KR101422206B1 - High-performance flowing cement mortar composition and surface protection method of concrete structures using the composite - Google Patents

Abstract

The present invention relates to a cement mortar composition comprising 10 to 60 wt% of rapidly-hardening binder, 10 to 60 wt% of fine aggregate, 0.01 to 30 wt% of polymer admixture and 0.1 to 30 wt% of water, wherein the polymer admixture comprises 75 to 99 wt% of methyl methacrylate-styrene, 0.1 to 10 wt% of methyl methacrylate-butadiene, 0.1 to 10 wt% of butylacrylate-styrene, 0.1 to 10 wt% of acrylonitrile and 0.01 to 5 wt% of vinyl acetate; and a surface protection method of a concrete structure. According to the present invention, the service period of a concrete structure can be increased, operation and maintenance costs thereof can be reduced, and constructability thereof can be improved as construction is facilitated by excellent strength, durability, and flowability, construction period is reduced by rapidly hardening, construction costs can be reduced, repairing period can be reduced, and field applicability, workability, pavement waterproofing layer protection, chloride penetration resistance, durability and adhesion and water resistance are excellent.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-performance flowable cement mortar composition and a surface protection method for a concrete structure using the same,

The present invention relates to a high-performance fluidity cement mortar composition and a surface protection method for a concrete structure using the same. More particularly, the present invention relates to a high-performance fluidity cement mortar composition which is excellent in strength, durability and fluidity and can be easily applied, It is possible to shorten the period of saving and repairing, and it is possible to increase the public period of concrete structure, reduce maintenance cost, and improve workability by being excellent in field applicability, workability, chloride penetration resistance, protection of waterproof layer of bridges, durability, And a method for protecting a surface of a concrete structure using the mortar composition.

Concrete pavement is rigid, has a large construction restriction on temperature and surrounding environment, takes a long period of curing, has cracks due to drying shrinkage, has unfavorable riding comfort and comfort but has excellent durability and reduced maintenance cost And some of them are applied to highway and medium-sized roads. In recent emergency repair work, polymer cement concrete with polymer emulsion added to concrete has been increasingly used to overcome the disadvantages of crude steel portland cement.

In general, polymer cement mortar is widely used for maintenance and reinforcement of areas where corrosion, erosion, etc. of the bottom plate of a bridge, the road surface and the lower part of a bridge occur frequently. The hardened Portland cement has the advantages of quick curing time and early strength development compared with portland cement. However, the penetration of chlorides and moisture causes the concrete to be corroded.

Generally, there is a disadvantage in that when the concrete structure is manufactured or packaged, cracks are generated due to drying shrinkage, and the surface of the concrete structure is subjected to levitation due to bleeding, resulting in weak surface strength and durability.

1. Domestic Registered Patent No. 10-1302448 (Polymer cement mortar composition having excellent flowability and initial strength development and road maintenance method using the same) 2. Domestic registered patent No. 10-1311331 (fluid refractory mixture)

The problems to be solved by the present invention are that it is easy to construct due to excellent strength, durability and fluidity, and it can be cured within a short time, shortening the construction period, reducing the construction cost and shortening the repair period, The present invention relates to a high-performance fluidity cement mortar composition capable of increasing the durability, adhesion and waterproofing properties of a concrete structure, reducing maintenance costs, and improving workability, and a surface protection method for a concrete structure using the same .

In order to achieve the above object, the present invention provides a method for producing a polymer composite material, which comprises 10 to 60 wt% of a quick hard binder, 10 to 60 wt% of a fine aggregate, 0.01 to 30 wt% of a polymer admixture and 0.1 to 30 wt% By weight of methyl methacrylate-styrene, 0.1 to 10% by weight of methyl methacrylate-butadiene, 0.1 to 10% by weight of butyl acrylate-styrene, 0.1 to 10% by weight of acrylonitrile and 0.01 to 5% by weight of vinyl acetate % Of the cement mortar composition.

