KR101368214B1 - Polymer cement concrete composite for revealing high early strength and repairing method of concrete structure using the composite - Google Patents

Abstract

The present invention comprises: 3-28 wt% of cement based binding agent; 28-62 wt% of fine aggregate; 20-55 wt% of coarse aggregate; 0.1-10 wt% of water; and 0.1-15 wt% of polymer based binding agent. The polymer based binding agent comprises: 10-70 wt% of styerene ; 10-45 wt% of butyl acrylate; 5-35 wt% of ethyl acrylate; 0.1-20 wt% of itaconic acid; and 0.1-20 wt% of poly methyl acrylate. The cement based binding agent usually comprises: 20-80 wt% of Portland cement; 10-60 wt% of amorphous calcium aluminate; 0.1-10 wt% of calcium alumna cement; 0.01-10 wt% of gypsum; 0.01-20 wt% of gellite powder; 0.01-10 wt% of powder water repellent; and 0.01-10 wt% of moldenite. The concrete composite of the present invention can improve workability and durability of the concrete, especially degradation of the concrete can be reduced by improving flexural rigidity, tensile strength, early age strength and long age strength.

Description

Polymer cement concrete composite for revealing high early strength and repairing method of concrete structure using the composite}

The present invention relates to a polymer cement concrete composition and a repair method of a concrete structure using the same, and more particularly, an early strength-expressing polymer cement concrete composition used for repairing a road surface, bridge bridge pavement, urgent repair work, etc. It relates to the repair method of the concrete structure used.

In general, polymer cement mortar is widely used for repair and reinforcement of corrosion or erosion sites such as bridge decks, road surfaces and lower bridge parts. The hardened Portland cement has the advantages of quick curing time and early strength development compared with portland cement. Contrary to this, penetration of chloride or water occurs, which causes corrosion of concrete.

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.

In order to solve these problems, a material using polymer dispersion is used as an alternative method, but the material cost is high.

Therefore, in order to solve such a problem, polymer cement concrete and non-shrinkage concrete have been developed and used as technical aspects.

On the other hand, in terms of economics and industry, it is also necessary to improve the strength and durability of the concrete to obtain a reduction in the maintenance cost.

In the recent emergency repair work, superhard latex modified concrete is added to the superhard cement with latex resin.

However, the cemented carbide latex modified concrete has a very high viscosity latex, which causes the concrete to adhere to the work tool during the finishing work to smooth the surface of the concrete. Since this is very short, about 20 minutes, the construction cost, such as workability deterioration, and the cement price is very expensive, it is inevitable to increase the construction cost.

Republic of Korea Patent Publication No. 10-1119237

The problem to be solved by the present invention is to improve the workability of the concrete composition by adding a polymer-based binder and cement-based binder mixed with styrene, butyl acrylate, ethyl acrylate, itaconic acid and polymethyl acrylate, durability of concrete In particular, the present invention provides an early strength expressive polymer cement concrete composition and concrete repair method using the same, which can reduce the defect of concrete by improving bending strength, tensile strength, initial strength, long-term strength, salt resistance and freeze-thawing resistance. Is in.

The present invention comprises 3 to 28% by weight cement binder, 28 to 62% by weight fine aggregate, 20 to 55% by weight coarse aggregate, 0.1 to 10% by weight water and 0.1 to 15% by weight polymer binder, the polymer binder 10 to 70% by weight of styrene, 10 to 45% by weight of butyl acrylate, 5 to 35% by weight of ethyl acrylate, 0.1 to 20% by weight of itaconic acid and 0.1 to 20% by weight of polymethyl acrylate. The binder is usually 20 to 80% by weight of Portland cement, 10 to 60% by weight of amorphous calcium aluminate, 0.1 to 10% by weight of calcium alumina cement, 0.01 to 10% by weight of gypsum, 0.01 to 20% by weight of fine powder of powder, 0.01 to 20% by weight of water repellent It provides an early strength expressive polymer cement concrete composition comprising 10% by weight and 0.01 to 10% by weight of mordenite.

The polymeric binder may further comprise 0.01 to 10% by weight of methyl methacrylate.

