KR101672713B1 - A high early strength cement concrete composition having the improved self-healing, durability and strength for road pavement and a repairing method of concrete structure using the same - Google Patents

Abstract

The present invention relates to a high early strength cement concrete composition having improved self-healing, durability and strength and a method for maintaining and repairing a concrete structure using the same and, more specifically, to a high early strength cement concrete composition having improved self-healing, durability and strength, and a method for maintaining and repairing a concrete structure using the same. The high early strength cement concrete composition comprises: 3 to 35 wt.% of a high early strength cement-based binder; 20 to 75 wt% of a fine aggregate; 20 to 75 wt% of a coarse aggregate; 0.1 to 20 wt% of water; and 0.01 to 15 wt% of a functional admixture.

Description

Technical Field [0001] The present invention relates to a cementitious cement concrete composition having improved self-healing property, durability and strength, and a method for maintaining and repairing a concrete structure using the same. the same}

The present invention relates to a crude steel cement concrete composition having improved self-healing property, durability and strength, and a method for maintenance of a concrete structure using the same. More specifically, the present invention relates to a method for repairing a road surface or a bridge bridge, The present invention relates to a crude steel cement concrete composition having improved self-healing property, durability and strength, which is used for repairing concrete structures, and a method of maintaining and repairing concrete structures using the same.

Generally, chemical corrosion is a general term of deterioration phenomenon in which concrete is subjected to chemical action from the outside and the hydration product constituting the cement hardened body is deformed or decomposed to lose bonding ability. It is easy to be confused with deterioration phenomenon by existing neutralization, East Sea and salting, and it is put into concrete structure with existing repair mortar instead of sulfuric acid repair mortar, resulting in deterioration such as cracking or peeling in structure, And the like.

In general, the concrete pavement is rigid and has a limitation on the construction in the temperature and the surrounding environment, the curing period is long, the cracks due to drying shrinkage, the unfavorable riding comfort and comfort are disadvantageous, And some of them are applied to highway and medium-sized roads.

On the other hand, polymer cement mortar and concrete are widely used for maintenance and reinforcement of areas where corrosion and erosion of the bottom plate of the bridge, the road surface and the lower part of the bridge occur frequently. The crude steel Portland cement has advantages such as quick curing time and early strength development compared with portland cement. However, chloride or moisture penetration occurs, and concrete is corroded.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a crude steel cement concrete composition improved in self-healing property, durability and strength.

Another object of the present invention is to provide a method for maintenance of concrete structures using the crude steel cement concrete composition.

In order to solve the above-mentioned technical problems, the present invention provides a method for producing a cement composition, which comprises 3 to 35 wt% of crude steel cement based binder, 20 to 75 wt% of fine aggregate, 20 to 70 wt% of coarse aggregate, 0.1 to 20 wt% includes, said cementitious bonding material is steel powder also has 5,000 ~ 8,500cm ² / g of micro-cement 15 to 80% by weight, 1-45% by weight of calcium aluminate, the powder also has 3,500 ~ 4,500cm ² / g and SiO ₂ 1 to 25% by weight of blast furnace slag powder having a powder degree of 4000 to 7000 cm2 / g, 1 to 20% by weight of gypsum, 0.1 to 15% by weight of sodium silicate, 0.01 to 15% by weight of calcium stearate Wherein the functional admixture comprises from 45 to 98% by weight of styrene-butadiene, from 1 to 30% by weight of styrene-vinyl acetate, from 0.1 to 20% by weight of acrylonitrile-vinylidene chloride polymer 0.1 to 20% by weight of polyvinybutyral, and 0.01 to 15% by weight of hydroxyethylcellulose. Durability comprising the%, provides a self-healing property and the strength is improved steel concrete cement composition.