The polymer admixture may further comprise 0.001 to 3% by weight of at least one material selected from polyethylene oxide, urethane and polycarboxylic acid to improve self-leveling.

The polymer admixture may further contain 0.001 to 5% by weight of at least one material selected from the group consisting of polyvinyl methyl ether, polyvinyl alcohol and polyvinyl amine.

The polymer admixture may further contain 0.001 to 5% by weight of a polypropylene emulsion to improve water resistance and abrasion resistance.

The quick-setting binder is usually 20 to 90 wt% of Portland cement, 5 to 50 wt% of calcium or magnesium sulfoaluminate, 0.1 to 20 wt% of alumina cement, 0.1 to 20 wt% of calcium aluminate, 0.1 to 20 wt% 0.1 to 20% by weight of zeolite, 0.1 to 10% by weight of gypsum and 0.01 to 5% by weight of aluminum powder.

The quick-setting binder may further comprise 0.001 to 5% by weight of at least one material selected from the group consisting of polycarboxylic acids, naphthalene, melamine and lignin.

The quick-setting binder may further contain 0.001 to 6% by weight of at least one material selected from methylcellulose, starch and gum.

The quick-setting binder may further comprise 0.01 to 10% by weight of sodium kosane.

Also, the quick-setting binder may further include 0.01 to 5% by weight of reinforcing fibers. It is preferable that the reinforcing fiber is made of at least one material selected from nylon fiber, polyethylene, polypropylene, glass fiber and carbon fiber.

The quick-setting binder may further contain 0.1 to 10% by weight of aluminum sulfate.

The present invention relates to a method for manufacturing a chipped structure, comprising the steps of: chipping a portion of a concrete structure on which surface delamination due to scaling, aggregate dropout, micro-cracking due to plastic cracking has occurred, cleaning the impurities or slurry of the chipped portion, Applying a primer to the surface of the primer, and curing the cement mortar composition by curing the top of the primer on the primer-coated surface.

According to the present invention, there is also provided a method of manufacturing a concrete structure, comprising the steps of: removing laying matter or impurities on a surface of a concrete structure; applying a primer to a site where the laying or impurities have been removed; And curing and curing the above-mentioned cement mortar composition on the surface of the concrete structure.

According to the high-performance fluidity cement mortar composition of the present invention, since it is excellent in field applicability, workability, chloride penetration resistance, cross-linked waterproof layer protection, durability, adhesion property and waterproof property, it is possible to increase the durability of concrete structure, Can be implemented.

Further, the cement mortar composition of the present invention is excellent in strength, durability and fluidity, so that it is easy to construct and harden in a short time, shortening the construction period, reducing the construction cost and shortening the maintenance period.

According to the surface protection method of a concrete structure using the cement mortar composition of the present invention, a cement mortar composition having excellent flowability and workability is fast-curing and has high strength and durability, thereby shortening the construction period and increasing the period of use of the concrete structure In addition, it can reduce the cost of maintenance, and it has excellent strength characteristics and durability, which can reduce the maintenance cost and increase the maintenance period.

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.

Hereinafter, the concrete structure includes not only ordinary roads and expressways but also all the structures made of concrete including a bridge for vehicles, a concrete slab for bridges, a road surface, a bridge bottom, a sewer pipe, an underground structure, It is used as meaning.

The cement mortar composition excellent in strength, durability, flowability and workability according to a preferred embodiment of the present invention includes a quick-setting binder, a fine aggregate, a polymer admixture and water. The cement mortar composition preferably contains 10 to 60 wt% of a quick-setting binder, 10 to 60 wt% of a fine aggregate, 0.01 to 30 wt% of a polymer admixture, and 0.1 to 30 wt% of water.

The fine aggregate is preferably contained in the cement mortar composition in an amount of 10 to 60% by weight. Aggregates are classified into fine aggregate and coarse aggregate. Hereinafter, those having a grain size of 5 mm or less are called fine aggregate. The fine aggregate is preferably a mixture of silica No. 6 and silica No. 7 at a weight ratio of 0.05 to 0.4: 0.6: 0.95.

