KR102337117B1 - Shrinkage-reducing type polymer modified quick-hardening cement concrete composite and overlay pavement method for concrete using the same - Google Patents

Abstract

The present invention relates to a shrinkage-reducing polymer modified ultra-fast hardening cement concrete composition which comprises 5 to 45 wt% of a shrinkage-reducing strength developer, 10 to 75 wt% of fine aggregate, 7 to 65 wt% of coarse aggregate, 0.01 to 25 wt% of a polymer modifier, and 0.1 to 30 wt% of water. The shrinkage-reducing strength developer includes 100 parts by weight of high early strength Portland cement, 20 to 40 parts by weight of calcium sulfoaluminate, 1 to 20 parts by weight of tin oxide, 1 to 20 parts by weight of blast furnace slag, 1 to 20 parts by weight of zinc carbonate, 0.1 to 10 parts by weight of magnesium oxide, 0.1 to 10 parts by weight of sericite, and 0.1 to 10 parts by weight of calcium sulfate. The polymer modifier includes 100 parts by weight of a polymethyl methacrylate-(adamantyl)acrylate copolymer, 20 to 50 parts by weight of a styrene-butadiene-styrene copolymer, 10 to 30 parts by weight of N,N-dimethyl acrylamide, 0.1 to 10 parts by weight of phloretin sulfonate represented by chemical formula 1, and 0.1 to 10 parts by weight of polyrotaxane. According to the present invention, the shrinkage-reducing polymer modified ultra-fast hardening cement concrete composition provides excellent resistance to drying shrinkage and improved resistance to freezing/thawing, neutralization, and salt damage.

Description

Shrinkage-reducing type polymer modified quick-hardening cement concrete composite and overlay pavement method for concrete using the same}

The present invention relates to a shrinkage-reducing polymer-modified super-fast cement concrete composition having excellent resistance to drying shrinkage and improved resistance to freeze-thaw, neutralization and salt damage, and a concrete overlay pavement method using the same.

The purpose of road pavement is to protect the floor plate of road pavement from impact caused by traffic load, various chemical erosion, and other weather environmental conditions, and at the same time, it is designed and constructed for the purpose of securing drivability of vehicles. As a traditional road paving method, asphalt concrete pavement using asphalt, which is a general road paving material, and a method of using a waterproof sheet have been mainly used. There are serious problems in maintenance that require repair/reinforcement, such as overlaid, to be done within a year.

As an alternative method to solve this problem, a material using polymer dispersion is used, but it has a disadvantage in that the material cost is high.

Therefore, in order to solve this problem, from a technical point of view, polymer cement concrete and non-shrinkable concrete have been developed and used.

On the other hand, from an economical and industrial point of view, it is also necessary to obtain the effect of reducing repair costs by improving the strength and durability of concrete.

On the other hand, cracks occur in the concrete structure, especially in the concrete slab of the bridge, the road surface of the road, and the lower part of the bridge due to deterioration. The exposed concrete undergoes neutralization and corrosion of reinforcing bars occurs. If the corrosion of these reinforcing bars becomes severe, the concrete structure may eventually collapse. Therefore, when cracks occur due to deterioration of the concrete structure, it is necessary to repair the deteriorated portion as soon as possible.

In recent emergency repair work, super-velocity latex-modified concrete in which latex resin is added to super-hard cement is used.

However, due to the high heat of hydration of the ultra-velocity cement used for high-durability concrete pavement, micro-shrinkage occurs and the quality of concrete deteriorates, and moisture and salt penetrate into the bridge slab, which is the main cause of accelerating the deterioration of the structure. In particular, most of the cracks that occur during construction lead to local cracks as well as breakage over time due to the nature of super-velocity cement, which exhibits initial strength, leading to deterioration of the durability of the entire bridge, which leads to serious consequences that cannot fulfill the design life. In addition, since the curing time is very short, about 20 minutes, there are problems in construction such as deterioration of workability, and since the cement price is very high, an increase in the construction cost is inevitable.

Republic of Korea Patent No. 10-1389741 Republic of Korea Patent Registration No. 10-1875461 Republic of Korea Patent Registration No. 10-2088875

The present invention has been devised to solve the above problems, and an embodiment of the present invention has excellent resistance to drying and shrinkage, and a shrinkage-reducing polymer capable of improving durability such as resistance to freeze-thaw, neutralization and salt damage. An object of the present invention is to provide a modified initial velocity cement concrete composition and a concrete overlay pavement method using the same.

Various problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

One embodiment of the present invention contains 5 to 45% by weight of a shrinkage-reducing strength developer, 10 to 75% by weight of fine aggregate, 7 to 65% by weight of coarse aggregate, 0.01 to 25% by weight of a polymer modifier, and 0.1 to 30% by weight of water. As a shrinkage-reducing polymer-modified super-fast cement concrete composition,

The shrinkage-reducing strength generator includes 100 parts by weight of crude steel portland cement, 20 to 40 parts by weight of calcium sulfoaluminate, 1 to 20 parts by weight of tin oxide, 1 to 20 parts by weight of blast furnace slag, 1 to 20 parts by weight of zinc carbonate, and oxidized 0.1 to 10 parts by weight of magnesium, 0.1 to 10 parts by weight of sericite, and 0.1 to 10 parts by weight of calcium sulfate;

The polymer modifier is 100 parts by weight of polymethylmethacrylate-(adamantyl)acrylate copolymer, 20 to 50 parts by weight of styrene-butadiene-styrene copolymer, 10 to 30 parts by weight of N,N-dimethyl acrylamide, It provides a shrinkage-reducing polymer-modified super-fast cement concrete composition comprising 0.1 to 10 parts by weight of phloretin sulfonate represented by Formula 1 and 0.1 to 10 parts by weight of polyrotaxane.