According to another aspect of the present invention, there is provided a method of maintaining and repairing concrete structures using the crude steel cement concrete composition, comprising the steps of:

(S1) chipping a portion where the concrete structure is deteriorated and the concrete is detached using a crusher and a water jet to remove impurities and deteriorated portions;

(S2) cleaning the removed portion with a vacuum suction vehicle;

(S3) In order to facilitate adhesion of the crude steel cement concrete composition to the concrete, improve the surface strength, to inhibit penetration of water and penetration of chlorine ions, and to improve water resistance, the functional admixture is applied to the cleaned area, Blooming with the polymer-cement mortar mixed with the polymer-cement mortar;

(S4) restoring or reinforcing a section of the deteriorated portion by placing the crude steel cement concrete composition on an upper portion coated with the functional admixture;

(S5) a step of performing a tinning for increasing the friction on the poured crude steel cement concrete composition; And

(S6) a step of applying a coating-forming curing agent or a surface penetration-preventing agent to the top of the tile-finished crude steel cement concrete composition.

In this case, if the reinforcing bars are exposed in the step of removing the impurities and the deteriorated portions, the method may further include a rust-preventive treatment step of applying rust-preventive after removing the rust.

According to the present invention, by using a functional admixture and a crude steel-cement based binder, workability of concrete can be improved, and strength of concrete, particularly tensile strength and adhesion strength, can be improved and durability can be greatly improved. In addition, not only is it possible to prevent whitening and neutralization, but also to accelerate initial hydration of cement and densification of texture, thereby making concrete in a closed form, thereby preventing surface cracking and expansion failure of concrete and exhibiting self-healing performance There is an effect that can be. On the other hand, it is possible to use almost all the methods generally used in production and construction methods of materials while satisfying all the properties required for packaging, i.e., watertightness, adhesion, durability and crack resistance, It has excellent effect.

The crude steel cement concrete composition of the present invention comprises 3 to 35% by weight of crude steel cement based binder, 20 to 75% by weight of fine aggregate, 20 to 70% by weight of coarse aggregate, 0.1 to 20% by weight of water and 0.01 to 15% .

The aggregate used in the present invention is classified into a fine aggregate and a fine aggregate having a particle diameter of 5 mm or less and a fine aggregate having a particle diameter larger than 5 mm. The fine aggregate is preferably contained in 20 to 75 wt% of the crude steel cement concrete composition of the present invention, and the coarse aggregate is preferably contained in 20 to 70 wt% of the crude steel cement concrete composition of the present invention.

Wherein the crude steel cement based binder comprises 15 to 80 wt% of microcement having a powder degree of 5,000 to 8,500 cm ² / g, 1 to 45 wt% of calcium aluminate, a powdery degree of 3,500 to 4,500 cm ² / g, a SiO ₂ content of 70% 1 to 20% by weight of gypsum powder, 0.1 to 15% by weight of sodium silicate, 0.01 to 10% by weight of calcium stearate, 1 to 30% And 0.01 to 10% by weight of aluminum oxide.

The ordinary Portland cement is preferably used as specified in KS, and it is preferable that the Portland cement is contained in an amount of 15 to 80% by weight based on the crude steel cement based binder.

The above-mentioned cemented carbide powder having a powder degree of 3,500 to 4,500 cm ² / g and an SiO ₂ content of 70% or more is used for obtaining an index and self-healing effect as well as improving pozzolanic characteristics, long-term strength development and durability. The cemented carbide powder is preferably contained in an amount of 1 to 30% by weight based on the crude steel cement based binder. If the content of the cyanophyll powder is less than 1 wt%, the performance improvement effect becomes insufficient. If the content is more than 30 wt%, initial strength development may be deteriorated.

The blast furnace slag powder is used as a latent hydraulic property for the development of long-term strength and the improvement of durability. The blast furnace slag powder is preferably contained in an amount of 1 to 25% by weight based on the crude steel cement based binder. It is preferable that the blast furnace slag powder has a powder degree of 4000 to 7000 cm2 / g. If the content of the blast furnace slag powder is less than 1% by weight, the long-time strength development and durability improving effect may be insufficient. If it exceeds 35% by weight, the initial strength development may be delayed.