The quick-setting binder is preferably contained in the cement mortar composition in an amount of 10 to 60% by weight. The quick-setting binder usually comprises Portland cement, calcium or magnesium sulfoaluminate, alumina cement, calcium aluminate, kaolinite, zeolite, gypsum and aluminum powder. The quick-setting binder is usually 20 to 90 wt% of Portland cement, 5 to 50 wt% of calcium or magnesium sulfoaluminate, 0.1 to 20 wt% of alumina cement, 0.1 to 20 wt% of calcium aluminate, 0.1 to 20 wt% 0.1 to 20% by weight of zeolite, 0.1 to 10% by weight of gypsum and 0.01 to 5% by weight of aluminum powder.

The ordinary Portland cement is preferably those specified in KS, and ordinary Portland cement distributed in the market can be used. It is preferable that the ordinary Portland cement contains 20 to 90% by weight of the quick-setting binder.

The calcium or magnesium sulfoaluminate is an inorganic-based ultra-rapid-speed material. When it comes into contact with water, the calcium or magnesium sulfoaluminate reacts with water in an instant to generate an ettringite hydrate. Thus, And the compressive strength of the cement can be obtained within a few hours. The calcium or magnesium sulfoaluminate preferably contains 5 to 50% by weight of the quick-setting binder. When the content of the magnesium sulfoaluminate is less than 5% by weight, it is difficult to expect a sufficient initial strength development. When the content of the magnesium sulfoaluminate exceeds 50% by weight, the strength and the development are excellent.

The alumina cement is an inorganic-based ultra-rapid-speed cement material, and when mixed with cement, the compressive strength of ordinary portland cement obtained in several days or several days can be obtained within a few hours. The alumina cement is preferably contained in the quick-setting binder in an amount of 0.1 to 20% by weight. If the content of the alumina cement is less than 0.1% by weight, initial strength development and durability performance may be weak. If the content is more than 20% by weight, workability and price competitiveness may be deteriorated.

The calcium aluminate is mixed with gypsum and reacted when mixed with water to form etalinite, which is used to be swellable when mixed with cement to prevent drying shrinkage. The calcium aluminate preferably contains 0.1 to 20% by weight of the quick-setting binder. If the content of calcium aluminate is less than 0.1% by weight, it is difficult to expect sufficient initial strength development and shrinkage reduction effect. If the content of calcium aluminate exceeds 20% by weight, shrinkage reduction effect is excellent but workability may be deteriorated.

The above-mentioned kaolinite clay is a latent hydraulic inorganic fine powder which improves the long-term strength of the cement hardened body and tightens the hydrated structure of the hardened cement body to increase the chemical resistance and durability. It is preferable that the kite clay is contained in the quick-setting binder in an amount of 0.1 to 20% by weight. When the content of the kaolinic clay is less than 0.1% by weight, the effect of improving the long-term strength and improving the durability is insufficient. When the content is more than 20% by weight, the initial strength development may be delayed.

Zeolite is used to inhibit strength enhancement and alkali aggregate reaction. The zeolite is preferably contained in the quick-setting binder in an amount of 0.1 to 20% by weight. If the content of the zeolite is less than 0.1 wt%, the strength enhancement and the inhibition effect of the alkali aggregate reaction may be weak. If the content is more than 20 wt%, the initial strength development may be delayed and the workability may be deteriorated.

The gypsum is used for initial strength development. The gypsum may be an anhydrous gypsum or an alumite. When the content of the gypsum is increased, rapid curing characteristics are exhibited. The gypsum is preferably contained in the quick-setting binder in an amount of 0.1 to 10% by weight. If the content of the gypsum is less than 0.1% by weight, the initial strength development effect may be insufficient. If the content is more than 10% by weight, workability and water resistance may be deteriorated.

The aluminum powder serves to inhibit shrinkage by cement. The aluminum powder is preferably contained in an amount of 0.01 to 5% by weight in the quick-setting binder. If the content of the aluminum powder is less than 0.01% by weight, the effect of suppressing the shrinkage due to cement may be weak. If the content of aluminum powder exceeds 5% by weight, the workability may be deteriorated.