In addition, the polymeric binder may further comprise 0.01 to 10% by weight of polyethylene glycol monomethacrylate.

In addition, the polymeric binder may further comprise 0.01 to 10% by weight of a polyurethane emulsion.

The cement-based binder may further comprise 0.01 to 10% by weight of alumina powder.

In addition, the cement-based binder may further comprise 0.01 to 20% by weight of at least one material selected from blast furnace slag, fly ash and silica fume.

In addition, the cement-based binder may further comprise 0.001 to 5% by weight of at least one material separation inhibitor selected from methyl cellulose, starch and gum.

In addition, the cement-based binder further comprises 0.001 to 5% by weight of at least one accelerator selected from calcium salt, chloride, sulfate, potassium hydroxide, sodium hydroxide, carbonate (which is a carbonate except lithium carbonate), formic acid or salts thereof and lithium carbonate. can do.

In addition, the present invention, by chipping the site where the concrete structure is deteriorated or attached to impurities using a crusher and water jet (Chipping) to remove the deterioration site or impurities, primers (primers) to the deterioration site or the site from which impurities are removed )) And restoring the cross section of the deterioration site or the site from which impurities are removed by pouring the early strength-expressing polymer cement concrete composition on top of the primer-coated site; And it provides a repair method of the concrete structure comprising the step of applying a curing agent on top of the cast-expressed polymer cement concrete composition.

The primer may be made of one or more materials selected from styrene butadiene rubber latex, poly acrylic ester, ethylene vinyl acetate, and the polymeric binder.

According to the present invention, by using a polymer-based binder mixed with styrene, butyl acrylate, ethyl acrylate, itaconic acid and polymethyl acrylate in the early strength-expressing polymer cement concrete composition to improve the workability of the concrete composition The durability is improved, and in particular, the bending strength and tensile strength is improved.

In addition, the use of cement-based binder has the effect of improving the initial strength and long-term strength expression, durability, salt resistance, freeze thaw resistance and the like.

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.

Early strength-expressing polymer cement concrete composition according to a preferred embodiment of the present invention is a cement-based binder 3 to 28% by weight, fine aggregate 28-62% by weight, coarse aggregate 20-55% by weight, water 0.1-10% by weight and polymer-based binder It contains 0.1-15 weight%.

Aggregate is divided into fine aggregate and coarse aggregate, and fine grains of less than 5mm in diameter are called fine aggregates and coarse aggregates of larger than 5mm in particle size. The fine aggregate is preferably contained in the early strength-expressing polymer cement concrete composition 28 to 62% by weight, and the coarse aggregate is preferably contained in the early strength-expressing polymer cement concrete composition 20 to 55% by weight.

The cement binder is usually 20 to 80% by weight of Portland cement, 10 to 60% by weight of amorphous calcium aluminate, 0.1 to 10% by weight of calcium alumina cement, 0.01 to 10% by weight of gypsum, and 0.01 to 20% by weight of gelite fine powder. 0.01 to 10% by weight of powder water repellent and 0.01 to 10% by weight of mordenite.

It is preferable to use the ordinary Portland cement specified in KS. The crude steel portland cement is preferably contained 20 to 80% by weight in the cement-based binder.

Increasing the weight ratio of the amorphous calcium aluminate shows a fast curing characteristics, when the content of the amorphous calcium aluminate is less than 10% by weight of the concrete strength and cracking inhibitory effect is weak, the amorphous calcium aluminate content of 60 If the weight percentage is exceeded, the early strength is excellent, but it is not economical due to poor workability and high manufacturing cost.

Increasing the weight ratio of the calcium alumina cement shows a fast curing characteristics, when the content of the calcium alumina cement is less than 0.1% by weight of the concrete strength and cracking inhibitory effect is weak, the calcium alumina cement content of 10% by weight If exceeded, early strength is excellent, but it is not economical due to poor workability and high manufacturing cost.

The gypsum is used for initial strength development. The gypsum can be anhydrous gypsum or anthracite. Increasing the content of the gypsum exhibits fast curing characteristics, when the content of the gypsum is less than 0.01% by weight, the initial strength improvement effect of the early strength-expressing polymer cement concrete composition is weak, and the content of the gypsum exceeds 10% by weight. In this case, due to the fast curing property, good physical properties can be obtained, but workability and durability may be degraded.