The calcium aluminate (CA) and the gypsum are used for initial strength development and shrinkage prevention. The calcium aluminate (CA) and the gypsum are used to prevent the concrete from cracking by making the structure dense and to prevent shrinkage of the concrete.

The calcium aluminate is preferably contained in an amount of 5 to 45% by weight based on the crude steel cement based binder.

The gypsum may be an anhydrous gypsum or an alumite. The gypsum is preferably contained in an amount of 1 to 20% by weight based on the crude steel cement based binder.

The calcium aluminate and the gypsum exhibit fast curing characteristics when the weight ratio is increased. When the total content of the calcium aluminate and the gypsum is less than 6% by weight based on the crude steel cement based binder, the concrete strength and the effect of suppressing crack generation are small If the total content of the calcium aluminate and the gypsum exceeds 65% by weight, good physical properties can be obtained due to quick curing properties, but the production cost is high and it is not economical.

The sodium silicate is used for initial strength development. The sodium silicate is preferably contained in an amount of 0.1 to 15% by weight based on the crude steel cement based binder. If the content of the sodium silicate is less than 0.01 wt%, the effect of initial strength development is insufficient. If the content of the sodium silicate is more than 15 wt%, the curing is accelerated and the workability is decreased and the economical efficiency is decreased.

The calcium stearate is used to improve water repellency and water resistance. The calcium stearate is preferably contained in an amount of 0.01 to 10 wt% based on the crude steel cement based binder. If the content of calcium stearate is less than 0.01% by weight, water repellency and waterproofing effect may be weak. If the content of calcium stearate exceeds 10% by weight, strength The expression is decreased and the manufacturing cost is increased, which is not economical.

The aluminum oxide is used to improve abrasion resistance and chemical resistance. The aluminum oxide is preferably contained in an amount of 0.01 to 10% by weight based on the crude steel cement based binder. When the content of the aluminum oxide is less than 0.01% by weight, the effect of improving abrasion resistance and chemical resistance may be insignificant. When the content of the aluminum oxide exceeds 10% by weight, the abrasion resistance and the chemical resistance are improved. The workability is lowered and the manufacturing cost is increased, which is not economical.

The crude steel cement based binder may further include magnesium sulfoaluminate. The magnesium sulfoaluminate is used for initial strength development and prevention of shrinkage. The magnesium sulfoaluminate is preferably contained in an amount of 0.1 to 30% by weight based on the crude steel cement based binder.

The crude steel cement based binder may further include titanium oxide. The titanium oxide is used for improving the antifouling property. The titanium oxide is preferably contained in an amount of 0.01 to 5% by weight based on the crude steel cement based binder. If the content of the titanium oxide is less than 0.01% by weight, the antifouling performance effect may be insignificant. When the content of the titanium oxide is more than 5% by weight, And the manufacturing cost is increased, which is not economical.

The crude steel cement based binder may further include a water reducing agent. The water reducing agent is used to improve the strength and durability by reducing the water-cement ratio of the crude steel cement concrete composition. As the water reducing agent, a polycarboxylic acid type, melamine type or naphthalene type water reducing agent may be used. The water reducing agent is preferably a naphthalene-based water reducing agent having an excellent effect of improving the strength and durability and having an excellent effect of reducing the water-cement ratio, and is preferably contained in an amount of 0.001 to 5% by weight based on the crude steel cement based binder.

The crude steel cement based binder may further include a retarder. The retarder can be used to ensure workability for a certain period of time and to delay rapid curing. The retarder is preferably contained in an amount of 0.01 to 5% by weight based on the crude steel cement based binder. 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 functional admixture is used to improve the curing time, workability, strength and durability of the crude steel cement concrete composition, and the functional admixture is preferably contained in the crude steel cement concrete composition in an amount of 0.01 to 15% by weight. If the content of the functional admixture exceeds 15% by weight, the viscosity of the crude steel cement concrete composition is lowered to improve the workability (slump), but the hydration reaction may be delayed to lower the initial compressive strength and decrease the price competitiveness . If the content of the functional admixture is less than 0.01% by weight, the effect of improving the curing time, workability, strength and durability may be insignificant.