[Formula 1]

The tin oxide is tin oxide sulfated with halosulfonic acid represented by the following formula (2);

The tin oxide sulfated with halosulfonic acid is one selected from the group consisting of SnCl ₂ , SnCl ₂ .2H ₂ O, CH ₃ (CH ₂ ) ₃ SnCl ₃ , SnCl ₄ .5H ₂ O, SnCl ₄ and mixtures thereof. After dissolving the above tin precursor in distilled water, adding ammonia to induce a hydrolysis of the tin precursor until the pH reaches 7.5 to 9.5; After filtering the precipitate by the hydrolysis reaction, drying at a temperature of 60 to 110 ℃ to produce _{tin hydroxide (Sn(OH) 4 );} The resulting tin hydroxide (Sn(OH) ₄ ) is impregnated and stirred in an aqueous solution containing halosulfonic acid represented by the following Chemical Formula 2 at a concentration of 0.5 to 8 M, filtered, and dried at a temperature of 60 to 110 ° C. obtaining a solid product; and heat-treating the solid product at a temperature of 250 to 450° C. to produce tin sulfate oxide.

[Formula 2]

In the above formula, X represents a halogen atom.

The polyrotaxane is a cyclodextrin cyclic molecule, a polybutadiene linear molecule that is skewered in the opening of the cyclodextrin cyclic molecule, and is disposed at both ends of the polybutadiene linear molecule to prevent detachment of the cyclodextrin cyclic molecule having a blocker that prevents; All or part of the hydroxyl group of the cyclodextrin may be substituted with a sulfonic acid group or a sulfuric acid ester group.

The blocking group disposed at both ends of the polybutadiene linear molecule to prevent detachment of the cyclic cyclodextrin molecule may include an anthracene-sorbitol ethoxylate complex represented by the following formula (3).

[Formula 3]

In the above formula, n is an integer from 2 to 10.

In addition, another embodiment of the present invention is a concrete overlay pavement method using the shrinkage-reducing polymer-modified super-fast cement concrete composition,

removing deteriorated, damaged or contaminated parts of a concrete structure such as a road; cleaning the removed area; Primer or blooming treatment on the cleaned area; Restoring the cross section by pouring the shrinkage-reducing polymer-modified super-fast cement concrete composition on the primer or blooming-treated upper portion; applying a film curing agent to the upper portion of the shrinkage-reducing polymer-modified super-fast cement concrete composition to prevent water evaporation and suppress plastic cracks; And it provides a concrete overlay pavement method comprising the step of curing.

According to the shrinkage-reducing polymer-modified super-fast cement concrete composition and the concrete overlay pavement method using the same according to an embodiment of the present invention, it has excellent resistance to drying shrinkage and excellent resistance to long-term cracking including initial shrinkage cracking. there is In addition, it is possible to manufacture tightly sealed concrete by promoting the densification of the tissue, so it has excellent strength characteristics such as flexural strength, tensile strength, initial strength, and long-term strength. There is an effect that can be done. Thereby, there is an effect of reducing the defects of the concrete and extending the service period. In addition, it has the effect that it can be very usefully used for emergency repair work such as paving the road surface and bridge surface by implementing the super fast rigidity and significantly shortening the construction period.

Hereinafter, embodiments of the present invention will be described in detail. However, this is provided as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

One embodiment of the present invention contains 5 to 45% by weight of a shrinkage-reducing strength developer, 10 to 75% by weight of fine aggregate, 7 to 65% by weight of coarse aggregate, 0.01 to 25% by weight of a polymer modifier, and 0.1 to 30% by weight of water. As a shrinkage-reducing polymer-modified super-fast cement concrete composition,

The shrinkage-reducing strength generator includes 100 parts by weight of crude steel portland cement, 20 to 40 parts by weight of calcium sulfoaluminate, 1 to 20 parts by weight of tin oxide, 1 to 20 parts by weight of blast furnace slag, 1 to 20 parts by weight of zinc carbonate, and oxidized 0.1 to 10 parts by weight of magnesium, 0.1 to 10 parts by weight of sericite, and 0.1 to 10 parts by weight of calcium sulfate;

The polymer modifier is 100 parts by weight of polymethylmethacrylate-(adamantyl)acrylate copolymer, 20 to 50 parts by weight of styrene-butadiene-styrene copolymer, 10 to 30 parts by weight of N,N-dimethyl acrylamide, It provides a shrinkage-reducing polymer-modified super-fast cement concrete composition comprising 0.1 to 10 parts by weight of phloretin sulfonate represented by Formula 1 and 0.1 to 10 parts by weight of polyrotaxane.

[Formula 1]

According to the shrinkage-reducing polymer-modified super-fast cement concrete composition and the concrete overlay pavement method using the same according to an embodiment of the present invention, it has excellent resistance to drying shrinkage and excellent resistance to long-term cracking including initial shrinkage cracking. there is In addition, it is possible to manufacture tightly sealed concrete by promoting the densification of the tissue, so it has excellent strength characteristics such as flexural strength, tensile strength, initial strength, and long-term strength. There is an effect that can be done. Thereby, there is an effect of reducing the defects of the concrete and extending the service period. In addition, it has the effect that it can be very usefully used for emergency repair work such as paving the road surface and bridge surface by implementing the super fast rigidity and significantly shortening the construction period.

More specifically, the shrinkage-reducing polymer-modified initial velocity cement concrete composition according to an embodiment of the present invention contains 5 to 45% by weight of a shrinkage-reducing strength developer, 10 to 75% by weight of fine aggregate, 7 to 65% by weight of coarse aggregate, 0.01 to 25% by weight of a polymer modifier and 0.1 to 30% by weight of water.

The aggregate used in the present invention is divided into fine aggregate and coarse aggregate. Those with a particle diameter of 5 mm or less are called fine aggregates, and those with a particle diameter greater than 5 mm are classified as coarse aggregates. The fine aggregate is preferably contained in an amount of 10 to 75% by weight based on the shrinkage-reducing polymer-modified super-velocity cement concrete composition of the present invention, and the coarse aggregate is 7 to 65 with respect to the shrinkage-reducing polymer-modified super-velocity cement concrete composition of the present invention. It is preferably contained in % by weight.

