KR100820276B1 - Composition compound for repairing concrete structure, manufacturing method thereof and repairing method of concrete structure using the composition compound - Google Patents

Abstract

A composition for repairing a concrete structure is provided to exhibit excellent penetration and good characteristics such as water resistance, chemical resistance, and acid resistance when a concrete structure is repaired. A composition for repairing a concrete structure is manufactured by the steps of: obtaining an aqueous silica sol; charging the aqueous silica sol and organoalkoxy silane into a reactor, and obtaining a partially hydrophobic-treated aqueous silica sol having hydrophilicity and hydrophobicity by performing hydrolytic polymerization to make the silica particles partially hydrophobic; charging boric acid(B2O3) into the reactor to promote vitrification of the composition; and stirring alkali silicate in the reactor containing the partially hydrophobic-treated aqueous silica sol. Further, the alkali silicate is at least one selected from potassium silicate and lithium silicate.

Description

Composition compound for repairing concrete structure, manufacturing method method and repairing method of concrete structure using the composition compound

The present invention relates to a composition for a concrete repair material, a method for manufacturing the same, and a method for repairing a concrete structure, and more particularly, a composition for a concrete repair material and a method for manufacturing the same, including a mixture of a partial hydrophobized aqueous silica sol and an alkali silicate, and concrete repair It relates to a repair method for a concrete structure using the ash composition.

Cracks in concrete structures can cause fatal defects due to poor water resistance, corrosion of reinforcing steel, reduced durability, and reduced strength. Concrete cracks are often caused by various factors such as salt, external environment such as deterioration, design load, material properties such as plastic shrinkage or dry shrinkage, mixing conditions, and construction factors. If a crack occurs in a concrete structure due to such factors, the concrete structure may not bear the load and may collapse. The cracked concrete structure needs to be repaired to restore waterproofness, durability, or to consider the stability of the structure, aesthetics, and the like. In order to repair the cracked part, penetration type repair material using injection method is generally used.

The penetration type repair materials generally used both at home and abroad are composed of alkali silicates. Such alkali-based silicates form calcium silicates by rapidly reacting with calcium ions, the main component of concrete, even though the surface tension is small. These calcium silicates are insoluble and chemically very stable oxides to protect the surface of the concrete, but the penetration is only a few mm has a problem that can not penetrate the interior of the concrete has a disadvantage that is difficult to recover the performance of the concrete structure.

In addition, the concrete water-repellent material that is widely used at home and abroad serves to block the penetration of water by generating a water-repellent power by reacting after the water-repellent material is penetrated into the concrete structure to react with the concrete. When the hydraulic pressure is large, as in the exponential underground structure, it is difficult to apply due to the limitation of water repellency, and it is decomposed by heat and ultraviolet rays, and thus does not exhibit long-term performance. Particularly, in case of the conventional penetration type water repellent material, since the concrete surface forms a strong lipophilic layer, the secondary coating on the concrete surface has a disadvantage of deterioration in adhesiveness, weak water resistance, and decomposes when exposed to ultraviolet rays. have. In addition, there is a problem such as degradation of the chemical performance is degraded when exposed to sulfuric acid and hydrochloric acid, and not exhibit its function.

Meanwhile, Korean Patent Registration No. 227922 discloses an emulsion in which the alkylalkoxy silane has a particle size of 2-10 μm and a concentration of 5-70 wt%. This has a problem that the adhesion strength is significantly lowered when adhered to other adherends due to the water repellency of the surface.When the concentration of the alkyl alkoxy silane is less than 70%, the concentration of water is relatively increased. It has a problem such as poor performance and easy gelation.

In addition, in the case of using an alkyl alkoxy silane-based water-repellent material containing an organic solvent, it is possible to replace a part of the silane with an organic solvent, so that the price is low and the adhesion to other adherends is improved, but water pressure works like an index underground structure. The structure is less resistant, its use is limited and additional waterproofing is required.

In addition, the concrete waterproofing material comprising an alkylalkoxy silane and a high molecular compound relates to an alkyl alkoxy silane emulsion cream and a concrete waterproofing material comprising the same, which is a creamy concrete waterproofing material manufactured by mixing an emulsifier in an alkyl alkoxy silane to use water as a solvent. . This is obtained by the water repellency of n-octylethoxy silane, but n-octylethoxy silane is easily decomposed by heat and ultraviolet rays, and can be gradually changed to hydrophilic with time and eluted. The problem is that it is only about 3-5 years. In addition, since the water repellency of the concrete water repellent is applied to the mechanism of suppressing the ingress of water, it is difficult to apply to the structure of the hydraulic pressure, such as exponential underground structure.

The technical problem to be achieved by the present invention is to provide a composition for repairing concrete having excellent penetration properties and excellent properties such as water resistance, chemical resistance, acid resistance, durability, flame resistance and strength when repairing concrete structures.

Another technical problem to be achieved by the present invention is to provide a method for producing a composition for repairing concrete having excellent penetration properties and excellent properties such as water resistance, chemical resistance, acid resistance, durability, flame resistance and strength when repairing concrete structures.