Wherein the functional admixture comprises 45 to 98% by weight of styrene-butadiene, 1 to 30% by weight of styrene-vinyl acetate, 0.1 to 20% by weight of acrylonitrile-vinylidene chloride polymer, 0.1 to 20% by weight of polyvinybutyral, And 0.01 to 15% by weight of hydroxyethylcellulose.

The styrene-butadiene is used to improve the bonding strength and endurance performance. The styrene-butadiene is preferably contained in an amount of 45 to 98 wt% with respect to the functional admixture. If the content of styrene-butadiene exceeds 98 wt%, the workability of the crude steel cement concrete composition improves, but the initial strength of the concrete may be lowered. If the content of styrene-butadiene is less than 45 wt%, the initial strength The expression is improved, but the workability is remarkably lowered.

The styrene-vinyl acetate is used to improve bending strength and toughness. It is preferable that the clistrene-vinyl acetate is contained in an amount of 1 to 30% by weight based on the functional admixture. If the content of the styrene-vinyl acetate exceeds 30% by weight, the viscosity of the crude steel cement concrete composition may increase and the slump may be lowered. If the content of the styrene-vinyl acetate is less than 1% by weight, The effect may be weak.

The acrylonitrile-vinylidene chloride polymer is used to improve chemical resistance and abrasion resistance. The acrylonitrile-vinylidene chloride polymer is preferably contained in an amount of 0.1 to 20% by weight based on the functional admixture. When the content of the acrylonitrile-vinylidene chloride polymer exceeds 20% by weight, the performance of the crude steel cement concrete composition But the price competitiveness may be deteriorated. If the content of the acrylonitrile-vinylidene chloride polymer is less than 0.1% by weight, the workability of the crude steel cement concrete composition may be improved, but the effect of improving the chemical resistance and wear resistance may be weak.

The polyvinybutyral is used to improve the adhesive strength and weatherability of the functional admixture. The polyvinyl butyral is preferably contained in an amount of 0.1 to 20% by weight based on the functional admixture. If the content of polyvinylbutylal exceeds 20 wt%, the adhesive strength and weatherability are not further improved and price competitiveness may be lowered. If the content of polyvinylbutylal is less than 0.1 wt%, workability, The effect of improving the adhesive strength and weatherability may be insufficient.

The hydroxyethyl cellulose is used to prevent the material separation by imparting the viscosity of the functional admixture. The hydroxyethyl cellulose is preferably contained in an amount of 0.01 to 15% by weight based on the functional admixture. If the content of hydroxyethylcellulose is less than 0.01% by weight, separation of the material tends to occur. If the content exceeds 15% by weight, the viscosity increases and the workability is lowered and the initial strength may be lowered.

The functional admixture may further include butyl acrylate-styrene. The butyl acrylate-styrene is used to improve workability, strength and durability. The butyl acrylate-styrene is preferably contained in an amount of 0.01 to 10% by weight based on the functional admixture. If the content of butyl acrylate-styrene is more than 10% by weight, separation of the material tends to occur. If the content of butylacrylate-styrene is less than 0.01% by weight, the effect of improving the strength and durability may be weak.

The functional admixture may further include methyl methacrylate butadiene. The methylmethacrylate butadiene is used to improve strength and durability. If the content of methylbutyrate methacrylate exceeds 10% by weight, the performance of the crude steel cement concrete composition is improved, but the price competitiveness is improved. If the content of the methylmethacrylate butadiene is less than 0.01% by weight, the effect of improving the strength and durability may be weak.

The functional admixture may further contain 0.001 to 5% by weight of a naphthalene-based water reducing agent. The naphthalene-based water reducing agent improves the strength and durability by reducing the water-cement ratio, and also improves the initial workability by delaying the hydration reaction of the crude steel cement.