The quick-setting binder may further comprise soda soda. Said potassium soda is used to improve the water resistance of the composition.

The quick-setting binder may further comprise reinforcing fibers. The reinforcing fiber is used to prevent flexural strength, tensile strength, and initial plastic cracking of the composition. The reinforcing fiber preferably has a length (L) to diameter (Diameter) ratio (L / D) of 20 to 200. It is preferable that the reinforcing fiber is contained in the fast-bonding material in an amount of 0.01 to 3% by weight. If the content of the reinforcing fibers is less than 0.01% by weight, the effect of improving the strength and the effect of preventing plastic cracking may be insufficient. If the content is more than 3% by weight, workability and water resistance may be deteriorated. The reinforcing fiber is preferably made of one or more materials selected from nylon, polyethylene, polypropylene, glass fiber and carbon fiber.

The quick-setting binder may further comprise at least one material selected from polycarbonic acid, naphthalene, melamine and lignin. The at least one material selected from the group consisting of polycarbonic acid, naphthalene, melamine and lignin makes the internal structure of the cement hardened to improve watertightness and freeze-thaw resistance and enhance durability. It also facilitates penetration into voids by adding both viscous and fluidic properties to unsettled cement mortar. It is preferable that at least one material selected from the above polycarboxylic acids, naphthalene, melamine and lignin is contained in the quick-setting binder in an amount of 0.001 to 5% by weight.

The quick-setting binder may further comprise at least one material selected from methylcellulose, starch and gum. The at least one material selected from the group consisting of methylcellulose, starch and gum is used for the purpose of preventing the separation of the cement mortar composition from the material and improving workability, and the material containing 0.001 to 6% by weight of the quick- desirable.

The quick-setting binder may further include a water reducing agent. The water reducing agent can be used to improve the strength and durability by reducing the water-cement ratio of the cement mortar composition. Examples of the water reducing agent include a polycarboxylic acid type, a melamine type, and a naphthalene type. The melamine type or naphthalene type water reducing agent is less effective for improving the strength and durability than the polycarboxylic acid type water reducing agent, and the water- , And the compatibility with the polymer admixture is poor. Therefore, it is preferable to use a polycarboxylic acid-based water reducing agent in the cement mortar composition of the present invention. The water reducing agent is preferably contained in the fast-bonding material in an amount of 0.01 to 5% by weight.

The quick-setting binder may further comprise a coagulation modifier. The coagulation controlling agent is used for delaying rapid curing in order to secure workability for a certain period of time, and it is preferable that the coagulating agent is contained in 0.001 to 4% by weight of the quick-setting binder. As the condensation regulator, generally well-known substances can be used. Examples thereof include sugars 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 quick-setting binder may further comprise a reaction initiator. The reaction initiator is used for improving the reactivity and improving the initial strength development effect. The reaction initiator is preferably contained in an amount of 0.01 to 10% by weight based on the quick-setting binder.

The polymer admixture is dispersed in a cement mortar cured body to form a film in the cured mortar cured body to improve warpage, tensile and adhesion strength and improve water retention to improve durability such as neutralization, chloride ion penetration, freezing and thawing, Self-leveling (self-leveling), and is preferably contained in the cement mortar composition in an amount of 0.1 to 30% by weight.

The polymer admixture includes methyl methacrylate-styrene, methyl methacrylate-butadiene, polyvinyl acetate ethylene resin, acrylonitrile, and vinyl acetate. Wherein the polymer admixture comprises 75 to 99% by weight of methyl methacrylate-styrene, 0.1 to 10% by weight of methyl methacrylate-butadiene, 0.1 to 10% by weight of butyl acrylate-styrene, 0.1 to 10% by weight of acrylonitrile, 0.01 to 5% by weight.