Another technical problem to be achieved by the present invention is to repair the concrete structure by using a composition for concrete refining material including partially hydrophobized aqueous silica sol and alkali silicate, and has excellent penetration, water resistance, chemical resistance, acid resistance, durability, flame resistance and The present invention provides a repair method for concrete structures exhibiting excellent properties in strength and the like.

The present invention provides a composition for repairing concrete structures, wherein the composition for concrete repairs comprises partially hydrophobized aqueous silica sol and alkali silicate having partially hydrophobized hydrophilicity and hydrophobicity.

The composition may contain 5 to 60% by weight of partially hydrophobized aqueous silica sol and 0.1 to 60% by weight of alkali silicate.

It may further contain boric acid (B ₂ O ₃ ) to promote the vitrification of the composition. The composition may contain 0.1-10% by weight of boric acid (B ₂ O ₃ ).

The partially hydrophobized aqueous silica sol has a structure in which an aqueous silica sol and an organoalkoxy silane having the following molecular formula are hydrolyzed and partially hydrolyzed to the particle surface of the monodisperse silica sol.

[Molecular formula]

R ₁ Si (OR ₂ ) ₃ , wherein R ₁ is an organic group having 1 to 8 carbon atoms, and R ₂ is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms.

The partially hydrophobized aqueous silica sol has a particulate shape in the form of a monodisperse, 10-30 nm in size.

The alkali silicate may be at least one selected from potassium silicate and lithium silicate.

In addition, the present invention, in the method for producing a composition for repairing a concrete structure, the step of obtaining an aqueous silica sol, the aqueous silica sol and the organo alkoxy silane is added to the reactor hydrolyzed polymerization reaction to silica particles It provides a method of producing a composition for concrete repair materials comprising the step of obtaining a partially hydrophobized aqueous silica sol partially hydrophobized to have hydrophilicity and hydrophobicity and mixing and stirring the alkali silicate in the partially hydrophobized aqueous silica sol.

The aqueous silica sol can be obtained by using water ion exchange method or by hydrolyzing alkoxy silane.

The said hydrolysis can use alcohol or water as a solvent, and can use an acid or an alkali type catalyst as a catalyst.

5 to 60% by weight of the aqueous silica sol may be added to the reactor, and 0.1 to 60% by weight of the alkali silicate may be added.

In order to promote vitrification of the composition, the method may further include adding 0.1 to 10% by weight of boric acid (B ₂ O ₃ ) to the reactor.

Obtaining the partially hydrophobized aqueous silica sol uses a method in which the aqueous silica sol and the organo alkoxy silane having the following molecular formula are hydrolyzed to partially cover the hydrolyzate on the particle surface of the monodisperse silica sol. .

[Molecular formula]

R ₁ Si (OR ₂ ) ₃ , wherein R ₁ is an organic group having 1 to 8 carbon atoms, and R ₂ is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms.

The partially hydrophobized aqueous silica sol has a particulate form in the form of a monodisperse, 10-30 nm in size.

The alkali silicate may be at least one selected from potassium silicate and lithium silicate.

In addition, the present invention, the step of spraying water to the concrete structure to be repaired, the step of spraying the composition for the concrete repair material, including the aqueous silica sol and alkali silicate partially hydrotreated to the concrete structure of the part to be repaired and the concrete repair After spraying the ash composition provides a repair method for the concrete structure using a concrete repair material composition comprising the step of watering the concrete structure of the portion to be repaired.

In addition, the present invention, the step of removing the impurities and deterioration site by chipping (Chipping) the site where the concrete structure is deteriorated due to deterioration of the concrete structure, the step of applying a primer to the concrete deterioration site, the composition for concrete repair materials It provides a repair method for a concrete structure using a concrete repair material composition comprising the step of applying a cross section of the deteriorated site with the mortar mixed with the mortar is applied.

The mortar may contain 3 to 8% by weight of the composition for concrete repair materials.

The primer may be at least one selected from acrylic, ethyl vinyl acetate (EVA), and styrene butadiene rubber (SBR) to facilitate the concrete repair material to be fixed to the concrete structure.

According to the present invention, when repairing a concrete structure, it is possible to obtain a composition for repairing concrete having excellent penetration and excellent properties such as water resistance, chemical resistance, acid resistance, durability, flame resistance and strength.

In the case of repairing exposed concrete structures such as bridges and exponential underground structures using the composition for concrete repair materials according to the present invention, the composition for concrete repair materials penetrates deeply into the concrete structure and undergoes fine sol-gelation by hydrolysis and pozzolanic reactions. Vitrified to fill fine pores. Therefore, the composition for concrete repair materials is integrated by filling the cracks, thereby forming a barrier film having improved strength up to the reinforcement depth of the reinforcing bar. Therefore, in addition to the water blocking effect, it shows an excellent effect of neutralization, water resistance, weather resistance and freeze-thaw resistance by chloride or carbon dioxide.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen.