The shrinkage-reducing strength generator used in the present invention promotes the initial hydration of cement and the densification of the tissue to make tight concrete, and it is possible to secure the initial strength after application, greatly shortening the construction period and reducing the traffic control time. There is a minimization effect. In addition, by mixing with the polymer modifier of the present invention, the resistance to freeze-thaw, neutralization and salt damage is greatly improved, and there is an effect of securing long-term usability of the repaired road. In addition, it has excellent resistance to drying shrinkage, excellent resistance to long-term cracking including initial shrinkage cracking, and excellent water resistance, chemical resistance and neutralization resistance. In addition, the adhesion performance with the existing bridge pavement is excellent, and the mechanical properties such as flexural strength, tensile strength, initial strength, and long-term strength are very strengthened, so there is an effect that can effectively prevent surface cracking and expansion fracture of concrete.

In consideration of the above-described improvement effect, the shrinkage-reducing strength developer is preferably contained in an amount of 5 to 45% by weight based on the shrinkage-reducing polymer-modified initial velocity cement concrete composition of the present invention.

The shrinkage-reducing strength developer includes 100 parts by weight of crude portland cement, 20 to 40 parts by weight of calcium sulfoaluminate, 1 to 20 parts by weight of tin oxide, 1 to 20 parts by weight of blast furnace slag, 1 to 20 parts by weight of zinc carbonate, 0.1 to 10 parts by weight of magnesium oxide, 0.1 to 10 parts by weight of sericite, and 0.1 to 10 parts by weight of calcium sulfate may be preferably used.

It is preferable to use the crude Portland cement specified in KS, and it is preferable to use a fineness of 5,000 to 9,000 cm2/g.

Hereinafter, the content of the components constituting the shrinkage reduction type strength presenter is based on 100 parts by weight of the crude Portland cement.

The calcium sulfoaluminate provides fast curing properties, and functions to exhibit super-fast curing properties.

The calcium sulfoaluminate is preferably contained in an amount of 20 to 40 parts by weight based on 100 parts by weight of the crude Portland cement. When the content of the calcium sulfoaluminate is too small, there is a problem that the above-described improvement effect may be insufficient. There is a problem in that price competitiveness may be lowered.

The tin oxide functions to improve toughness, improve adhesive strength and flexural strength, and greatly improve long-term strength. In addition, by greatly improving corrosion resistance, chemical resistance and chemical resistance, it functions to provide very improved durability such as salt penetration resistance and freeze thaw resistance.

The tin oxide has the effect of further improving the above-described improvement effect by using the tin oxide sulfated with halosulfonic acid represented by the following Chemical Formula 2, and further accelerating the curing rate.

[Formula 2]

In the above formula, X represents a halogen atom.

More specifically, the tin oxide sulfated with halosulfonic acid is SnCl ₂ , SnCl ₂ .2H ₂ O, CH ₃ (CH ₂ ) ₃ SnCl ₃ , SnCl ₄ .5H ₂ O, SnCl _{4 From} the group consisting of and mixtures thereof. After dissolving at least one selected tin precursor in distilled water, adding ammonia to induce hydrolysis of the tin precursor until pH reaches 7.5 to 9.5; After filtering the precipitate by the hydrolysis reaction, drying at a temperature of 60 to 110 ℃ to produce _{tin hydroxide (Sn(OH) 4 );} The resulting tin hydroxide (Sn(OH) ₄ ) is impregnated and stirred in an aqueous solution containing halosulfonic acid represented by the following Chemical Formula 2 at a concentration of 0.5 to 8 M, filtered, and dried at a temperature of 60 to 110 ° C. obtaining a solid product; and heat-treating the solid product at a temperature of 250 to 450 ° C. to produce tin sulfate. Prepared by a method comprising, sulfate ions (SO ₄ ^2- ) in the final produced tin sulfate oxide It is preferably used in an amount of 4 to 17% by weight.

The tin oxide is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the crude Portland cement. When the content of the tin oxide is too small, there is a problem that the above-described improvement effect may be insufficient, and when the content of the tin oxide is too large, there is a problem that the workability may be reduced due to the increase in viscosity and decrease in fluidity. .

The blast furnace slag functions to improve durability such as long-term strength, freeze-thaw resistance, and chloride ion permeation resistance due to its latent hydraulic properties.

Such blast furnace slag is a by-product of the steel industry _{, and its main components are CaO and SiO 2} , and although its composition is similar to that of cement, it _{does not generate CO 2} , so it is environmentally friendly. More specifically, the blast furnace slag is generated during the blast furnace ironmaking process, and when the slag is discharged, the blast furnace slag in a high temperature molten state is sprayed and quenched to form amorphous granules with an average particle diameter of less than 5 mm. In addition, by pulverizing the water-based slag, a powder having a fineness of 4,000 to 8,000 cm 2 /g may be preferably used.

The blast furnace slag is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the crude steel portland cement. If the content of the blast furnace slag is too small, the improvement effect may be insufficient, and if the content of the blast furnace slag is too large, the initial strength may be lowered.

The zinc carbonate improves toughness, improves adhesive strength and flexural strength, greatly improves long-term strength, has excellent resistance to drying shrinkage, and improves resistance to long-term cracking and expansion fracture including initial shrinkage cracking. do

The zinc carbonate is preferably contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the crude Portland cement. When the content of the zinc carbonate is too small, there is a problem that the above-described improvement effect may be insufficient, and when the content of the zinc carbonate is too large, there is a problem that the initial strength may be lowered.

The magnesium oxide has excellent resistance to drying shrinkage, and functions to improve resistance to long-term cracking including initial shrinkage cracking.

The magnesium oxide uses magnesium oxide having the form of a hollow sphere, and by improving corrosion resistance, chemical resistance and chemical resistance as well as the above-mentioned improvement effect, very improved durability such as salt penetration resistance and freeze-thaw resistance can be provided. there is an effect

More specifically, the magnesium oxide having a hollow sphere shape is prepared by dissolving magnesium nitrate, magnesium sulfate, bead-shaped polystyrene and carboxylic acid in a solvent to prepare a precursor solution; generating droplets by applying ultrasonic waves to the precursor solution, and spraying the droplets into a reactor using a carrier gas; pyrolyzing the droplets at a temperature of 400 to 900° C. to prepare magnesium oxide hollow spheres; and heat-treating the prepared magnesium oxide hollow spheres at a temperature of 150 to 350° C. to prepare magnesium oxide hollow spheres with increased crystallinity.