The methyl methacrylate-styrene not only improves warpage, tensile and adhesion strength by forming a polymer film inside the cement mortar composition, but also improves durability due to the polymer film. The methyl methacrylate-styrene is preferably contained in the polymer admixture in an amount of from 75 to 99% by weight. If the content of methyl methacrylate-styrene is less than 75% by weight, the effect of improving strength and durability may be insignificant. If the content of methyl methacrylate-styrene is more than 99% by weight,

The methyl methacrylate-butadiene is used for improving ductility and dispersibility. The methyl methacrylate-butadiene is preferably contained in the polymer admixture in an amount of 0.1 to 10% by weight. If the content of methylmethacrylate-butadiene is less than 0.1% by weight, the effect of improving ductility and dispersibility may be insignificant. If the content of methylmethacrylate-butadiene is more than 10% by weight, the ductility may be improved.

The butyl acrylate-styrene has excellent adhesion strength after being cured and enhances the strength of the cement to prevent detachment after adhesion. The butyl acrylate-styrene is preferably contained in the polymer admixture in an amount of 0.1 to 10% by weight. When the content of butyl acrylate-styrene is less than 0.1% by weight, the effect of improving the bonding strength may be weak. When the content of butyl acrylate-styrene is more than 10% by weight, workability may be lowered.

The acrylonitrile is used to improve the strength and durability of the cement mortar composition. The polyacrylonitrile is preferably contained in the polymer admixture in an amount of 0.1 to 10% by weight. If the content of acrylonitrile is less than 0.1% by weight, the effect of improving the strength and durability is insufficient. If the content is more than 10% by weight, the viscosity is lowered and the material separation phenomenon tends to occur.

The above-mentioned vinyl acetate is used for improving the surface hardness and the water resistance. The vinyl acetate is preferably contained in the polymer admixture in an amount of 0.01 to 5% by weight. If the content of the vinyl acetate is less than 0.1% by weight, the effect of improving the surface hardness and the water resistance is insufficient. If the content is more than 5% by weight, the viscosity may be increased and the workability may be lowered.

The polymer admixture may further comprise at least one substance selected from the group consisting of polyethylene oxide, urethane and polycarboxylic acid to improve self-leveling, and at least one substance selected from the group consisting of polyethylene oxide, urethane and polycarboxylic acid, By weight to 0.001% by weight to 3% by weight.

The polymer admixture may further contain 0.001 to 5% by weight of at least one material selected from the group consisting of polyvinyl methyl ether, polyvinyl alcohol and polyvinyl amine.

The polymer admixture may further contain 0.001 to 5% by weight of a polypropylene emulsion to improve water resistance and abrasion resistance.

The polymer admixture may further contain an antifoaming agent, and the antifoaming agent may be contained in the polymer admixture in an amount of 0.01 to 5 wt%. The antifoaming agent may be selected from polyether, silicone, ethyl alcohol and ethylene glycol And may be made of one or more materials.

The cement mortar composition according to a preferred embodiment of the present invention can be prepared by mixing a polymer admixture, a quick hardening binder, a fine aggregate and water, wherein the quick hardening binder is contained in the cement mortar composition in an amount of 10 to 60 wt% The fine aggregate is contained in the cement mortar composition in an amount of 10 to 60 wt%, the polymer admixture is contained in the cement mortar composition in an amount of 0.01 to 30 wt%, and the water is contained in the cement mortar composition in an amount of 0.1 to 30 wt% .

The surface protection method of a concrete structure using a cement mortar composition according to a preferred embodiment of the present invention is characterized in that a portion where fine cracks due to surface separation, aggregate dislocation, plastic cracking by scaling are generated on a concrete structure, , Cleaning the impurities, slurry or the like of the chipped portion with a hand water jet, a vacuum cleaner, etc., applying a primer to the chipped portion, and applying the primer onto the primed portion, And a step of curing and curing.

The method for protecting a surface of a concrete structure using a cement mortar composition according to a preferred embodiment of the present invention includes the steps of removing a laitance or an impurity on a surface of a concrete structure and a step of applying a primer to a site where laitance or impurities are removed And curing the cement mortar composition on top of the primer applied to increase the compatibility of the concrete structure.