The penetration repair composition according to a preferred embodiment of the present invention includes a partially hydrophobized aqueous silica sol and an alkali silicate.

First, a method of preparing a partially hydrotreated aqueous silica sol is described.

The aqueous silica sol can be prepared by ion exchange method of conventional water glass or by hydrolysis of alkoxy silane. The aqueous silica sol is a finely dispersed particle having a particle size of about 10-30 nm.

Aqueous silica sol can be obtained by the well-known ion exchange method generally using water glass. Water glass refers to an aqueous alkali silicate solution obtained by melting silicon dioxide and alkali.

In addition, hydrolysis of alkoxy silanes represented by tetra ethoxy silane (Si (OC ₂ H ₅ ) ₄ ) or tetra methoxy silane (Si (OCH ₃ ) ₄ ), etc. It is also possible to obtain an aqueous silica sol. The hydrolysis may use a solvent and a catalyst, alcohols such as ethanol or water may be used as the solvent, and an acid or alkali catalyst may be used as the catalyst. As the acid catalyst, hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ COOH), etc. may be used, and as alkali catalysts, ammonium hydroxide (NH ₄ OH) and sodium hydroxide (NaOH), potassium hydroxide (KOH), organic amines and the like can be used. At this time, the alkoxy silane is added about 5 to 60% by weight, preferably 20 to 40% by weight. The solvent is added in about 30 to 40% by weight, the catalyst is added in about 0.1 to 10% by weight. The said hydrolysis reaction can be performed at normal temperature (for example, the temperature of about 15-25 degreeC).

Organo alkoxy silane (R ₁ Si (OR ₂ ) ₃ ) in aqueous silica sol To the hydrolysis reaction. Organo molecular formula R ₁ Si (OR _{2) 3} in R ₁ of the alkoxysilane is an organic group having 1 to 8, R ₂ represents an acyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 4 carbon atoms. The hydrolysis reaction may use a solvent and a catalyst, alcohols such as ethanol or water may be used as the solvent, and an acid or alkali catalyst may be used as the catalyst. As the acid catalyst, hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ COOH), etc. may be used, and as alkali catalysts, ammonium hydroxide (NH ₄ OH) and sodium hydroxide (NaOH), potassium hydroxide (KOH), organic amines and the like can be used. At this time, the aqueous silica sol is added about 5 to 60% by weight, preferably 20 to 40% by weight. The organoalkoxy silane is added in an amount of about 1 to 50% by weight, preferably about 5 to 20% by weight. The solvent is added in about 30 to 40% by weight, the catalyst is added in about 0.1 to 10% by weight. The said hydrolysis reaction can be performed at the temperature of about 20-90 degreeC.

By hydrolysis, the hydrolyzate is formed on the surface of the particles of the monodisperse silica sol and a polycondensation reaction can be performed to obtain a partially hydrophobic aqueous silica sol. Treatment of the organo alkoxy silane with the aqueous silica sol results in partial hydrophobization of the silica particles resulting in hydrophilic and hydrophobic properties.

R ₁ may be an organic date having a carbon of 1 to 8 carbon atoms in the molecular formula of the organo alkoxysilane _{(organo alkoxy silane, R 1 Si} (OR 2) 3) is used the surface of the particles of the aqueous silica sol to the part of hydrophobized . Examples of the organic group having 1 to 8 carbon atoms include an alkyl group such as methyl group, ethyl group, n-propyl group, and i-propyl group, other r-chloropropyl group, vinyl group, 3,3,3-trfluoropropyl group, r -Glycidoxypropyl group, r-methacryloxypropyl group, r-mercaprotopropyl group, phenyl group, 3,4-epoxycyclohexylethyl group, r-aminopropyl group, and the like.

In addition, R ₂ may be an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, n-propyl group, i-phorophil group, n-butyl group, sec-butyl group, tert-butyl Group, an acetyl group, and the like.

Specific examples of the organoalkoxy silane include methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, ethyltriethoxysilane, n-propyltriethoxysilane, i-propyltriethoxysilane and r-chloro Propyltrimethoxysilane, r-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, r-glycidoxypropyltrimeth Methoxysilane, r-methacryloxypropyltrimethoxysilane, r-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, r-aminopropyltrimethoxysilane, 3,4-epoxycyclohexylethyltrie Oxysilane, etc. are mentioned. The organoalkoxy silane can be mixed with 1 type, or 2 or more types, and the usage-amount is about 1-50 weight% of aqueous silica sol, Preferably it is about 5-20 weight%.

Subsequently, an alkali silicate (R ₂ O.SiO ₂ ) is added to the partially hydrotreated aqueous silica sol, followed by stirring for a predetermined time (eg, 4 to 24 hours) to prepare a penetration repair composition. It is preferable to perform the said stirring at the speed of about 100-200 rpm.

The alkali silicate (alkali silicate, R ₂ O.SiO ₂ ) may be used at least one selected from the group consisting of potassium silicate and lithium silicate.