In this case, the bead-type polystyrene may preferably have an average particle size of 50 to 120 nm.

In addition, the carboxylic acid may preferably be at least one selected from the group consisting of oxalic acid, succinic acid, tartaric acid, glutamic acid, adipic acid, terephthalic acid, phthalic acid, malonic acid, maleic acid, fumaric acid, and mixtures thereof.

In addition, the solvent is dimethylacetamide, dimethylformamide, acetic acid, n-methyl-2-pyrrolidone (NMP), formic acid, nitromethane, methanol, ethanol, propanol, iso-propanol, tert-butanol, n-butanol , methoxyethanol, ethoxyethanol, may be at least one selected from the group consisting of water and mixtures thereof, preferably, may be a mixed solvent of dimethylacetamide and acetic acid, more preferably, dimethylacetamide and acetic acid may be mixed in a volume ratio of 1:1 to 10, respectively.

In addition, the carrier gas may preferably be at least one selected from the group consisting of air, nitrogen, oxygen, helium, argon, and a mixed gas thereof.

The magnesium oxide is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the crude Portland cement. When the content of the magnesium oxide is too small, there is a problem that the above-described improvement effect may be insufficient, and when the content of the magnesium oxide is too large, there is a problem that the curing speed may be delayed.

The sericite has a small scaly or lobed structure, has fine particles, provides excellent covering power to protect the composition, and prevents the viscosity from being lowered so that the adhesive strength is maintained for a long time. Accordingly, it functions to improve not only durability such as strength, fire resistance, heat insulation and water resistance, but also storage stability. In addition, it has excellent resistance to drying shrinkage and excellent resistance to long-term cracking including initial shrinkage cracking.

Since the sericite is in the form of a magnesium-agglomerated magnesium-sericite aggregate, there is an effect that can further contribute to the improvement of initial strength as well as the aforementioned improvement effect.

More specifically, the magnesium-sericite aggregate may be prepared by mixing 100 parts by weight of sericite and 15 to 25 parts by weight of _{MgCl 2} ·H _{2 O;} 150 to 300 parts by weight of distilled water mixed with the mixed sericite and MgCl _{2 ·H 2 O and stirred for 5 to 30 hours;} After centrifuging the stirred sericite, MgCl ₂ ·H ₂ O and distilled water, extracting the supernatant to obtain a magnesium-sericite aggregate; mixing the obtained magnesium-sericite aggregate with neohesperidin in an amount of 1: 0.1 to 0.5 parts by weight, followed by ball milling; and drying the pulverized magnesium-sericite agglomerates at a temperature of 50 to 80 ° C. , there is an effect that can further improve the above-described effect, there is an effect that the antioxidant performance is improved.

The sericite is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the crude steel portland cement. When the content of sericite is too small, there is a problem that the above improvement effect may be insufficient, and when the content of sericite is too large, there is a problem that workability may be deteriorated due to viscosity increase and fluidity decrease. .

The calcium sulfate functions to provide fast curing properties, secure initial strength, and has excellent resistance to drying shrinkage, and to improve resistance to long-term cracking including initial shrinkage cracking.

The above-mentioned improvement effect may be further improved by using a mixture of alpha-calcium sulfate hemihydrate and calcium sulfate dihydrate in a weight ratio of 1: 1 to 3 as the calcium sulfate.

The calcium sulfate is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the crude Portland cement. When the content of the calcium sulfate is too small, there is a problem that the above-described improvement effect may be insufficient, and when the content of the calcium sulfate is too large, there is a problem that the strength characteristics may be deteriorated due to excessive expansion.

On the other hand, the polymer modifier used in the present invention is 100 parts by weight of polymethylmethacrylate-(adamantyl)acrylate copolymer, 20 to 50 parts by weight of styrene-butadiene-styrene copolymer, N,N-dimethyl acrylamide 10 to 30 parts by weight, including 0.1 to 10 parts by weight of phloretin sulfonate represented by the following Chemical Formula 1 and 0.1 to 10 parts by weight of polyrotaxane; It has excellent material and construction stability against external temperature changes, and can provide very improved durability such as excellent strength, waterproofness, salt penetration resistance, freeze-thaw resistance, etc., and has the effect of providing very improved workability. Accordingly, there is an effect of very excellent resistance to long-term cracking including initial shrinkage cracking.

[Formula 1]

In consideration of the above-described improvement effect, the polymer modifier is preferably included in an amount of 0.01 to 25% by weight of the shrinkage reduction type polymer-modified initial velocity cement concrete composition according to an embodiment of the present invention.

The polymethyl methacrylate-(adamantyl) acrylate copolymer functions to improve bonding strength and durability.

More specifically, the polymethylmethacrylate-(adamantyl)acrylate copolymer comprises 25 to 45% by weight of polymethylmethacrylate; By copolymerizing 55 to 75 wt% of (adamantyl)acrylate, not only the above effects, but also excellent strength performance and neutralization resistance can be further improved.

In this case, the (adamantyl) acrylate is 3-hydroxy-1- (adamantyl) acrylate, 3,5-dihydroxy-1- (adamantyl) acrylate, 3,5,7- Trihydroxy-1-(adamantyl)acrylate, 3,5-dimethyl-1-(adamantyl)acrylate, 5,7-dimethyl-3-hydroxy-1-(adamantyl)acrylate And at least one selected from the group consisting of mixtures thereof may be preferably used.

Hereinafter, the content of the components constituting the polymer modifier is based on 100 parts by weight of the polymethyl methacrylate-(adamantyl) acrylate copolymer.

The styrene-butadiene-styrene copolymer improves bonding strength and durability, and in particular functions to improve flexural strength, compressive strength and adhesive strength. At the same time, it has good flowability and has a small amount of air, providing excellent workability and workability.

It is a thermoplastic elastomer produced by anionic polymerization with styrene and butadiene as main components. It is largely divided into linear and radial products depending on the molecular structure, and can be selected and used in various ways depending on the purpose.