The functional admixture may further contain 0.01 to 5% by weight of a silicone antifoaming agent. The silicone-based defoaming agent can reduce the air amount and decrease the air gap to improve strength and durability.

The crude steel cement concrete composition having improved durability according to a preferred embodiment of the present invention is prepared by mixing 3 to 35% by weight of crude steel-cement based binder, 20 to 75% by weight of fine aggregate and 20 to 70% by weight of coarse aggregate in a forced mixer, To 20% by weight of the functional admixture and 0.01 to 15% by weight of the functional admixture, followed by stirring for a predetermined time (for example, 1 to 10 minutes).

Hereinafter, a concrete structure maintenance method according to a preferred embodiment of the present invention will be described.

According to a preferred embodiment of the present invention, there is provided a method of maintaining a concrete structure using a crude steel cement concrete composition having improved self-healing property, durability and strength, comprising the steps of chipping a portion of a concrete structure where a concrete structure is deteriorated by using a crusher and a water jet, And removing the deteriorated portion; cleaning the removed portion with a vacuum suction vehicle; and making the crude steel cement concrete composition easy to adhere to concrete, improving surface strength, inhibiting water penetration and chlorine ion penetration Applying the functional admixture to the cleaned site or blooming the polymer admixture with the polymer admixture mixed with the functional admixture to improve the water resistance, and applying the functional admixture to the top of the crude granular cement Concrete tank A step of restoring or reinforcing a section of the deteriorated part by casting an artificial material, performing a tinning for increasing friction on the poured crude steel cement concrete composition, and forming a film on the tinned steel cement concrete composition As a curing agent or surface penetration protective agent.

In this case, if the reinforcing bars are exposed in the step of removing the impurities and the deteriorated portions, the method may further include a rust-preventive treatment step of applying rust-preventive after removing the rust.

In the case of chipping using the crusher and the water jet, the reinforcing bars of the concrete structure are not normally exposed, but when the deterioration is severe, the reinforcing bars may be exposed at the deteriorated portions. It is desirable to prevent corrosion.

According to the present invention, by using a functional admixture and a crude steel-cement based binder, workability of concrete can be improved, and strength of concrete, particularly tensile strength and adhesion strength, can be improved and durability can be greatly improved.

Hereinafter, embodiments of the crude steel cement concrete composition with improved durability and strength according to the present invention will be more specifically shown, and the present invention is not limited by the following embodiments.

≪ Example 1 >

18% by weight of crude steel cement based binder, 42% by weight of fine aggregate, and 34% by weight of coarse aggregate were forced into a mixer and stirred. Then, 4% by weight of water and 2% by weight of a functional admixture were further mixed, Durability and strength of the cementitious cement concrete composition were improved.

In this case, the cementitious bonding material is steel powder also has 5,000 ~ 8,500cm ² / g of micro-cement 50% by weight of calcium aluminate 15% by weight, the powder also has 3,500 ~ 4,500cm ² / g and SiO ₂ content of 70% or more powder phyllite 10 wt% of slag powder, 5 wt% of gypsum, 2 wt% of sodium silicate, 1 wt% of calcium stearate, 1 wt% of aluminum oxide, 0.5 wt% of water reducing agent, and a delay of 15 wt% and a powdery degree of 4000 to 7000 cm & 0.5% by weight were mixed and used. At this time, the water reducing agent was a naphthalene water reducing agent and the retarding agent was a citric acid type retarding agent.

The functional admixture may be selected from the group consisting of 93.5 weight percent styrene-butadiene, 2 weight percent styrene-vinyl acetate, 1 weight percent acrylonitrile-vinylidene chloride polymer, 1 weight percent polyvinyl butylal, 1 weight percent hydroxyethylcellulose, 0.5% by weight of styrene, 0.5% by weight of methyl methacrylate butadiene, 0.3% by weight of a water reducing agent and 0.2% by weight of an antifoaming agent. At this time, the water reducing agent used was a naphthalene based water reducing agent, and the defoaming agent was a silicone based defoaming agent.