Sodium silicate in alkali silicate is generally used because it forms insoluble calcium silicate by substitution with potassium ions when used as a water-retaining material in concrete, but in the present invention, in order to realize excellent water resistance Calcium silicate and lithium silicate having better water resistance than sodium silicate are used.

The use amount of these alkali silicates is 0.1-60 weight% with respect to the composition for penetration type repair materials, Preferably it is about 30-50 weight%.

In addition, in the composition for penetration type repair materials according to a preferred embodiment of the present invention, boric acid (B ₂ O ₃ ) is added to promote the vitrification of the composition and enhance the strength when the concrete repair material is treated to the concrete index structure. Boric acid (B ₂ O ₃₎ amount of is 0.1 to 10% by weight relative to the penetration-type damper compensation composition, and preferably from 0.2 to 5% by weight.

In the concrete repair composition comprising the partially hydrolyzed aqueous silica sol and alkali silicate prepared according to the preferred embodiment of the present invention, the silica particles are partially hydrophobized by treating the aqueous silica sol with an organoalkoxysilane. It develops hydrophilic and hydrophobic properties. When the concrete repair material is treated to repair the cracks of the concrete, not only the excellent hydrophobic property of the concrete index structure is exhibited by the partial hydrophobic nature of the silica sol, but also the rapid reaction with the concrete during the infiltration process suppresses the existing concrete. Compared with repairing materials, the penetration is greater and can be integrated with concrete structures The penetration depth can be increased and integrated with the concrete structure to provide an effective method for repairing the concrete structure.

Concrete repair material composed of a mixture of partially hydrophobized aqueous silica sol and alkali silicate according to the present invention has excellent water resistance, chemical resistance, acid resistance, durability, flame resistance, anti-neutralization and strength recovery, so that it can be used as concrete repair material for concrete structures. It is possible.

The present invention will be described with respect to the repair method of the concrete structure using the composition for the concrete repair material in order to prevent the strength degradation, deterioration prevention, waterproofing and repair of the concrete index structure.

First, water is sprayed on the concrete structure to be repaired. It is desirable to spray enough water so that water can penetrate to the cracked part inside the concrete structure. After the water is sprayed, after a predetermined time (for example, 4 to 12 hours), the water penetrates into the concrete structure by a capillary phenomenon.

After watering, after several hours (eg, 4-12 hours), the concrete structure is sprayed with a composition for concrete refinishments that includes partially hydrophobized aqueous silica sol and alkali silicate.

After spraying the composition for concrete refinish, water is sprayed on the concrete structure after several hours (eg, 12-24 hours).

The concrete repair material composition is sprayed on the concrete structure to be repaired due to cracks, etc. in the same way as above, and as time passes, the composition for concrete repair material is integrated with the concrete structure and is waterproof, durable, water resistant, chemical and acid resistant. Excellent properties such as flame resistance and strength recovery can be obtained.

Another example of a repair method for restoring the performance of concrete structures will be described.

As a repair method of a site where concrete structures are deteriorated due to deterioration of a concrete structure, impurities and deterioration sites are removed by chipping the deteriorated sites.

A dedicated primer is applied to the deteriorated area. The dedicated primer may be acryl, ethyl vinyl acetate (EVA), styrene butadiene rubber (SBR) and the like. The dedicated primer serves to facilitate the fixing of the composition for concrete repair material to the concrete structure.

The cross section of the deteriorated site is recovered by mortar incorporating (or impregnating) the composition for concrete refinish material consisting of a mixture of partially hydrophobized aqueous silica sol and alkali silicate. It is preferable to impregnate the composition for concrete repair materials about 3 to 8 weight% with respect to mortar.

The composition for concrete refinish which consists of a mixture of the partial hydrophobization aqueous silica sol and alkali silicate is apply | coated to the site | part to which mortar was apply | coated. The concrete repair material is sprayed on the concrete structure to be repaired in the same way as above, and after time passes, the concrete repair material composition is integrated with the concrete structure to provide waterproofness, durability, water resistance, chemical resistance, acid resistance, and flame resistance. And excellent properties such as strength recovery.

In the case of repairing exposed concrete structures such as bridges and exponential underground structures using the composition for concrete repair materials according to the present invention, the composition for concrete repair materials penetrates deeply into the concrete structure and undergoes fine sol-gelation by hydrolysis and pozzolanic reactions. Vitrified to fill fine pores. Therefore, the composition for concrete repair materials is integrated by filling the cracks, thereby forming a barrier film having improved strength up to the reinforcement depth of the reinforcing bar. Therefore, in addition to the water blocking effect, it shows an excellent effect of neutralization, water resistance, weather resistance and freeze-thaw resistance by chloride or carbon dioxide.

Hereinafter, the present invention will be described in more detail with reference to Examples.

<Example 1>

The water glass is ion exchanged to give an aqueous silica sol (solid content: 30 wt%, particle size: 10-20 nm, pH of sol: 3.5). Specifically, water glass (30% sodium silicate) was passed through an activated cation exchange resin to prepare a silicic acid solution, and the pH was calibrated to about alkali and aged at 80 ° C. for 12 hours to prepare an alkaline aqueous silica sol. After preparation, the resultant is passed through a cation exchange resin to obtain an aqueous silica sol (solid content: 30 wt%, particle size: 10-20 nm, pH of sol: 3.5).