The styrene-butadiene-styrene copolymer is preferably contained in an amount of 20 to 50 parts by weight based on 100 parts by weight of the polymethylmethacrylate-(adamantyl)acrylate copolymer. When the content of the styrene-butadiene-styrene copolymer is too small, the above improvement effect may be insufficient, and when the content of the styrene-butadiene-styrene copolymer is too large, the initial strength expression may be reduced. there is a problem with

The N,N-dimethyl acrylamide functions to improve bonding strength, tensile strength and durability.

The N,N-dimethyl acrylamide is preferably contained in an amount of 10 to 30 parts by weight based on 100 parts by weight of the polymethylmethacrylate-(adamantyl)acrylate copolymer. When the content of N,N-dimethyl acrylamide is too small, there is a problem that the above improvement effect may be insufficient, and when the content of N,N-dimethyl acrylamide is too large, the initial strength expression may be reduced. there is a problem with

Phloretin sulfonate represented by Formula 1 serves to accelerate the curing rate, reduce drying shrinkage, effectively reduce cracking, and improve water resistance, salt damage and freeze-thaw resistance.

Phloretin sulfonate represented by Formula 1 is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the polymethylmethacrylate-(adamantyl)acrylate copolymer. When the content of Phloretin sulfonate represented by Formula 1 is too small, there is a problem that the above-described improvement effect may be insufficient, and the content of Phloretin sulfonate represented by Formula 1 If there are too many of these, there is a problem that workability may be lowered or price competitiveness may be lowered.

The polyrotaxane improves workability by reducing bleeding of concrete, and has excellent material and construction stability against external temperature changes to ensure uniform quality of concrete and improve watertightness and durability, as well as to prevent shrinkage cracking very effectively has a deterrent function.

The polyrotaxane is a cyclodextrin cyclic molecule, a polybutadiene linear molecule that is skewered in the opening of the cyclodextrin cyclic molecule, and is disposed at both ends of the polybutadiene linear molecule to prevent detachment of the cyclodextrin cyclic molecule having a blocker that prevents; By using that all or part of the hydroxyl groups of the cyclodextrin are substituted with sulfonic acid groups or sulfuric ester groups, the above-described effects can be further improved, and initial strength can be secured through rapid curing.

In this case, the blocking groups disposed at both ends of the polybutadiene linear molecule to prevent the detachment of the cyclodextrin cyclic molecule are dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes. Or it may be an anthracene.

More specifically, the blocking group disposed at both ends of the polybutadiene linear molecule to prevent detachment of the cyclodextrin cyclic molecule includes an anthracene-sorbitol ethoxylate complex represented by the following Chemical Formula 3 to achieve the above effect can be further improved.

[Formula 3]

In the above formula, n is an integer from 2 to 10.

The polyrotaxane is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the polymethylmethacrylate-(adamantyl)acrylate copolymer. When the content of the polyrotaxane is too small, there is a problem that the above-described improvement effect may be insufficient, and when the content of the polyrotaxane is too large, there is a problem that price competitiveness may be lowered.

The shrinkage-reducing polymer-modified super-velocity cement concrete composition according to a preferred embodiment of the present invention comprises 5 to 45% by weight of a shrinkage-reducing strength developer, 10 to 75% by weight of fine aggregate, and 7 to 65% by weight of coarse aggregate in a forced mixer. After mixing, 0.01 to 25% by weight of a polymer modifier and 0.1 to 30% by weight of water may be further mixed and stirred for a predetermined time (eg, 1 to 10 minutes).

In addition, another embodiment of the present invention is a concrete overlay pavement method using the shrinkage-reducing polymer-modified super-fast cement concrete composition,

removing deteriorated, damaged or contaminated parts of a concrete structure such as a road; cleaning the removed area; Primer or blooming treatment on the cleaned area; Restoring the cross section by pouring the shrinkage-reducing polymer-modified super-fast cement concrete composition on the primer or blooming-treated upper portion; applying a film curing agent to the upper portion of the shrinkage-reducing polymer-modified super-fast cement concrete composition to prevent water evaporation and suppress plastic cracks; And it provides a concrete overlay pavement method comprising the step of curing.

In this case, the deterioration part may be removed to the lower part where the reinforcing bar exists, and after cleaning the removed portion, removing the rust of the exposed reinforcing bar before the primer or blooming process may be further included.

In the case of chipping using a chipping device such as a crusher or a water jet in the step of removing the deteriorated part, the reinforcing bars of the concrete structure are not exposed in normal cases. In the case of exposure, a separate anti-rust treatment must be performed, but according to the present invention, a separate reinforcing bar anti-rust treatment is not required.

In the curing step, depending on the atmospheric conditions including the temperature, humidity, and wind strength of the site, 1) only the curing agent is sprayed, or 2) after the curing agent is sprayed, a vinyl or curing cloth is covered on the upper part and sprayed to a wet state or 3) after spraying the curing agent, it is recommended to apply the curing step separately while maintaining the warmth using vinyl, curing cloth, or a thermal insulation cover.

In particular, in the curing step, in the case of on-site atmospheric conditions (for example, in the case of atmospheric conditions with high atmospheric temperature (25 ℃ or more), low relative humidity, and windy conditions, such as in summer, vinyl, curing cloth, etc. Conversely, if the atmospheric temperature (below 25℃) is not high, relative humidity is high, and there is little wind, spray only curing agent and cure according to). After spraying, cover the top with vinyl, curing cloth, etc. In addition, when the atmospheric temperature is 5 ℃ or less, after spraying the curing agent, it may further include the step of performing thermal insulation curing using vinyl, curing cloth, insulation cover, etc.

Hereinafter, the primer or blooming treatment is used to refer to an operation for facilitating adhesion of the shrinkage-reducing polymer-modified super-fast cement concrete composition according to an embodiment of the present invention to a concrete structure.