Hereinafter, embodiments of the cement mortar composition excellent in strength, durability, fluidity, and workability according to the present invention will be more specifically shown and the present invention is not limited by the following embodiments.

35% by weight of a quick-setting binder and 35% by weight of a fine aggregate were added to a forced mixer and stirred. 20% by weight of the polymer admixture and 10% by weight of water were further mixed and stirred for 2 minutes to prepare a cement mortar composition.

At this time, the quick-setting binder is composed of 40 wt% of ordinary portland cement, 20 wt% of magnesium sulfoaluminate, 15 wt% of alumina cement, 6 wt% of calcium aluminate, 6 wt% of kaolinite, 6 wt% of zeolite, 0.5 wt% of aluminum powder, 0.5 wt% of a coagulation controlling agent, 0.5 wt% of polycarboxylic acid, and 0.5 wt% of starch were mixed and used. Citric acid was used as the coagulation control agent.

The polymer admixture was composed of 95% by weight of methyl methacrylate-styrene, 1% by weight of methyl methacrylate-butadiene, 1% by weight of butyl acrylate-styrene, 1% by weight of acrylonitrile, 1% % And 0.5% by weight of polyethylene oxide for improving self-leveling were mixed and used.

35% by weight of a quick-setting binder and 35% by weight of a fine aggregate were charged into a forced mixer and stirred. 10% by weight of the polymer admixture and 10% by weight of water were further mixed and stirred for 2 minutes to prepare a cement mortar composition.

At this time, the quick-setting binder is composed of 40 wt% of ordinary portland cement, 20 wt% of magnesium sulfoaluminate, 15 wt% of alumina cement, 6 wt% of calcium aluminate, 6 wt% of kaolinite, 6 wt% of zeolite, 0.5 wt% of aluminum powder, 0.5 wt% of a coagulation controlling agent, 0.5 wt% of polycarboxylic acid, and 0.5 wt% of starch were mixed and used. Citric acid was used as the coagulation control agent.

The polymer admixture was composed of 90 wt% of methyl methacrylate-styrene, 3 wt% of methyl methacrylate-butadiene, 2 wt% of butyl acrylate-styrene, 2 wt% of acrylonitrile, 2 wt% of vinyl acetate, 0.5 wt % And 0.5% by weight of polyethylene oxide for improving self-leveling were mixed and used.

35% by weight of a quick-setting binder and 35% by weight of a fine aggregate were added to a forced mixer and stirred. 20% by weight of the polymer admixture and 10% by weight of water were further mixed and stirred for 2 minutes to prepare a cement mortar composition.

At this time, the quick-setting binder is composed of 40 wt% of ordinary portland cement, 20 wt% of magnesium sulfoaluminate, 15 wt% of alumina cement, 6 wt% of calcium aluminate, 6 wt% of kaolinite, 6 wt% of zeolite, 0.5 wt% of aluminum powder, 0.5 wt% of a coagulation controlling agent, 0.5 wt% of polycarboxylic acid, and 0.5 wt% of starch were mixed and used. Citric acid was used as the coagulation control agent.

The polymer admixture was composed of 85 wt% methyl methacrylate-styrene, 5 wt% methyl methacrylate-butadiene, 3 wt% butyl acrylate-styrene, 3 wt% acrylonitrile, 3 wt% vinyl acetate, 0.5 wt% % And 0.5% by weight of polyethylene oxide for improving self-leveling were mixed and used.

Comparative Example 1 and Comparative Example 2 are shown for comparison with the physical properties of the cement mortar composition prepared according to Examples 1 to 3 above.

[Comparative Example 1]

35 wt% of ordinary Portland cement and 35 wt% of fine aggregate were added to a forced mixer and stirred. Further, 29 wt% of water was further mixed and stirred for 2 minutes. 1 wt% of polycarboxylic acid was added to prepare a cement mortar composition .