3 kg of an aqueous silica sol was charged to a 15-l reactor, and 0.4 kg of r-glycidoxypropyltrimethoxysilane, a kind of organoalkoxy silane, was maintained at 20 ml / min using a metering pump while maintaining the reactor temperature at 80 ° C. The solution was added at a rate and subjected to partial hydrolysis polymerization at that temperature for 12 hours to form a partially hydrolyzed aqueous silica sol and cooled to room temperature. The cooling was performed by naturally cooling the partially hydrotreated aqueous silica sol at room temperature. The hydrolysis may use a solvent and a catalyst. Ethanol is used as a solvent, and hydrochloric acid (HCl), which is an acid catalyst, is used as a catalyst. The solvent is added about 35% by weight and the catalyst is added by about 1% by weight.

6 kg of water was added to the cooled reaction and stirred at a speed of about 150 rpm for 2 hours. Ethylenediamine was added to the reaction product at a rate of 50ml / min using a 300g metering pump to calibrate the pH of the reaction product to 10.5, and then a solution containing 3kg of potassium silicate was added and stirred at a speed of about 150rpm for 4 hours. .

While maintaining the temperature of this reaction at 50 ° C, 1.5 kg of B ₂ O ₃ was charged and reacted to prepare a composition for concrete repair materials, and cooled to room temperature. The cooling was carried out by a method of naturally cooling the composition for concrete repair materials at room temperature.

<Example 2>

The water glass is ion exchanged to give an aqueous silica sol (solid content: 30% by weight, particle size: 10-20 nm, pH of sol: 9.4). Specifically, water glass (30% sodium silicate) was passed through an activated cation exchange resin to prepare silicic acid (silicic acid solution), and the pH was calibrated with about alkali and aged at 60 ° C. for 24 hours to give an aqueous silica sol ( Solid content: 30% by weight, particle size: 10-20 nm, pH of sol: 9.4).

3 kg of an aqueous silica sol was charged to a 15-l reactor, and 0.2 kg of r-aminopropyltrimethoxysilane, a type of organoalkoxy silane, was maintained at a rate of 20 ml / min using a metering pump while maintaining the reactor temperature at 80 ° C. The mixture was partially hydrolyzed for 12 hours at that temperature to produce a partially hydrolyzed aqueous silica sol, and cooled to room temperature. The cooling was performed by naturally cooling the partially hydrotreated aqueous silica sol at room temperature. The hydrolysis may use a solvent and a catalyst. Ethanol is used as a solvent, and hydrochloric acid (HCl), which is an acid catalyst, is used as a catalyst. The solvent is added about 35% by weight and the catalyst is added by about 1% by weight.

3 kg of water was added to the cooled reaction and stirred at a speed of about 150 rpm for 2 hours. 4 kg of potassium silicate and 1 kg of lithium silicate were added to the reaction mixture, followed by stirring at a speed of about 150 rpm for 4 hours.

While maintaining the temperature of this reaction at 50 ° C, 1 kg of B ₂ O ₃ was added and reacted to prepare a composition for concrete repair materials, and cooled to room temperature. The cooling was carried out by a method of naturally cooling the composition for concrete repair materials at room temperature.

<Example 3>

The tetraethoxy silane is hydrolyzed to give an aqueous silica sol (solid content: 20 wt%, particle size: 10-20 nm, pH of sol: 10.5). For the hydrolysis, a solvent and a catalyst may be used. Ethanol is used as a solvent, and caustic soda (NaOH), which is an alkaline catalyst, is used as a catalyst. The solvent is added about 35% by weight and the catalyst is added by 5% by weight. The hydrolysis reaction is carried out at room temperature.

3 kg of an aqueous silica sol was charged to a 10-l reactor, and 0.1 kg of r-aminopropyltrimethoxysilane, a type of organoalkoxy silane, was maintained at a rate of 20 ml / min using a metering pump while maintaining the reactor temperature at 80 ° C. It is charged, and partially hydrolyzed for 12 hours at that temperature to form a partially hydrolyzed aqueous silica sol and cooled to room temperature. The cooling was performed by naturally cooling the partially hydrotreated aqueous silica sol at room temperature. For the hydrolysis, a solvent and a catalyst may be used. Ethanol is used as a solvent, and caustic soda (NaOH), which is an alkaline catalyst, is used as a catalyst. The solvent is added about 35% by weight and the catalyst is added by 5% by weight.

2 kg of water is added to the cooled reaction and stirred at a speed of about 150 rpm for 2 hours. 4 kg of potassium silicate and 1 kg of lithium silicate were added to the reaction mixture, followed by stirring at a speed of about 150 rpm for 4 hours.