As the primer material, at least one selected from SBR (Styrene Butadiene Rubber) latex, Poly Acryl Ester (PAE), epoxy emulsion, Ethyl Vinyl Acetate (EVA) and acrylic emulsion is selected. can be used

In addition, the blooming material is generally used in the art and the type thereof is not particularly limited, but a polymer modifier of the shrinkage-reducing polymer-modified super-fast cement concrete composition is mixed with the blooming material generally used in the art. can be used

According to the shrinkage-reducing polymer-modified super-fast cement concrete composition and the concrete overlay pavement method using the same according to an embodiment of the present invention, it has excellent resistance to drying shrinkage and excellent resistance to long-term cracking including initial shrinkage cracking. there is In addition, it is possible to manufacture tightly sealed concrete by promoting the densification of the tissue, so it has excellent strength characteristics such as flexural strength, tensile strength, initial strength, and long-term strength. There is an effect that can be done. Thereby, there is an effect of reducing the defects of the concrete and extending the service period. In addition, it has the effect that it can be very usefully used for emergency repair work such as paving the road surface and bridge surface by implementing the super fast rigidity and significantly shortening the construction period.

As mentioned above, although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the above embodiment, and various modifications can be made by those skilled in the art within the scope of the technical spirit of the present invention. This is possible.

<Production Example 1>

Preparation of tin oxide sulfated with halosulfonic acid

25 g of SnCl ₄ 5H ₂ O (tin chloride pentahydrate) was dissolved in 500 ml of distilled water, and then aqueous ammonia (30 wt% concentration) was added until the pH of the aqueous solution reached 8 while stirring at room temperature. A _{hydrolysis reaction of SnCl 4} ·5H ₂ O was induced.

At this time, the precipitate by the hydrolysis reaction is filtered to obtain a solid product, which is thoroughly washed with distilled water, put in a drying oven, and dried at 110 ° C. for 15 hours to produce 5.5 g of tin hydroxide (Sn(OH) ₄ ) did

The produced tin hydroxide (Sn(OH) ₄ ) was impregnated in an aqueous solution containing 3 M concentration of halosulfonic acid represented by the following Chemical Formula 2-1 at a ratio of 15 ml per g, stirred for 1 hour and filtered to obtain a solid product , and the obtained solid product was washed with distilled water and then placed in a drying oven and dried at 110 °C for 2 hours.

The dried solid product was put in an electric furnace and heat-treated at 400 °C for 5 hours under an air atmosphere to prepare 5.4 g of tin sulfate oxide as a final product.

_{The content of sulfate ions (SO 4} ^2- ) in the final product, tin sulfate, was measured by thermogravimetric analysis (TGA), and the measured content was 7.8 wt%.

[Formula 2-1]

Wherein X is Cl.

<Preparation Example 2>

Preparation of magnesium oxide in the form of hollow spheres

After dissolving a mixture of dimethylacetamide and acetic acid in a mixed solvent having a volume ratio of 1:2.5 and magnesium nitrate and magnesium sulfate in a weight ratio of 1:1 until the solution becomes transparent, polystyrene beads having an average particle size of 75 nm A precursor solution was prepared by further mixing 42 g and 3 g of oxalic acid. The precursor solution in the oil bath was injected into an ultrasonic nebulizer for use in spray pyrolysis. Ultrasonic waves were applied to the precursor solution to generate droplets, and the droplets were transferred to an electric furnace using nitrogen gas and pyrolyzed at a temperature of 600° C. to prepare magnesium oxide hollow spheres. Thereafter, by heat-treating the prepared magnesium oxide hollow spheres in an argon gas atmosphere and a temperature of 300° C., magnesium oxide hollow spheres with increased crystallinity were prepared.

<Production Example 3>

Preparation of sericite

As sericite, the form of magnesium-sericite aggregate was used.

The magnesium-sericite aggregate is prepared by mixing 100 parts by weight of sericite and 22 parts by weight of _{MgCl 2} ·H _{2 O;} 210 parts by weight of distilled water mixed with the mixed sericite and MgCl ₂ ·H _{2 O and stirred for 19 hours;} and centrifuging the stirred sericite, MgCl ₂ ·H ₂ O and distilled water, and extracting the supernatant to obtain magnesium-sericite aggregates; mixing the obtained magnesium-sericite aggregate with neohesperidin in 1:0.2 parts by weight, followed by ball milling; and drying the pulverized magnesium-sericite aggregate at a temperature of 70 °C.

<Production Example 4>

Preparation of polyrotaxane

As a polyrotaxane, a cyclodextrin cyclic molecule, a polybutadiene linear molecule that is skewered in the opening of the cyclodextrin cyclic molecule, and a polybutadiene linear molecule disposed at both ends of the cyclodextrin cyclic molecule to prevent detachment of the cyclodextrin cyclic molecule having a blocking group (anthracene group) that prevents; Among the hydroxyl groups of the cyclodextrin, those in which 50% were substituted with sulfate ester groups were used.

<Preparation Example 5>

Preparation of polyrotaxane

As a polyrotaxane, a cyclodextrin cyclic molecule, a polybutadiene linear molecule that is skewered in the opening of the cyclodextrin cyclic molecule, and a polybutadiene linear molecule disposed at both ends of the cyclodextrin cyclic molecule to prevent detachment of the cyclodextrin cyclic molecule having a blocker that prevents; Among the hydroxyl groups of the cyclodextrin, those in which 50% were substituted with sulfate ester groups were used.

At this time, the blocking group disposed at both ends of the polybutadiene linear molecule to prevent the detachment of the cyclodextrin cyclic molecule is an anthracene group and an anthracene-sorbitol ethoxylate complex represented by the following Chemical Formula 3-1 in a 5:1 molar ratio What was included was used.

[Formula 3-1]

In the above formula, n is 2.

<Examples and Comparative Examples>

The shrinkage-reducing strength generator, fine aggregate, and coarse aggregate mixed with the components and contents as shown in Table 1 below were put in a forced mixing mixer, and then mixed under dry mixing conditions for 3 minutes, as shown in Table 1 below. Water and a polymer modifier mixed as components and contents were simultaneously added and mixed for 1 minute and 30 seconds to prepare a shrinkage-reducing polymer-modified super-fast cement concrete composition and a comparative concrete composition.