[Comparative Example 2]

35 wt% of cement and water and 35 wt% of fine aggregate were added to a forced mixer and stirred. 20 wt% of methyl methacrylate-styrene and 10 wt% of water were further mixed and stirred for 2 minutes to prepare a polymer cement mortar composition Respectively.

≪ Test Example 1 > Preparation of test specimens

A cement mortar composition was prepared by KS F 2476 (a method of making polymer cement mortar in a laboratory) according to the formulations presented in Examples 1 to 3 and Comparative Examples 1 to 2, and a cement mortar composition having dimensions of 4 x 4 x 16 The specimens were fabricated using 4 × 4 × 1 cm (for bonding strength test) molds for compression and bending strength tests, for drying shrinkage test, for chloride ion penetration depth test and for water absorption test, Curing was carried out to prepare specimens.

≪ Test Example 2 > Slump-flow measurement

Table 1 shows the workability of the cement mortar composition prepared according to Examples 1 to 3 and the cement mortar composition prepared according to Comparative Examples 1 to 2 in comparison.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Slump Flow (cm) 275 279 288 215 258

As shown in Table 1, the cement mortar composition prepared according to Examples 1 to 3 had a slump-flow value without bleeding and material separation as compared with the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2 Respectively. It was confirmed that the cement mortar composition prepared according to Examples 1 to 3 had excellent flowability and workability.

≪ Test Example 3 >

In order to compare the physical properties of the cement mortar composition prepared according to Examples 1 to 3 and the cement mortar composition prepared according to Comparative Examples 1 to 2, the specimens prepared in Test Example 1 were subjected to KS F 2477 (strength test method of polymer cement mortar), KS F 4916 (polymer for cement admixture), and the results are shown in Table 2 below.

division Strength (kgf / ㎠) compression warp adhesion 4 hours 1 day 7 days 4 hours 1 day 7 days 4 hours 1 day 7 days Example 1 215 318 408 63 84 100 18 22 25 Example 2 229 325 415 68 89 110 20 23 27 Example 3 235 337 428 72 96 120 21 25 30 Comparative Example 1 - 220 329 - 38 52 - 11 15 Comparative Example 2 198 302 382 58 75 93 15 19 22

As shown in Table 2, the cement mortar compositions prepared according to Examples 1 to 3 exhibited excellent initial compressive strength compared to the cement mortar compositions prepared according to Comparative Example 1 and Comparative Example 2 The cement mortar composition prepared according to Examples 1 to 3 shows a comparative example 1 and a comparative example 2 when the polymer admixture is used. The bending strength and the adhesive strength of the cement mortar composition were superior to those of the cement mortar composition prepared according to the present invention.

≪ Test Example 4 > Measurement of shrinkage ratio

After the same specimen as in Test Example 1 was prepared, the drying shrinkage ratio was measured by KS F 2424 (length change test method for mortar and concrete). The results are shown in Table 3 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Length change (%) 0.04 0.03 0.02 0.11 0.07

As shown in Table 3, the cement mortar composition prepared according to Examples 1 to 3 had a significantly lower shrinkage than the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2. It can be seen that the cement mortar composition prepared according to Examples 1 to 3 is more resistant to shrinkage after shrinkage than the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2, .

≪ Test Example 5 > Chloride ion penetration depth

In order to compare chloride ion penetration depths of the cement mortar composition prepared according to Examples 1 to 3 and the cement mortar composition prepared according to Comparative Examples 1 to 2, , A test was conducted by JIS A 6203 (polymer dispersion for cement admixture and re-oil type powder resin), and the results are shown in Table 4 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Chloride ion penetration depth (mm) 0.6 0.4 0.3 2.5 0.8

As shown in Table 4, the cement mortar composition prepared according to Examples 1 to 3 had a lower chloride ion penetration depth than the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2, And the resistance was high.

≪ Test Example 6 >

In order to compare the absorption rates of the cement mortar composition prepared according to Examples 1 to 3 with the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2, each of the specimens prepared in Test Example 1 was subjected to KS F 4916 (polymer for cement admixture), and the results are shown in Table 5 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Absorption Rate (%) 0.4 0.3 0.2 2.0 0.8

As shown in Table 5, the cement mortar composition prepared according to Examples 1 to 3 of the present invention showed a very low absorption rate as compared with the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2. It was found that the water penetration was low due to the influence of the polymer admixture and the water resistance was excellent.