≪ Example 2 >

18% by weight of crude steel cement based binder, 42% by weight of fine aggregate, and 34% by weight of coarse aggregate were forced into a mixer and stirred. Then, 4% by weight of water and 2% by weight of a functional admixture were further mixed, Durability and strength of the cementitious cement concrete composition were improved.

In this case, the cementitious bonding material is steel powder also has 5,000 ~ 8,500cm ² / g of micro-cement 50% by weight of calcium aluminate 15% by weight, the powder also has 3,500 ~ 4,500cm ² / g and SiO ₂ content of 70% or more powder phyllite 10 wt% of slag powder, 5 wt% of gypsum, 2 wt% of sodium silicate, 1 wt% of calcium stearate, 1 wt% of aluminum oxide, 0.5 wt% of water reducing agent, and a delay of 15 wt% and a powdery degree of 4000 to 7000 cm & 0.5% by weight were mixed and used. At this time, the water reducing agent was a naphthalene water reducing agent and the retarding agent was a citric acid type retarding agent.

The functional admixture was prepared by mixing 88.5% by weight of styrene-butadiene, 4% by weight of styrene-vinyl acetate, 2% by weight of acrylonitrile-vinylidene chloride polymer, 2% by weight of polyvinylbutylalcohol, 2% by weight of hydroxyethylcellulose, 0.5% by weight of styrene, 0.5% by weight of methyl methacrylate butadiene, 0.3% by weight of a water reducing agent and 0.2% by weight of an antifoaming agent. At this time, the water reducing agent used was a naphthalene based water reducing agent, and the defoaming agent was a silicone based defoaming agent.

≪ Example 3 >

18% by weight of crude steel cement based binder, 42% by weight of fine aggregate, and 34% by weight of coarse aggregate were forced into a mixer and stirred. Then, 4% by weight of water and 2% by weight of a functional admixture were further mixed, Durability and strength of the cementitious cement concrete composition were improved.

In this case, the cementitious bonding material is steel powder also has 5,000 ~ 8,500cm ² / g of micro-cement 50% by weight of calcium aluminate 15% by weight, the powder also has 3,500 ~ 4,500cm ² / g and SiO ₂ content of 70% or more powder phyllite 10 wt% of slag powder, 5 wt% of gypsum, 2 wt% of sodium silicate, 1 wt% of calcium stearate, 1 wt% of aluminum oxide, 0.5 wt% of water reducing agent, and a delay of 15 wt% and a powdery degree of 4000 to 7000 cm & 0.5% by weight were mixed and used. At this time, the water reducing agent was a naphthalene water reducing agent and the retarding agent was a citric acid type retarding agent.

The functional admixture was prepared by mixing 83.5 wt% of styrene-butadiene, 6 wt% of styrene-vinyl acetate, 3 wt% of acrylonitrile-vinylidene chloride polymer, 3 wt% of polyvinyl butylal, 3 wt% of hydroxyethylcellulose, 0.5% by weight of styrene, 0.5% by weight of methyl methacrylate butadiene, 0.3% by weight of a water reducing agent and 0.2% by weight of an antifoaming agent. At this time, the water reducing agent used was a naphthalene based water reducing agent, and the defoaming agent was a silicone based defoaming agent.

Comparative Examples that can be compared with the embodiments of the present invention are shown in order to more easily grasp the characteristics of the first to third embodiments. Comparative Examples 1 and 2 to be described later are generally referred to as common Portland Cement concrete composition and polymer cement concrete composition.

≪ Comparative Example 1 &

18 wt% of Portland cement, 42 wt% of fine aggregate, 34 wt% of coarse aggregate and 6 wt% of water were forcibly introduced into a mixer and stirred to prepare a usual cement concrete composition.

≪ Comparative Example 2 &

18 wt% of ordinary Portland cement, 42 wt% of fine aggregate, and 34 wt% of coarse aggregate were forced into a mixer and stirred. Then, 4 wt% of water and 2 wt% of styrene-butadiene were further mixed and stirred for 2 minutes, A composition was prepared.