The gellite fine powder is used for latent hydraulic properties, long-term strength development and durability enhancement. Preferably, the gellite fine powder is contained in the cement-based binder 0.01 to 20% by weight. When the content of the gellite fine powder is less than 0.01% by weight, the effect of improving the long-term strength of the early strength-expressing polymer cement concrete composition is insignificant, and when the content of the gellite fine powder is more than 20% by weight, the workability is improved but the initial strength is improved. Expression may be lowered.

The powder water repellent is used to improve the water resistance. Preferably, the powder water repellent is contained in the cement binder in an amount of 0.01 to 10% by weight. When the content of the powder repellent is less than 0.01% by weight, the effect of improving water resistance is insufficient. When the content of the powder repellent is more than 10% by weight, the effect of improving water resistance may be lowered. As the powder repellent, a silicon-based powder repellent, stearate metal soaps-based powder repellent, or the like may be used.

The mordenite is used for improving durability. The mordenite is preferably contained in the cement-based binder 0.01 to 10% by weight. When the content of the mordenite is less than 0.01% by weight, the durability enhancement effect may be weak, and when the content of the mordenite exceeds 10% by weight, durability may be improved but workability may be deteriorated.

The cement-based binder may further comprise 0.01 to 10% by weight of alumina powder. The alumina powder is used to improve initial strength development and dry shrinkage. The alumina powder is preferably contained in 0.01 to 10% by weight in the cement-based binder. When the content of the alumina powder is less than 0.01% by weight, the hay shrink reduction effect is insufficient, and when the content of the alumina powder exceeds 10% by weight, there is an initial strength expression effect, but workability may be reduced.

In addition, the cement-based binder may further comprise 0.01 to 20% by weight of at least one material selected from blast furnace slag, fly ash and silica fume. The at least one material selected from blast furnace slag, fly ash and silica fume is used to improve latent hydraulic properties, long-term strength development and durability. At least one material selected from the blast furnace slag, fly ash and silica fume is preferably contained in the cement-based binder 0.01 to 20% by weight. When the content of one or more materials selected from the blast furnace slag, fly ash and silica fume is less than 0.01% by weight, the effect of improving the long-term strength of the early strength-expressing polymer cement concrete composition is weak, and the selected one of the blast furnace slag, fly ash and silica fume 1 If the content of more than 20% by weight of the species is improved workability, but the initial strength may be reduced.

In addition, the cement-based binder may further comprise 0.001 to 5% by weight of at least one material separation inhibitor selected from methyl cellulose, starch and gum. The material separation inhibitor is used to prevent material separation of the cement binder and improve workability. The material separation preventing agent may be methylcellulose, starch, gum or the like, but it is preferable to use a starch-type material separation preventing agent with little decrease in strength. The material separation inhibitor is preferably contained in 0.001 to 5% by weight in the cement-based binder.

In addition, the cement-based binder may further comprise 0.01 to 5% by weight of a reducing agent. The water reducing agent is used to enhance strength and durability. Examples of the water reducing agent include naphthalene-based, melamine-based, and polycarboxylic acid-based water reducing agents, but it is preferable to use a polycarboxylic acid-based water reducing agent. The water reducing agent is preferably contained in 0.01 to 5% by weight in the cement binder.

In addition, the cement-based binder may further comprise 0.001 to 5% by weight of a retardant. The retarder may be used to delay the hardening by gypsum in order to secure workability for a certain time, it is preferably contained in 0.001 to 5% by weight in the cement-based binder. As the retarder, generally well-known substances can be used, for example, sugars such as glucose, glucose, textine, dextran, gluconic acid, malic acid, citric acid, citric acid or salts thereof, aminocarboxylic acids Or salts thereof, phosphonic acids or derivatives thereof, polyhydric alcohols such as glycerin, and the like.