While maintaining the temperature of this reaction at 50 ° C, 800 g of B ₂ O ₃ was added and reacted to prepare a composition for concrete repair materials, and cooled to room temperature. The cooling was carried out by a method of naturally cooling the composition for concrete repair materials at room temperature.

The present invention is described in more detail with reference to the following experimental examples, which are not intended to limit the present invention.

Experimental Example 1 Preparation of Test Specimen

After applying the composition for the concrete repair material prepared in Examples 1 to 3 in three concrete test specimens of 150mm × 40mm in diameter 20g of the concrete repair material for 20 days, 20 ± 2 ℃, relative humidity 65 ± 5% (RH Were cured in a constant temperature and humidity room.

Penetration depth is divided into two according to KS F 4930 (liquid absorption inhibitor for concrete surface coating), spray water on the cross section, and differentiate according to the thickness of the part where water penetrated and the surface color difference of the part where water does not penetrate The thickness to be measured was measured. The measurement measured the penetration depth of 3 places about three test bodies, and the average value was shown as penetration depth, and the result is shown in Table 2.

In addition, the water absorption performance is 14 days after applying the 20g composition to five concrete specimens of 150mm × 40mm after waterproofing the sides of the test specimen with epoxy resin according to KS F 2609 (Method of measuring the water absorption coefficient of building materials). Were cured in a constant temperature and humidity room of 20 ± 2 ° C. and 65 ± 5% (RH) relative humidity. Each weight was measured in units of 0.1 g and the water was deposited at a depth of about 2-10 mm in water of about 20 ° C., and then the weights of 10 minutes, 30 minutes, 1 hour, 6 hours, and 24 hours were measured. When the weight was measured, the test body was taken out and the water on the surface was removed. Water absorption coefficient was calculated by calculating the slope of the solid line of the measured value and the results are shown in Table 2.

The concrete used in the experiment was prepared in the mixing ratio shown in Table 1 to produce the specimen under the same mixing conditions.

Coarse aggregate maximum dimension (mm) Slump (cm) Air volume (%) Water-cement ratio (%) Fine aggregate fraction (%) Unit weight (㎏ / ㎥) water cement Fine aggregate Coarse aggregate Admixture 16.0 10 5.0 50.0 35.0 166 332 616 1180 0.83

Test Items Example 1 Example 2 Example 3 Penetration depth (mm) 32.2 32.0 32.0 Water absorption coefficient ratio 0.08 0.08 0.08

Experimental Example 2 Strength Test

The concrete repair material composition prepared according to the present invention was impregnated in the concrete produced in the compounding ratio shown in Table 1 and cured in a constant temperature and humidity room of 20 ± 2 ℃, relative humidity 65 ± 5% (RH) for 14 days.

In order to compare the mechanical properties of the coated and uncoated specimens prepared in Example, the compressive strength test by KS F 2405 (compressive strength test method of concrete) was performed, and the results are shown in Table 3 below. Shown in

In addition, the flexural strength test was carried out by KS F 2408 (conductivity test method of concrete), tensile strength was measured by KS F 2423 (conductivity test method of concrete), and the results are shown in Table 3 below.

Test Items Comparative Experiment for Example 1 Comparative Experiment for Example 2 Comparative Experiment for Example 3 Impregnation (Example 1) No impregnation (comparative example) Impregnation (Example 2) No impregnation (comparative example) Impregnation (Example 3) No impregnation (comparative example) Strength (kgf / ㎠) warp 90 45 88 45 85 45 compression 385 305 378 305 370 305 Seal 55 25 53 25 53 25

In Table 3, impregnation is a case where the composition for concrete repair material prepared according to the above-described embodiment is applied to the concrete test body, and non-impregnation refers to a case where the composition for concrete repair material is not applied to the concrete test body as a comparative example of the embodiment.

As shown in Table 3, the bending, compression and tensile strength of the concrete coated with the composition for concrete repair prepared according to the preferred embodiment of the present invention was higher than the one not applied. It can be confirmed that the impregnated with the composition for concrete repair materials prepared according to the preferred embodiment of the present invention is excellent in strength.

Experimental Example 3 Neutralization Depth and Chloride Ion Penetration Depth

The concrete repair composition prepared according to the present invention was impregnated in the concrete produced in the compounding ratio shown in Table 1 and cured in a constant temperature and humidity room of 20 ± 2 ℃, relative humidity 65 ± 5% (RH) for 14 days.

In order to compare the durability characteristics of the coated and uncoated test specimens prepared in Example, the test specimens were accelerated for 14 days according to JIS A 1171 (Polymer cement mortar test method) [30 ° C, 60% (RH), CO ₂ concentration 5.0%], and the test body was divided into 2 parts, and 1% alcohol solution of phenolphthalein was sprayed on the cross section, and the neutralization depth was measured using the part which does not turn red as a neutralization part. The results are shown in Table 4.