Category (wt%) Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 fine aggregate 38 38 38 38 38 coarse aggregate 32 32 32 32 32 water 1.5 1.5 1.5 1.5 1.5 Shrinkage reduction type strength generator 25 25 25 25 25 (parts by weight) crude steel portland cement
(Powder: 6,210 ㎠/g) 100 100 100 100 100 Calcium sulfoaluminate 23 23 23 23 23 tin oxide 11
(usual
tin oxide powder) 8
(Production Example 1) 8
(Production Example 1) - - blast furnace slag
(Powder: 5,640 ㎠/g) 13 13 13 13 - zinc carbonate 8 8 8 - - magnesium oxide 5
(usual
magnesium oxide powder) 5
(usual
magnesium oxide powder) 3
(Production Example 2) - - sericite 4
(usual
sericite powder) 4
(usual
sericite powder) 5
(Production Example 3) - - Calcium sulfate ¹⁾ 2 2 2 - - ^{1) A} mixture of alpha-calcium sulfate hemihydrate and calcium sulfate dihydrate in a weight ratio of 1: 2 is used. polymer modifier 3.5 3.5 3.5 3.5 3.5 (parts by weight) Polymethylmethacrylate-(adamantyl)acrylate copolymer ²⁾ 100 100 100 100 100 Styrene-Butadiene-Styrene Copolymer 37 37 37 37 - N,N-dimethyl acrylamide 14 14 14 - - phloretin sulfonate
(Formula 1) 3 3 3 - - polyrotaxane 5
(Production Example 4) 4
(Production Example 5) 4
(Production Example 5) - - ²⁾ Use the one obtained by copolymerizing 38 wt% of polymethyl methacrylate and 62 wt% of 3,5-dihydroxy-1-(adamantyl)acrylate

The following test examples are experiments comparing the properties of Examples 1 and 2 according to the present invention with those of Comparative Examples 1 and 2 in order to more easily understand the characteristics of Examples 1 to 3 according to the present invention disclosed above. the results are shown.

<Test Example 1>

The shrinkage reduction polymer-modified initial velocity cement concrete composition of Examples 1 to 3 described above and the comparative concrete compositions prepared in Comparative Examples 1 and 2 were subjected to a slump test according to the method specified in KS F 2402 ( It shows the result of kneading the dough). The slump test tests the toughness of the dough, such as the softness and consistency of concrete, and the higher the number, the better the workability, that is, the workability when pouring concrete.

Table 2 below shows the change in slump over time.

division Slump (cm) Immediately after stirring after 20 minutes after 30 minutes after 40 minutes after 60 minutes Example 1 17 16 15 14 13 Example 2 17 16 14 13 13 Example 3 18 17 15 15 14 Comparative Example 1 14 11 8 5 4 Comparative Example 2 11 9 6 4 2

As shown in Table 2, it was confirmed that Examples 1 to 3 according to the present invention had excellent workability compared to Comparative Examples 1 and 2.

<Test Example 2>

The compressive strength test was performed on the shrinkage-reducing polymer-modified initial velocity cement concrete composition according to Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 according to the method specified in KS F 2405. the results are shown.

Table 3 below shows the change in compressive strength over time.

division Compressive strength (kgf/㎠) after 3 hours after 12 hours after 24 hours 3 days later 28 days later Example 1 301 327 346 407 527 Example 2 305 336 350 418 533 Example 3 311 347 358 432 541 Comparative Example 1 - - - 176 355 Comparative Example 2 - - - 154 312

As shown in Table 3, in Examples 1 to 3 according to the present invention, it is possible to perform another operation on the poured concrete because it is easy to harden quickly. It can be seen that the implementation is difficult. In addition, it was confirmed that Examples 1 to 3 were superior to Comparative Examples 1 and 2 according to the present invention in compressive strength after complete curing.

<Test Example 3>

The results of measuring the flexural strength of the shrinkage-reducing polymer-modified super-velocity cement concrete composition of Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 according to the method specified in KS F 2408 were obtained. it has been shown

Table 4 below shows the change in flexural strength over time.

division Warp (kgf/㎠) after 3 hours after 12 hours after 24 hours 3 days later 28 days later Example 1 69 80 85 110 133 Example 2 72 81 89 113 136 Example 3 75 88 92 116 140 Comparative Example 1 - - - 47 65 Comparative Example 2 - - - 18 32

As shown in Table 4, in Examples 1 to 3 according to the present invention, rapid hardening proceeded and no deformation of concrete occurred, but Comparative Examples 1 and 2 had a slow curing progress, so when an external load was applied It can be confirmed that the poured concrete can be damaged or deformed. In addition, it was confirmed that Examples 1 to 3 were superior to Comparative Examples 1 and 2 in flexural strength after complete curing.

<Test Example 4>

Adhesive strength of the shrinkage-reducing polymer-modified super-fast cement concrete composition of Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 was measured according to the method specified in KS F 2762, The results are shown in Table 5.

division Adhesive strength (kgf/㎠) after 3 hours after 12 hours after 24 hours 3 days later 28 days later Example 1 19 22 24 27 30 Example 2 21 23 25 29 32 Example 3 22 23 25 30 33 Comparative Example 1 - - - 12 19 Comparative Example 2 - - - - 11

As shown in Table 5, it was confirmed that Examples 1 to 3 according to the present invention had superior adhesive strength compared to Comparative Examples 1 and 2.

<Test Example 5>

The water absorption rate of the shrinkage-reducing polymer-modified initial velocity cement concrete composition of Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 according to the method specified in KS F 4004 (cement bricks). was measured, and the results are shown in Table 6. If the water absorption rate is high, if impurities or water penetrate into the interior of the concrete, the porosity increases in the interior of the concrete, causing a problem that causes damage to the structure. That is, the lower the water absorption, the higher the strength of the concrete after hardening.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Absorption rate (%) 1.1 1.0 0.8 6.5 9.4

As shown in Table 6, it was confirmed that Examples 1 to 3 according to the present invention had a lower water absorption than Comparative Examples 1 and 2.