In addition, the cement-based binder further comprises 0.001 to 5% by weight of at least one accelerator selected from calcium salt, chloride, sulfate, potassium hydroxide, sodium hydroxide, carbonate (which is a carbonate except lithium carbonate), formic acid or salts thereof and lithium carbonate. can do. The promoter is very fast when in contact with water, and when used in combination with cement, it is possible to obtain the compressive strength obtained after several days in a few hours. The promoters are generally well known substances, for example calcium formate, calcium chloride, calcium salts such as calcium nitrate, chlorides such as magnesium chloride, sulfates, potassium hydroxide, sodium hydroxide, carbonates (carbonates other than lithium carbonate), formic acid Or a salt thereof, lithium carbonate, or the like, and the promoter is preferably contained in the cement binder in an amount of 0.001 to 5% by weight.

The polymer binder is used to improve the workability, strength and durability of the concrete, 10 to 70% by weight of styrene, 10 to 45% by weight of butyl acrylate, 5 to 35% by weight of ethyl acrylate, 0.1 itaconic acid -20 wt% and 0.1-20 wt% of polymethylacrylate.

The styrene is used to adjust elasticity, compressive strength and viscoelasticity of the polymeric binder. The styrene is preferably contained in the polymer binder 10 to 70% by weight. When the content of styrene is less than 10% by weight, the strength and viscoelasticity improvement effect is reduced. When the content of the styrene is more than 70% by weight, the strength and viscoelasticity improvement effect is excellent, but the viscosity is lowered, resulting in poor workability.

The butyl acrylate is used to improve the ductility and viscoelasticity of the polymeric binder. The butyl acrylate is preferably contained 10 to 45% by weight in the polymer binder. When the content of the butyl acrylate exceeds 45% by weight, the ductility and viscoelasticity is improved, but the viscosity is lowered, the workability is lowered and the price competitiveness is lowered. When the content of the butyl acrylate is less than 10% by weight, the effect of improving the ductility and viscoelasticity It may be weak.

The ethyl acrylate is used to improve the ductility, bending and adhesion strength of the polymeric binder. The ethyl acrylate is preferably contained 5 to 35% by weight in the polymer binder. When the content of the ethyl acrylate exceeds 35% by weight, the ductility, bending and adhesion strength is improved, but the viscosity is high, the workability may be lowered. When the content of the ethyl acrylate is less than 5% by weight, the ductility, bending and adhesion strength is improved The effect may be weak.

The itaconic acid is used to control the dispersion stability, mixing and air amount of the polymeric binder. It is preferable that the itaconic acid is contained in the polymer binder in an amount of 0.1 to 20% by weight. If the content of itaconic acid is more than 20% by weight, the dispersion stability and the mixing property may be improved but the price competitiveness may be deteriorated. If the content of itaconic acid is less than 0.1% by weight, .

The polymethyl acrylate is used to improve the dispersibility and water resistance of the polymeric binder. The polymethyl acrylate is preferably contained 0.1 to 20% by weight in the polymer binder. When the content of the polymethyl acrylate is more than 20% by weight, the dispersibility and water resistance is improved, but the viscosity is high, the workability may be lowered and the price competitiveness is lowered. When the content of the polymethyl acrylate is less than 0.1% by weight, dispersibility And the effect of improving water resistance may be weak.

The polymeric binder may further comprise 0.01 to 10% by weight of methyl methacrylate in order to improve strength and durability. The methyl methacrylate is preferably contained in 0.01 to 10% by weight in the polymer binder.

In addition, the polymeric binder may further comprise 0.01 to 10% by weight of polyethylene glycol monomethacrylate in order to improve dispersibility. The polyethylene glycol monomethacrylate is preferably contained in 0.01 to 10% by weight in the polymer binder.

In addition, the polymeric binder may further comprise 0.01 to 10% by weight of a polyurethane emulsion in order to improve the adhesion and adhesive strength. The polyurethane emulsion is preferably contained in 0.01 to 10% by weight in the polymer binder.