In addition, the chloride ion penetration test was carried out by immersing the test body in a 2.5% sodium chloride aqueous solution at 20 ° C. for 7 days according to JIS A 1171, and then dividing the test body into two pieces, and spraying a 0.1% aqueous solution of sodium prolacrosene and 0.1 N silver acetate on the cross-section to fluoresce the fluorescent particles. Chloride ion permeation depth was measured using the part which emits chloride as the chloride ion (Cl ⁻ ) penetration part, and the results are shown in Table 4.

Test Items Comparative Experiment for Example 1 Comparative Experiment for Example 2 Comparative Experiment for Example 3 Impregnation (Example 1) No impregnation (comparative example) Impregnation (Example 2) No impregnation (comparative example) Impregnation (Example 3) No impregnation (comparative example) Neutralization Depth (mm) 0.1 6.2 0.15 6.2 0.18 6.2 Chloride ion penetration depth (mm) 0.15 7.8 0.18 7.8 0.2 7.8

In Table 4, impregnation is a case where the composition for concrete repair material prepared according to the above-described embodiment is applied to the concrete test body, and non-impregnation refers to a case where the composition for concrete repair material is not applied to the concrete test body as a comparative example of the embodiment.

As shown in Table 4, the neutralization depth and the chloride ion penetration depth of the concrete impregnated with the composition for concrete repair prepared according to the preferred embodiment of the present invention are 1/2 and less than that without impregnating the composition for concrete repair, respectively. One third lower. It can be confirmed that the impregnated with the composition for concrete repair materials prepared in the present invention is excellent in neutralization and salting.

Experimental Example 4 Water Resistance

In order to check whether the concrete repair material of the present invention is water-resistant, the water absorption of the coated and uncoated test specimens was measured using the method given in JIS A 1171 (Test Method of Polymer Cement Mortar), and the results are shown in Table 5 below. Indicated.

Test Items Comparative Experiment for Example 1 Comparative Experiment for Example 2 Comparative Experiment for Example 3 Impregnation (Example 1) No impregnation (comparative example) Impregnation (Example 2) No impregnation (comparative example) Impregnation (Example 3) No impregnation (comparative example) Water resistance, water absorption rate (%) 0.1 8.5 0.2 8.5 0.25 8.5

In Table 5, the impregnation is a case where the composition for concrete repair material prepared according to the above-described embodiment is applied to the concrete test body, and the non-impregnation refers to a case where the composition for concrete repair material is not applied to the concrete test body as a comparative example of the embodiment.

As shown in Table 5, the water resistance of the concrete impregnated with the composition for concrete repair material prepared according to the preferred embodiment of the present invention was about 1/5 lower than that without the impregnation for the concrete repair material. Impregnating the concrete repair material composition prepared according to the preferred embodiment of the present invention was confirmed to be excellent in water resistance.

Experimental Example 5 Weather Resistance

The accelerated weathering test was conducted by ASTM (Designation: G26 Nonmetallic Materials). The test apparatus is a Xenon-Arc Type water-cooled apparatus and belongs to Type A.

The test conditions were 40 ° C. and 60% RH, so that only 51 minutes of light was emitted, 9 minutes of light and water were sprayed, and one cycle was 60 minutes, and 2000 cycles were applied. Table 6 shows the weather resistance results of the coated and uncoated specimens.

Test Items Comparative Experiment for Example 1 Comparative Experiment for Example 2 Comparative Experiment for Example 3 Impregnation (Example 1) No impregnation (comparative example) Impregnation (Example 2) No impregnation (comparative example) Impregnation (Example 3) No impregnation (comparative example) Weather resistance No change Change No change Change No change Change

In Table 6, impregnation is a case where the composition for concrete repair material prepared according to the above-described embodiment is applied to the concrete test body, and non-impregnation refers to a case where the composition for concrete repair material is not applied to the concrete test body as a comparative example of the embodiment.

As shown in Table 6, as a result of the weather resistance test of the concrete impregnated with the composition for concrete repair material prepared according to the preferred embodiment of the present invention, there was no change in the surface, but the impregnated with the composition for concrete repair material Cracking and yellowing were observed.

Experimental Example 6 Freeze Melting Resistance

The freeze-thaw test was carried out on the freeze-thaw test specimens in accordance with KS F 2456 (Test method for the resistance of concrete to rapid freeze-thaw). Table 7 shows the results of freezing and thawing resistance of the coated and uncoated specimens.

Test Items Comparative Experiment for Example 1 Comparative Experiment for Example 2 Comparative Experiment for Example 3 Impregnation (Example 1) No impregnation (comparative example) Impregnation (Example 2) No impregnation (comparative example) Impregnation (Example 3) No impregnation (comparative example) Durability index 98 60 97 60 95 60

In Table 7, the impregnation is a case where the composition for concrete repair material prepared according to the above-described embodiment is applied to the concrete test body, and the non-impregnation refers to a case where the composition for concrete repair material is not applied to the concrete test body as a comparative example of the embodiment.

As shown in Table 7, as a result of the freeze-melt resistance test of the concrete impregnated with the composition for concrete repair material prepared according to the preferred embodiment of the present invention showed a much better result than the unimpregnated composition for concrete repair material . It was found that the composition for concrete repair materials according to the preferred embodiment of the present invention is excellent in freezing and thawing resistance.