≪ Test Example 7 >

The cement mortar composition prepared according to Examples 1 to 3 and the cement mortar composition prepared according to Comparative Examples 1 and 2 were subjected to a neutralization depth test according to JIS A 1171 (Test Method for Polymer Cement Mortar) The results are shown in Table 6.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Neutralization depth (mm) 0.3 0.2 0.2 1.4 0.6

As shown in Table 6 above, the cement mortar composition prepared according to Examples 1 to 3 has a lower neutralization depth than the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2, and thus has a high resistance to neutralization .

<Test Example 8>

The cement mortar composition prepared according to Examples 1 to 3 and the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2 were subjected to a freeze-thaw resistance test according to the method specified 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 comparative examples according to the freeze-thaw resistance test.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Durability index 92 93 94 59 90

As shown in Table 7, the durability index of the cement mortar composition prepared according to Examples 1 to 3 is much higher than that of the cement mortar composition prepared according to Comparative Example 1 and Comparative Example 2, Able to know.

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)

Wherein the polymer admixture comprises 75 to 99% by weight of methyl methacrylate-styrene, 10 to 60% by weight of a quick-setting binder, 10 to 60% by weight of a fine aggregate, 0.01 to 30% 0.1 to 10 wt% of methyl methacrylate-butadiene, 0.1 to 10 wt% of butyl acrylate-styrene, 0.1 to 10 wt% of acrylonitrile, and 0.01 to 5 wt% of vinyl acetate,
The quick-setting binder is usually 20 to 90 wt% of Portland cement, 5 to 50 wt% of calcium or magnesium sulfoaluminate, 0.1 to 20 wt% of alumina cement, 0.1 to 20 wt% of calcium aluminate, 0.1 to 20 wt% 0.1 to 20% by weight of zeolite, 0.1 to 10% by weight of gypsum and 0.01 to 5% by weight of aluminum powder, based on the total weight of the cement mortar composition. The method of claim 1,
Wherein the polymer admixture further comprises 0.001 to 3 wt% of at least one selected from the group consisting of polyethylene oxide, urethane and polycarboxylic acid to improve self-leveling. The method according to claim 1,
Wherein the polymer admixture further comprises 0.001 to 5% by weight of at least one material selected from the group consisting of polyvinyl methyl ether, polyvinyl alcohol and polyvinyl amine for preventing material separation. The method according to claim 1,
Wherein the polymer admixture further comprises 0.001 to 5 wt% of a polypropylene emulsion to improve water resistance and abrasion resistance. delete The method according to claim 1,
Wherein the quick-setting binder further comprises 0.001 to 5% by weight of at least one material selected from the group consisting of polycarboxylic acids, naphthalene, melamine and lignin, or one or more substances selected from methylcellulose, starch and gum, And further comprises 0.01 to 10% by weight of calcium carbonate, 0.01 to 5% by weight of reinforcing fibers, or 0.1 to 10% by weight of aluminum sulfate. Flowable cement mortar composition. The method according to claim 6,
Wherein the reinforcing fiber is made of one or more materials selected from nylon fiber, polyethylene, polypropylene, glass fiber, and carbon fiber. Chipping a portion of the concrete structure where surface cracks due to scaling, aggregate dropout, micro-cracks due to plastic cracks have occurred,
Cleaning the impurities or slurry of the chipped portion,
Applying a primer to the chipped portion,
And curing and curing the cement mortar composition according to claim 1 at the top of the primer-coated surface. Removing laitance or impurities on the surface of the concrete structure,
Applying a primer to a site where the layane or impurities have been removed,
A method for protecting a surface of a concrete structure, comprising curing and curing the cement mortar composition according to any one of claims 1 to 7 on the primer-coated upper surface to increase the compatibility of the concrete structure.