In addition, the polymeric binder may further comprise 0.001 to 5% by weight of an antifoaming agent. The antifoaming agent is used to remove the pores in the concrete to increase the strength and durability of the concrete, it is preferably contained in 0.001 to 5% by weight in the polymer-based binder. As the antifoaming agent, generally known materials such as alcoholic antifoaming agents, silicone antifoaming agents, fatty acid antifoaming agents, oil antifoaming agents, ester antifoaming agents, oxyalkylene antifoaming agents and the like can be used. 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 agent include kerosene, animal and plant oil, castor oil, and the ester-based antifoaming agents include solitol trioleate and glycerol monoricinolate. Examples of the oxyalkylene antifoaming agents include polyoxyalkylene, acetylene ethers, polyoxyalkylene diazoxide esters, polyoxyalkylene alkylamines, and the like. Examples of the antifoaming agent include glycol.

In addition, the polymeric binder may further comprise 0.001 to 5% by weight of an air entrainer. The air entrainer is used to improve workability by improving the dispersibility of the early strength-expressing polymer cement concrete composition. The air entrainer may be polycarboxylic acid, naphthalene or melamine, but it is preferable to use a polycarboxylic acid air entrainer. The air entrainer is preferably contained in 0.001 to 5% by weight of the polymer binder.

In the early strength-expressing polymer cement concrete composition according to a preferred embodiment of the present invention, 3 to 28% by weight of cement-based binder, 28 to 62% by weight of aggregate and 20 to 55% by weight of coarse aggregate are added to the mixer, followed by forced stirring. It may be prepared by further mixing 0.1 to 10% by weight of water and 0.1 to 15% by weight of the polymeric binder and stirring for a predetermined time (for example, 1 to 10 minutes).

Repairing method of a concrete structure according to a preferred embodiment of the present invention, the step of chipping (Chipping) the deteriorated or impurity-attached site using a crusher and waterjet to remove the deterioration site or impurities, and Applying a primer (primer) to the site where the impurities have been removed, and by placing the early strength-expressing polymer cement concrete composition on top of the site where the primer is applied to recover the cross section of the deterioration site or the site from which impurities are removed And applying a curing agent on top of the poured early strength-expressing polymer cement concrete composition.

Hereinafter, the concrete structure is used as a meaning including all structures made of concrete as structures of road roads, bridge bridges, concrete slabs of bridges, lower bridges, and the like.

The primer means a material that facilitates the early strength-expressing polymer cement concrete composition to be attached to the concrete structure, styrene butadiene rubber latex, poly acryl ester (PAE), ethylene vinyl Acetate (Ethylene Vinyl Acetate; EVA) and at least one material selected from the polymer-based binder. At this time, the solid content of the primer is preferably lowered to about 10% by weight construction. When the solid content of the primer is used in excess of 10% by weight, the thickness of the coating may be thick, thereby lowering the adhesion performance.

Hereinafter, the embodiments of the early strength-expressing polymer cement concrete composition according to the present invention will be described in more detail, and the present invention is not limited by the following examples.

≪ Example 1 >

18% by weight of cement-based binder, 42% by weight of fine aggregate and 34% by weight of coarse aggregate were added to the mixer forcibly stirring, and then 4% by weight of water and 2% by weight of polymer-based binder were further mixed and stirred for 2 minutes to develop early strength. A polymer cement concrete composition was prepared.

The cement-based binder is usually 43% by weight of Portland cement, 30% by weight of amorphous calcium aluminate, 5% by weight of calcium alumina cement, 5% by weight of gypsum, 10% by weight of fine powder of gelite, 4% by weight of water repellent, 1% by weight of calcium silicate, 0.5% by weight of reducing agent, 0.5% by weight of material separation inhibitor, 0.5% by weight of accelerator and 0.5% by weight of retardant were used in combination. As the powder repellent, a silicon-based powder repellent was used, as the water-reducing agent, a polycarboxylic acid-based water-reducing agent was used, as the material separation inhibitor, a starch-based material separation inhibitor was used, and the accelerator was lithium carbonate. Citric acid was used as a retardant.

The polymer binder is 45% by weight of styrene, 30% by weight of butyl acrylate, 15% by weight of ethyl acrylate, 7% by weight of itaconic acid, 2% by weight of polymethyl acrylate, 0.5% by weight of antifoaming agent and 0.5% by weight of air entrainer. Was used by mixing. The antifoaming agent was used glycol, and the polycarboxylic acid-based air entrainer was used as the air entrainer.