The following test examples show experimental results comparing the characteristics of the examples of the present invention with those of the comparative example 1 and the comparative example 2 in order to more easily grasp the characteristics of the examples 1 to 3 according to the present invention.

≪ Test Example 1 >

The crude steel cement concrete composition with self-healing property, durability and strength improved according to Examples 1 to 3 and the concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were subjected to a slump test according to the method defined in KS F 2402 (Degree of kneading). The slump test is to test the quality of the dough such as the flue and viscosity of the concrete. The larger the value, the better the workability in putting the concrete.

Table 1 below shows the change in slump over time.

As shown in Table 1, the crude steel cement concrete composition prepared according to Examples 1 to 3 had better workability than the cement concrete compositions prepared according to Comparative Examples 1 and 2, The crude steel cement concrete composition thus produced is excellent in workability because the change in slump is not large even after a lapse of time.

≪ Test Example 2 &

The crude steel cement concrete composition with self-healing property, durability and strength improved according to Examples 1 to 3 and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were compacted according to the method defined in KS F 2405 The result of the strength test is shown.

Table 2 below shows changes in compressive strength with time.

As shown in Table 2, the crude steel cement concrete compositions prepared according to Examples 1 to 3 had significantly higher compressive strengths than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

≪ Test Example 3 >

The cement concrete composition prepared according to Examples 1 to 3 and the self-healing property, durability and strength improved and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were subjected to the flexural strength As shown in FIG.

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

As shown in Table 3, the crude steel cement concrete compositions prepared according to Examples 1 to 3 had significantly higher bending strengths than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

<Test Example 4>

The crude steel cement concrete composition prepared according to the above Examples 1 to 3 with improved self-healing property, durability and strength and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were prepared according to the method defined in KS F 2762 The adhesive strength was measured and the results are shown in Table 4.

As shown in Table 4, the crude steel cement concrete compositions prepared according to Examples 1 to 3 had significantly higher adhesive strength than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

&Lt; Test Example 5 >

The crude steel cement concrete composition with self-healing property, durability and strength improved according to Examples 1 to 3 and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were measured according to the method defined in KS F 2476, Are shown in Table 5. &lt; tb &gt; &lt; TABLE &gt; If the water absorption rate is high, if the impurities or water penetrate into 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.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Absorption Rate (%) 0.85 0.6 0.45 2.4 1.0

As shown in Table 5, the crude steel cement concrete compositions prepared according to Examples 1 to 3 had a lower water absorption rate than the cement concrete compositions prepared according to Comparative Examples 1 and 2.

&Lt; Test Example 6 >

The crude steel cement concrete composition prepared according to Examples 1 to 3 with improved self-healing property, durability and strength and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were tested for KS F 2424 ), And the results are shown in Table 6. &lt; tb &gt; &lt; TABLE &gt;

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Length change rate (%) 0.03 0.03 0.02 0.14 0.09

As shown in Table 6, the crude steel cement concrete composition prepared according to Examples 1 to 3 had shrinkage reduction effect due to reduced drying shrinkage as compared with the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 I could confirm.

&Lt; Test Example 7 >

The cement concrete composition prepared according to Examples 1 to 3 and the self-healing property, durability and strength improved and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were frozen according to the method defined in KS F 2456 The measurement results of the fusion resistance test are 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 7 shows the durability indexes of the respective examples and comparative examples according to the freeze-thaw resistance test.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Durability index 90 92 93 54 88

As shown in Table 7, the durability of the crude steel cement concrete composition prepared according to Examples 1 to 3 was higher than that of the cement concrete compositions prepared according to Comparative Example 1 and Comparative Example 2, Able to know.

<Test Example 8>

The crude steel cement concrete composition with self-healing property, durability and strength improved according to Examples 1 to 3 and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were tested by KS F 2476, The results are shown in Table 8 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Chloride ion bed depth (mm) 0.5 0.4 0.3 2.0 0.9

As shown in Table 8, the crude steel cement concrete compositions prepared according to Examples 1 to 3 had a lower chloride ion penetration depth than the cement concrete compositions prepared according to Comparative Examples 1 and 2, Was high.