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation by a person of ordinary skill in the art within the scope of the technical idea of this invention is carried out. This is possible.

Claims (18)

In a composition for repairing a concrete structure, Partially hydrophobized aqueous silica sol having partially hydrophobized silica particles to have hydrophilicity and hydrophobicity; Alkali silicates; And Concrete repair material comprising boric acid (B ₂ O ₃ ) to promote the vitrification of the composition. The composition according to claim 1, wherein the composition contains 5 to 60% by weight of partially hydrophobized aqueous silica sol and 0.1 to 60% by weight of alkali silicate. delete The composition for concrete repair materials according to claim 1, wherein the composition contains 0.1 to 10 wt% of boric acid (B ₂ O ₃ ). The partially hydrophobized aqueous silica sol of claim 1, wherein An aqueous silica sol and a organo alkoxy silane having the following molecular formula are hydrolyzed and have a structure in which the hydrolyzate is partially covered on the particle surface of the monodisperse silica sol. [Molecular formula] R ₁ Si (OR ₂ ) ₃ , wherein R ₁ is an organic group having 1 to 8 carbon atoms, and R ₂ is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms. The partially hydrophobized aqueous silica sol of claim 1, wherein The composition for concrete repair materials, characterized in that it has a particulate form of a monodisperse form of 10 to 30nm size. The method of claim 1, wherein the alkali silicate, The composition for concrete repair materials, characterized in that at least one selected from potassium silicate and lithium silicate. In the method of producing a composition for repairing a concrete structure, Obtaining an aqueous silica sol; Adding the aqueous silica sol and the organo alkoxy silane to a reactor to hydrolyze and polymerize to obtain a partially hydrophobized aqueous silica sol having hydrophilicity and hydrophobicity by partially hydrophobizing the silica particles; Introducing boric acid (B ₂ O ₃ ) into the reactor to promote vitrification of the composition; And A method for producing a composition for concrete repair materials comprising mixing and stirring an alkali silicate in a reactor in which a partially hydrophobized aqueous silica sol is obtained. The method of claim 8, wherein the aqueous silica sol, A method for producing a composition for concrete repair materials, characterized in that water glass is obtained by ion exchange or by hydrolysis of alkoxy silane. 10. The method of claim 8, wherein the aqueous silica sol and alkali silicate is added to the reactor so that the composition contains 5 to 60% by weight of the aqueous silica sol and 0.1 to 60% by weight of the alkali silicate. Method of Preparation of the Composition. The method of claim 8, wherein boric acid (B ₂ O ₃ ) is added to the reactor so that 0.1 to 10% by weight of boric acid (B ₂ O ₃ ) is contained in the composition. . The method of claim 8 wherein the step of obtaining a partially hydrophobized aqueous silica sol comprises An aqueous silica sol and an organoalkoxy silane having the following molecular formula are hydrolyzed to partially cover the hydrolyzate on the particle surface of the monodisperse silica sol. [Molecular formula] R ₁ Si (OR ₂ ) ₃ , wherein R ₁ is an organic group having 1 to 8 carbon atoms, and R ₂ is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms. 9. The partially hydrophobized aqueous silica sol of claim 8, A method for producing a composition for concrete repair materials, characterized in that it has a particulate form of a monodisperse form of 10 to 30nm size. The method of claim 8, wherein the alkali silicate, Method for producing a composition for concrete repair materials, characterized in that at least one selected from potassium silicate and lithium silicate. Watering the concrete structure to be repaired; Spraying the concrete repair material composition according to any one of claims 1, 2, and 4 to 7, including partially hydrolyzed aqueous silica sol and alkali silicate, on the concrete structure of the part to be repaired. ; And After spraying the composition for the concrete repair material, the composition for the concrete repair material according to any one of claims 1, 2, 4 to 7, including spraying water on the concrete structure of the portion to be repaired. Repair method of concrete structure. Deteriorating the concrete structure and chipping the site where the concrete is dropped to remove impurities and the deterioration site; Applying a primer to the concrete deteriorated site; Applying a cross section of a site deteriorated with a mortar incorporating the composition for concrete repair materials according to any one of claims 1, 2 and 4; And Claim 1, 2, 4 comprising the step of applying the composition for the concrete repair material according to any one of claims 1, 2, 4 to 7 to the site where the mortar is applied. The repair method of the concrete structure using the composition for concrete repair materials in any one of Claims 7-7. The method for repairing a concrete structure according to claim 16, wherein the mortar contains 3 to 8% by weight of the composition of any one of claims 1, 2, and 4-7. 17. The method of claim 16, wherein the primer is at least any one selected from acrylic, ethyl vinyl acetate (EVA) and styrene butadiene rubber (SBR) to facilitate the composition for fixing the concrete to the concrete structure The repair method of the concrete structure using the composition for concrete repair materials in any one of Claims 1, 2, 4 to 7 characterized by the above-mentioned.