<Example 2>

18% by weight of cement-based binder, 42% by weight of fine aggregate and 34% by weight of coarse aggregate were added to the mixer forcibly stirring, and then 4% by weight of water and 2% by weight of polymer-based binder were further mixed and stirred for 2 minutes to develop early strength. A polymer cement concrete composition was prepared.

The cement-based binder is usually 43% by weight of Portland cement, 30% by weight of amorphous calcium aluminate, 5% by weight of calcium alumina cement, 5% by weight of gypsum, 10% by weight of fine powder of gelite, 4% by weight of water repellent, 1% by weight of calcium silicate, 0.5% by weight of reducing agent, 0.5% by weight of material separation inhibitor, 0.5% by weight of accelerator and 0.5% by weight of retardant were used in combination. As the powder repellent, a silicon-based powder repellent was used, as the water-reducing agent, a polycarboxylic acid-based water-reducing agent was used, as the material separation inhibitor, a starch-based material separation inhibitor was used, and the accelerator was lithium carbonate. Citric acid was used as a retardant.

The polymer binder is 40% by weight of styrene, 32% by weight of butyl acrylate, 16% by weight of ethyl acrylate, 8% by weight of itaconic acid, 3% by weight of polymethyl acrylate, 0.5% by weight of antifoaming agent and 0.5% by weight of air entrainer. Was used by mixing. The antifoaming agent was used glycol, and the polycarboxylic acid-based air entrainer was used as the air entrainer.

<Example 3>

18% by weight of cement-based binder, 42% by weight of fine aggregate and 34% by weight of coarse aggregate were added to the mixer forcibly stirring, and then 4% by weight of water and 2% by weight of polymer-based binder were further mixed and stirred for 2 minutes to develop early strength. A polymer cement concrete composition was prepared.

The cement-based binder is usually 43% by weight of Portland cement, 30% by weight of amorphous calcium aluminate, 5% by weight of calcium alumina cement, 5% by weight of gypsum, 10% by weight of fine powder of gelite, 4% by weight of water repellent, 1% by weight of calcium silicate, 0.5% by weight of reducing agent, 0.5% by weight of material separation inhibitor, 0.5% by weight of accelerator and 0.5% by weight of retardant were used in combination. As the powder repellent, a silicon-based powder repellent was used, as the water-reducing agent, a polycarboxylic acid-based water-reducing agent was used, as the material separation inhibitor, a starch-based material separation inhibitor was used, and the accelerator was lithium carbonate. Citric acid was used as a retardant.

The polymer binder is 35% by weight of styrene, 34% by weight of butyl acrylate, 17% by weight of ethyl acrylate, 9% by weight of itaconic acid, 4% by weight of polymethyl acrylate, 0.5% by weight of antifoaming agent and 0.5% by weight of air entrainer. Was used by mixing. The antifoaming agent was used glycol, and the polycarboxylic acid-based air entrainer was used as the air entrainer.

Comparative Examples are presented to more easily understand the characteristics of Examples 1 to 3 above, and Comparative Examples 1 to 2 present ordinary portland cement concrete compositions and cement concrete compositions that are currently widely used. will be.

&Lt; Comparative Example 1 &

Usually, 20% by weight of Portland cement, 42% by weight of aggregate, 34% by weight of coarse aggregate, and 4% by weight of water were added to a mixer to prepare a concrete composition by forced stirring.

Comparative Example 2

Usually, 18% by weight of Portland cement, 42% by weight of aggregate, and 34% by weight of coarse aggregate are added to the mixer and forcibly stirred. Then, 4% by weight of water and 2% by weight of styrene are further mixed and stirred for 2 minutes to prepare a polymer cement concrete composition. Prepared.

The following test examples show the experimental results comparing the characteristics of the examples according to the invention with the characteristics of Comparative Examples 1 and 2 to more easily understand the characteristics of Examples 1 to 3 according to the present invention .

