures prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 were dissolved in 2% hydrochloric acid and 5% hydrochloric acid according to the Japanese Industrial Standards (original test method for chemical resistance test by solution immersion of concrete) Sulfuric acid and 45% sodium hydroxide were immersed in the test solution for 28 days, and the results of the chemical resistance test are shown in Table 9 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Weight change rate
(%) Hydrochloric acid -1.0 -0.8 -0.6 -2.0 Sulfuric acid -0.1 - 0.1 -0.5 Sodium hydroxide +0.7 +1.3 +1.8 +0.5

As shown in Table 9, the composition for surface protection of concrete structures prepared according to Examples 1 to 3 exhibited less weight change rate with respect to chemical resistance than the composition prepared according to Comparative Example 1, and showed resistance to chemical resistance High.

&Lt; Test Example 10 &

The shrinkage ratio of the concrete structure prepared according to Examples 1 to 3 and the composition prepared according to Comparative Example 1 were measured by KS F 2424 (method for changing the length of concrete) 10.

division Example 1 Example 2 Example 3 Comparative Example 1 Dry shrinkage (%) 0.06 0.03 0.03 0.18

As shown in Table 10, it was confirmed that the composition for protecting the concrete structure according to Examples 1 to 3 had shrinkage reduction effect by reducing the amount of drying shrinkage as compared with the composition prepared according to Comparative Example 1. [

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, This is possible.

Claims (9)

5 to 90% by weight of a liquid binder and 10 to 95% by weight of an inorganic binder,
Wherein the liquid-phase binder comprises 40 to 99 wt% of polystyrene-acrylate, 0.1 to 40 wt% of methyl methacrylate-butadiene, 0.1 to 30 wt% of urethane acryl oligomer, 0.1 to 20 wt% of polyvinyl acetate- 0.01 to 20% by weight of propionate and 0.01 to 15% by weight of a fluororesin,
The inorganic binder is usually 25 to 75 wt% of Portland cement, 5 to 30 wt% of hard calcium carbonate, 5 to 35 wt% of calcium aluminate, 0.1 to 15 wt% of magnesium oxide, 1 to 30 wt% of blast furnace slag, By weight of aluminum oxide, 0.01 to 20% by weight of aluminum powder, 0.01 to 10% by weight of bentonite, 0.1 to 15% by weight of titanium oxide, and 10 to 63% by weight of silica silica silica.
3. The composition of claim 1, wherein the liquid binder is selected from the group consisting of mono-tert-butyl-hydroquinone, p-benzoquinone, tertiary butyl catechol, tolu- - hydroquinone in an amount of 0.01 to 2% by weight based on the total weight of the composition.
The concrete surface protection composition according to claim 1, wherein the liquid binder further comprises 0.01 to 5% by weight of wax.
The concrete surface protection composition according to claim 1, wherein the liquid binder further comprises 0.01 to 10 wt% of a smoothing agent for improving self-leveling property.
The concrete surface protecting composition according to claim 1, wherein the liquid binder further comprises 0.01 to 10% by weight of hydroxyethylcellulose.
delete The concrete surface protection composition according to claim 1, wherein the inorganic binder further comprises 0.01 to 5% by weight of a retarder for delaying rapid curing to ensure workability.
Removing and cleaning the laitance and impurities of the concrete slab surface by chipping by a planer, a short blaster, or a hand water jet;
Applying a primer to improve adhesion of the concrete slab and the concrete structure surface protecting composition after confirming the moisture content of the cleaned area; And
The method for repairing a concrete structure according to claim 1, further comprising the step of applying the composition for surface protection of a concrete structure as set forth in claim 1 to an upper part to which said primer is applied.
The concrete structure repairing method according to claim 8, wherein the primer comprises at least one material selected from the group consisting of the liquid binder according to claim 1, styrene-butadiene, polyethylene vinyl acetate and acrylic.