<Test Example 6>

The freeze-thaw resistance test was performed on the shrinkage-reducing polymer-modified super-fast cement concrete composition of Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 according to the method specified in KS F 2456. was performed, and the durability index results of each of Examples and Comparative Examples according to the freeze-thaw resistance test are shown in Table 7. Freeze-thaw refers to the freezing and melting of moisture absorbed in concrete. If freeze-thaw is repeated, microcracks occur in the concrete structure, resulting in deterioration of durability.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 durability index 95 96 97 56 41

As shown in Table 7, it was confirmed that Examples 1 to 3 according to the present invention were superior in durability, ie, freeze-thaw resistance, compared to Comparative Examples 1 and 2.

<Test Example 7>

The shrinkage-reducing polymer-modified super-fast cement concrete composition of Examples 1 to 3 and the comparative concrete composition prepared in Comparative Examples 1 and 2 were dried according to KS F 2424 (Test method for length change of concrete). Shrinkage was measured, and the results are shown in Table 8 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Drying shrinkage (×10 ^-4 ) 0.2 0.1 0.1 4.5 4.9

As shown in Table 8, in Examples 1 to 3 according to the present invention, it was confirmed that the drying shrinkage amount was reduced compared to Comparative Examples 1 and 2.

<Test Example 8>

Test according to JIS A 1171 (Test method for polymer cement mortar) of the shrinkage reduction polymer-modified super-fast cement concrete compositions of Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 was performed, and the results are shown in Table 9.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Neutralization depth (mm) 0.8 0.8 0.7 2.1 2.3

As shown in Table 9, it was confirmed that Examples 1 to 3 according to the present invention showed less neutralization penetration than Comparative Examples 1 and 2.

<Test Example 9>

The tests according to JIS A 1171 were performed on the shrinkage-reducing polymer-modified initial velocity cement concrete compositions of Examples 1 to 3 and the comparative concrete compositions prepared in Comparative Examples 1 and 2 according to JIS A 1171, and the results are shown below. Table 10 shows.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Chloride ion penetration depth (mm) 1.2 1.0 0.7 2.1 2.5

As shown in Table 10, in Examples 1 to 3 according to the present invention, it was confirmed that the chloride ion penetration depth was small compared to Comparative Examples 1 and 2.

As described above, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential characteristics thereof. Therefore, it should be understood that all of the embodiments described above are illustrative and not restrictive. The scope of the present invention should be construed as being included in the scope of the present invention, rather than the above detailed description, all changes or modifications derived from the meaning and scope of the claims to be described later and their equivalents.

Claims (5)

Shrink-reducing polymer-modified initial velocity comprising 5 to 45% by weight of a shrinkage-reducing strength developer, 10 to 75% by weight of fine aggregate, 7 to 65% by weight of coarse aggregate, 0.01 to 25% by weight of a polymer modifier, and 0.1 to 30% by weight of water A light cement concrete composition comprising:
The shrinkage reduction type strength generator is
100 parts by weight of crude Portland cement, 20 to 40 parts by weight of calcium sulfoaluminate, 1 to 20 parts by weight of tin oxide, 1 to 20 parts by weight of blast furnace slag, 1 to 20 parts by weight of zinc carbonate, 0.1 to 10 parts by weight of magnesium oxide, Seri 0.1 to 10 parts by weight of site and 0.1 to 10 parts by weight of calcium sulfate;
The polymer modifier is
100 parts by weight of polymethylmethacrylate-(adamantyl)acrylate copolymer, 20 to 50 parts by weight of styrene-butadiene-styrene copolymer, 10 to 30 parts by weight of N,N-dimethyl acrylamide, represented by the following formula (1) It will contain 0.1 to 10 parts by weight of phloretin sulfonate and 0.1 to 10 parts by weight of polyrotaxane;
The tin oxide is tin oxide sulfated with halosulfonic acid represented by the following formula (2);
The tin oxide sulfated with the halosulfonic acid is
SnCl ₂ , SnCl ₂ ㆍ2H ₂ O, CH ₃ (CH ₂ ) ₃ SnCl ₃ , SnCl ₄ ㆍ5H ₂ O, SnCl ₄ and at least one tin precursor selected from the group consisting of a mixture thereof is dissolved in distilled water , inducing hydrolysis of the tin precursor until the pH reaches 7.5 to 9.5 by adding ammonia;
After filtering the precipitate by the hydrolysis reaction, drying at a temperature of 60 to 110 ℃ to produce _{tin hydroxide (Sn(OH) 4 );}
The resulting tin hydroxide (Sn(OH) ₄ ) is impregnated and stirred in an aqueous solution containing halosulfonic acid represented by the following Chemical Formula 2 at a concentration of 0.5 to 8 M, filtered, and dried at a temperature of 60 to 110 ° C. obtaining a solid product; and
Heat-treating the solid product at a temperature of 250 to 450 °C to produce tin sulfate.
[Formula 1]

[Formula 2]

In the above formula, X represents a halogen atom.
delete According to claim 1,
The polyrotaxane is
A cyclodextrin cyclic molecule, a polybutadiene linear molecule clad in an opening of the cyclodextrin cyclic molecule in a skewer shape, and a blocking group disposed at both ends of the polybutadiene linear molecule to prevent detachment of the cyclodextrin cyclic molecule will;
All or part of the hydroxyl groups of the cyclodextrin are substituted with a sulfonic acid group or a sulfate ester group.
4. The method of claim 3,
Blocking groups disposed at both ends of the polybutadiene linear molecule to prevent detachment of the cyclic cyclodextrin molecule
A shrinkage-reducing polymer-modified super-fast cement concrete composition comprising an anthracene-sorbitol ethoxylate complex represented by the following formula (3).
[Formula 3]

In the above formula, n is an integer from 2 to 10.
A concrete overlay pavement method using the shrinkage-reducing polymer-modified super-velocity cement concrete composition according to any one of claims 1, 3 and 4,
removing deteriorated, damaged or contaminated parts of a concrete structure such as a road; cleaning the removed area; Primer or blooming treatment on the cleaned area; Restoring the cross section by pouring the shrinkage-reducing polymer-modified super-fast cement concrete composition on the primer or blooming-treated upper portion; applying a film curing agent to the upper portion of the shrinkage-reducing polymer-modified super-fast cement concrete composition to prevent water evaporation and suppress plastic cracks; And concrete overlay pavement method comprising the step of curing.