&Lt; Test Example 1 >

The slump test of the early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 and the cement concrete composition prepared according to Comparative Examples 1 and 2 according to the method specified in KS F 2402 ) Shows the result. The slump test is to test the toughness of the dough, such as the age and consistency of the concrete, the higher the value means the workability (workability), that is, excellent workability when pouring concrete.

Table 1 below shows the change of slump over time.

division Slump (cm) Immediately after stirring After 20 minutes After 30 minutes After 40 minutes After 60 minutes Example 1 21 17 14 11 9 Example 2 20 17 15 12 10 Example 3 21 18 15 14 12 Comparative Example 1 15 10 7 5 6 Comparative Example 2 18 13 9 6 4

As shown in Table 1 above, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 were superior in workability than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

&Lt; Test Example 2 &

The results of the compressive strength test of the early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 and the concrete composition prepared according to Comparative Examples 1 and 2 according to the method specified in KS F 2405 It is shown.

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

division Compressive strength (kgf / ㎠) After 12 hours 24 hours later 3 days later After 28 days Example 1 265 315 369 428 Example 2 278 325 380 445 Example 3 289 336 399 470 Comparative Example 1 - - 206 408 Comparative Example 2 - - 210 406

As shown in Table 2, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 had significantly higher compressive strength than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

&Lt; Test Example 3 >

The early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 and the concrete composition prepared according to Comparative Example 1 and Comparative Example 2 according to the method specified in KS F 2408 shows the results of the bending strength measured will be.

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

division Bending strength (kgf / ㎠) After 12 hours 24 hours later After 7 days After 28 days Example 1 58 63 70 78 Example 2 60 66 74 83 Example 3 63 68 78 85 Comparative Example 1 - - 42 55 Comparative Example 2 - - 50 70

As shown in Table 3 above, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 had significantly higher flexural strength than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

<Test Example 4>

Adhesive strength of the cement concrete composition prepared according to Examples 1 to 3 and Comparative Examples 1 to 2 was measured according to the method defined in KS F 2762, and the results are shown in Table 4.

division Adhesion strength (kgf / cm 2) After 12 hours 24 hours later 3 days later After 28 days Example 1 17 20 22 24 Example 2 18 21 23 26 Example 3 20 23 25 28 Comparative Example 1 - - - 17 Comparative Example 2 15 17 19 21

As shown in Table 4, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 had significantly higher adhesion strengths than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

&Lt; Test Example 5 >

Measurement of Absorption Rate according to the method defined in KS F 4004 (cement brick) of the early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 and the concrete composition prepared according to Comparative Examples 1 and 2 The results are shown. If the water absorption rate is high, impurities or water penetrate into the interior of the concrete, the porosity increases in the interior of the concrete, thereby causing a problem of causing damage to the structure. That is, the lower the absorptivity, the more the strength of the concrete is improved after curing.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Absorption Rate (%) 1.1 0.9 0.6 3.0 1.4

As shown in Table 5 above, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 had lower absorption rates than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

&Lt; Test Example 6 >

Measurement results of the freeze thaw resistance test according to the method specified in KS F 2456 for the early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 and the concrete composition prepared according to Comparative Examples 1 and 2 It is shown. 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 6 shows the durability indices 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 90 92 93 60 88

As shown in Table 6 above, since the early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 is significantly higher than the cement concrete composition prepared according to Comparative Examples 1 and 2 It can be seen that durability is improved.

&Lt; Test Example 7 >

Early shrinkage-type polymer cement concrete compositions prepared according to Examples 1 to 3 and concrete compositions prepared according to Comparative Examples 1 and 2 were subjected to dry shrinkage by KS F 2424 (Test method for changing the length of concrete). It was measured, and the results are shown in Table 7 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Length change rate
(%) 0.04 0.04 0.03 0.11 0.08

As shown in Table 7, above, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 are reduced in shrinkage due to the reduced amount of dry shrinkage compared to the cement concrete compositions prepared according to Comparative Examples 1 and 2. It was confirmed that there was a reduction effect.