&Lt; Test Example 9 >

The crude steel cement concrete composition with self-healing property, durability and strength improved according to Examples 1 to 3 and the cement concrete composition prepared according to Comparative Example 1 and Comparative Example 2 were tested by KS F 2476, The results are shown in Table 9 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Neutralization depth (mm) 0.4 0.3 0.2 1.8 0.7

As shown in Table 9, the crude steel cement concrete compositions prepared according to Examples 1 to 3 had a lower neutralization depth than the cement concrete compositions prepared according to Comparative Example 1 and Comparative Example 2, .

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.

According to the present invention, by using a functional admixture and a crude steel-cement based binder, workability of concrete can be improved, and strength of concrete, particularly tensile strength and adhesion strength, can be improved and durability can be greatly improved. In addition, by using activated silica, insoluble calcium hydroxide is produced to prevent bleaching and neutralization. In addition, since the hydration of the cement and the densification of the structure are promoted, the concrete can be formed, And the self-healing performance can be exerted.

Claims (7)

(1), wherein the cementitious aggregate comprises 3 to 35% by weight of crude steel cementitious binder, 20 to 75% by weight of fine aggregate, 20 to 70% by weight of coarse aggregate, 0.1 to 20% by weight of water and 0.01 to 15%
Wherein the crude steel cement based binder comprises 15 to 80 wt% of microcement having a powder degree of 5,000 to 8,500 cm ² / g, 1 to 45 wt% of calcium aluminate, a powdery degree of 3,500 to 4,500 cm ² / g, a SiO ₂ content of 70% 1 to 20% by weight of gypsum powder, 0.1 to 15% by weight of sodium silicate, 0.01 to 10% by weight of calcium stearate, 1 to 30% 0.01 to 10% by weight of aluminum oxide, 0.1 to 30% by weight of magnesium sulfoaluminate, and 0.01 to 5% by weight of titanium oxide,
Wherein the functional admixture comprises from 45 to 98% by weight of styrene-butadiene, from 1 to 30% by weight of styrene-vinyl acetate, from 0.1 to 20% by weight of acrylonitrile-vinylidene chloride polymer, from 0.1 to 20% by weight of polyvinybutyral, 0.01 to 15% by weight of hydroxyethylcellulose, and 0.01 to 10% by weight of butyl acrylate-styrene.
Wherein the self-healing property, the durability and the strength are improved.
delete delete delete delete A concrete structure maintenance method using the crude steel cement concrete composition having improved self-healing property, durability and strength according to claim 1,
(S1) chipping a portion where the concrete structure is deteriorated and the concrete is detached using a crusher and a water jet to remove impurities and deteriorated portions;
(S2) cleaning the removed portion with a vacuum suction vehicle;
(S3) In order to facilitate adhesion of the crude steel cement concrete composition to the concrete, improve the surface strength, to inhibit penetration of water and penetration of chlorine ions, and to improve water resistance, the functional admixture is applied to the cleaned area, Blooming with the polymer-cement mortar mixed with the polymer-cement mortar;
(S4) restoring or reinforcing a section of the deteriorated portion by placing the crude steel cement concrete composition on the top of the blooming treated or coated with the functional admixture;
(S5) a step of performing a tinning for increasing the friction on the poured crude steel cement concrete composition; And
(S6) a step of coating the top of the crude steel cement concrete composition with the coating-forming curing agent or surface penetration protection agent
A method for maintenance of a concrete structure using the self-healing property, durability and strength of a crude steel cement concrete composition.
The method according to claim 6,
Further comprising the step of removing the deteriorated portion to the lower portion of the reinforcing bar and rust-proofing the exposed reinforcing bar before the step of applying the functional admixture or performing the blooming treatment after the cleaning step. Maintenance method of concrete structure using crude steel cement concrete composition.