<Test Example 8>

The early strength-expressing polymer cement concrete composition prepared according to Examples 1 to 3 and the concrete composition prepared according to Comparative Examples 1 and 2 were subjected to a test according to JIS A 1171 (test method for polymer cement mortar). The results are shown in Table 8.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Neutralization Depth (mm) 0.5 0.3 0.2 1.4 0.8

As shown in Table 8 above, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 showed less neutralization penetration depth than the cement concrete compositions prepared according to Comparative Examples 1 and 2. It was confirmed that the resistance to neutralization is high.

&Lt; Test Example 9 >

The early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 and the concrete compositions prepared according to Comparative Examples 1 and 2 were tested according to JIS A 1171, and the results are shown in Table 9 below. Shown in

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Chloride ion
Penetration depth (mm) 1.3 1.1 0.9 3.4 1.8

As shown in Table 9 above, the early strength-expressing polymer cement concrete compositions prepared according to Examples 1 to 3 have a smaller chloride ion penetration depth than the cement concrete compositions prepared according to Comparative Examples 1 and 2. It appeared that resistance to salt was high.

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 (10)

3 to 28 weight percent cement-based binder, 28 to 62 weight percent of fine aggregate, 20 to 55 weight percent of coarse aggregate, 0.1 to 10 weight percent of water and 0.1 to 15 weight percent of polymer binder,
The polymeric binder includes 10 to 70% by weight of styrene, 10 to 45% by weight of butyl acrylate, 5 to 35% by weight of ethyl acrylate, 0.1 to 20% by weight of itaconic acid and 0.1 to 20% by weight of polymethyl acrylate. and,
The cement-based binder is usually 20 to 80% by weight of Portland cement, 10 to 60% by weight of amorphous calcium aluminate, 0.1 to 10% by weight of calcium alumina cement, 0.01 to 10% by weight of gypsum, 0.01 to 20% by weight of fine powder of gelatin, powder water repellent An early strength-expressing polymer cement concrete composition comprising 0.01 to 10% by weight and 0.01 to 10% by weight of mordenite.
The method of claim 1, wherein the polymeric binder is an early strength-expressing polymer cement concrete composition, characterized in that it further comprises 0.01 to 10% by weight of methyl methacrylate.
The method of claim 1, wherein the polymer-based binder is characterized in that the early strength expression polymer cement concrete composition characterized in that it further comprises 0.01 to 10% by weight polyethylene glycol monomethacrylate.
The method of claim 1, wherein the polymeric binder is an early strength expression type polymer cement concrete composition, characterized in that it further comprises 0.01 to 10% by weight polyurethane emulsion.
The method of claim 1, wherein the cement-based binder is an early strength expression type polymer cement concrete composition, characterized in that it further comprises 0.01 to 10% by weight of alumina powder.
The method of claim 1, wherein the cement-based binder is an early strength expression type polymer cement concrete composition characterized in that it further comprises 0.01 to 20% by weight of at least one material selected from blast furnace slag, fly ash and silica fume.
The method of claim 1, wherein the cement binder is premature strength-expressing polymer cement concrete, characterized in that it further comprises 0.001 to 5% by weight of at least one material separation inhibitor selected from methyl cellulose, starch and gum (Gum) Composition.
The method of claim 1, wherein the cement binder is calcium salt, chloride, sulfate, potassium hydroxide, sodium hydroxide, carbonate (which is a carbonate except lithium carbonate), formic acid or a salt thereof and at least one promoter of 0.001 to 5 weight Early strength-expressing polymer cement concrete composition, characterized in that it further comprises%.
Chipping the deteriorated or impurity-concrete structure by using a crusher and a waterjet to remove the deteriorated portion or impurities;
Applying a primer to a deterioration site or a site from which impurities are removed;
Restoring a cross section of the deterioration site or the site from which impurities are removed by pouring the early strength-expressing polymer cement concrete composition according to claim 1 on top of the application site of the primer; And
Repairing method of the concrete structure comprising the step of applying a curing agent on top of the poured early strength-expressing polymer cement concrete composition.
The method of claim 9, wherein the primer is styrene butadiene rubber latex, polyacrylic ester, ethylene vinyl acetate and the repair method of a concrete structure, characterized in that made of at least one material selected from the polymeric binder of claim 1.