KR101940645B1 - Crack-Reducing Type Fast Curing Concrete Composition, And Method For Repairing And Rehabilitating Road Pavement Using The Composition - Google Patents

Abstract

The present invention relates to a crack-reducing type fast curing cement concrete composition which comprises: 7-40 wt% of an early age strength development binder; 3-85 wt% of a fine aggregate; 7-75 wt% of a coarse aggregate; 0.5-30 wt% of a modifier; and 0.5-30 wt% of water, thereby improving workability in concrete.

Description

TECHNICAL FIELD [0001] The present invention relates to a cement-reduced quick-setting cement concrete composition, and a road pavement repairing and reinforcing method using the same.

The present invention relates to a crack-reducing ultra-lightweight cement concrete composition and a method for repairing and reinforcing road pavement using the same. More specifically, the present invention relates to a concrete cement composition for repairing and repairing pavement structures such as bridge bridge pavement, concrete pavement expansion, The present invention relates to a crack-reducing type quick-release cement concrete composition and a method of repairing and reinforcing road pavement using the same.

In general, cracks occur in concrete due to deterioration of performance of concrete structures, so that the compressive strength of concrete and the tensile strength of reinforcing bars gradually decrease during the period of public use, and the concrete exposed through the cracks is exposed to chlorine ion penetration, freezing and thawing, And corrosion of steel bars occurs. If these rebar corrosion phenomena become severe, the concrete structure may eventually collapse.

On the other hand, the use of ultra rapid cement has some problems from a long-term perspective. Concrete using quick-setting cement is effective for early strength development, but shrinkage due to heat and moisture movement in the structure is restrained by internal and external factors due to hydration heat and drying shrinkage relatively higher than ordinary portland cement at the early stage of curing, Cracks are likely to occur. These micro cracks increase the permeability in the concrete matrix and induce various types of fracture, which may directly affect the mechanical properties and durability of the structure, which may seriously affect the stability of the structure.

Generally, when a concrete structure is manufactured or packaged, cracks due to drying shrinkage occur, and laitance due to bleeding occurs on the surface, resulting in weak surface strength and durability.

On the other hand, when the concrete is cracked and the time passes, the compressive strength of the concrete and the tensile strength of the reinforcing bar gradually decrease, and the concrete exposed through the cracks is subjected to chlorine ion penetration, freezing and thawing, do. If these rebar corrosion phenomena become severe, the concrete structure may eventually collapse. In repairing such a concrete structure, a maintenance material excellent in strength and durability as that of a concrete-polymer composite is used because it can not secure required quality only by cementitious materials.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a crack-reducing ultra-lightweight cement concrete composition and a road pavement repairing and reinforcing method using the same.

In order to solve the above-described problems, the present invention provides a method for producing a steel sheet, which comprises 7 to 40% by weight of initial strength-generating binder, 3 to 85% by weight of fine aggregate, 7 to 75% by weight of coarse aggregate, 0.5 to 30% The present invention provides a crack-reduced ultra fast cement concrete composition comprising:

The initial strength-generating binder of the present invention is characterized by containing 10 to 90 wt% of crude steel portland cement, 5 to 50 wt% of magnesium sulfoaluminate, 1 to 30 wt% of amorphous calcium aluminate 1 to 30 wt% of silicon nitride, 1 to 20 wt% of gypsum, 1 to 20 wt% of emery powder, 0.5 to 10 wt% of calcium aluminate, and 0.5 to 10 wt% of lithium aluminate.

In addition, the initial strength-generating binder of the present invention preferably further comprises 0.01 to 10% by weight of oleic acid amide so as to be 100% by weight of the initial strength-generating binder in order to improve waterproofing, rust-inhibiting performance and shrinkage-reducing effect.

In addition, the initial strength-generating binder of the present invention preferably further comprises 0.01 to 10% by weight of sepiolite so as to be 100% by weight of the initial strength-generating binder in order to improve material separation prevention and water resistance.

In addition, the initial strength-generating binder of the present invention preferably further comprises 0.01 to 10% by weight of magnesium stearate so as to be 100% by weight of the initial strength-generating binder in order to improve stain resistance, corrosion resistance and oil resistance.

In addition, the initial strength-generating binder of the present invention is preferably a water-cement ratio of a crack-reducing ultra fast cement concrete composition so as to improve the strength and durability by reducing the water-cement ratio so that the total amount of the initial strength- To 10% by weight.

In addition, the initial strength-generating binder of the present invention is preferably used in an amount of 0.01 to 10 wt% of a hardening retarder so as to obtain a total of 100 wt% of the initial strength-generating binders in order to ensure workability for a certain period of time and to delay rapid curing. .

The modifier of the present invention may further contain, as a total amount of 100% by weight of the modifier, 30 to 95% by weight of polymethylmethacrylate, 1 to 30% by weight of an ethylene-vinyl alcohol copolymer, 1 to 30% by weight of a polyvinylidene fluoride- 25 wt% of polyphenylene oxide, 1 to 25 wt% of polyphenylene oxide, 1 to 25 wt% of methylvinyldimethoxysilane, 0.5 to 10 wt% of polycarboxylic acid-based water reducing agent, and 0.5 to 10 wt% of silicone-based defoaming agent.

In addition, the modifier of the present invention preferably further comprises 0.01 to 10% by weight of hexamethyldisilazane so as to have a total of 100% by weight of the modifier for improving the strength, adhesion and durability.

Further, the modifier of the present invention preferably further comprises 0.01 to 10% by weight of alkylene amide so that the total amount of the modifier is 100% by weight so as to reduce the drying shrinkage and reduce cracking.

The present invention also relates to a method for removing asphalt concrete using a road surface crusher, the method comprising the steps of: removing a concrete structure with deteriorated concrete or asphalt concrete using a road surface crusher; Removing the removed portion to a lower portion of the deteriorated portion by a planer, a short blaster, a water jet, a high pressure washer, a hand water jet, etc., and then cleaning the removed portion with a vacuum suction vehicle; A step of primer or blooming treatment on the cleaned part to improve the adhesion with the concrete concrete, reinforcement of surface layer, penetration of harmful substances, water, chlorine ion and the like and improve water resistance; Repairing or reinforcing a section of the deteriorated portion by installing the above-described crack-reducing ultra-lightweight cement concrete composition on the treated upper portion; The method comprising: performing longitudinal and transverse tinning to prevent slipping of the surface of the ultra-lightweight quick cement concrete composition; Applying a coating curing agent to prevent evaporation of water and suppress plastic cracking on the cement-reduced ultra-rapid cement concrete composition being tiled; And a curing step.

According to the present invention, the workability of concrete can be improved by using a modifier and an initial strength-generating binder, and the initial hydration of the cement by the hard material and the densification of the structure by the pozzolan reaction are promoted, Therefore, it is possible to improve the abrasion resistance and adhesion strength of concrete. Especially, by using the expanding material and the shrinkage reducing agent, the effect of preventing the initial plastic cracking and expansion fracture is obtained and the durability can be greatly improved. Therefore, all the characteristics required for concrete road pavement, namely, crack resistance, corrosion resistance, water tightness, adhesion and durability, can all be satisfied.

The crack-reducing ultra fast cement concrete composition of the present invention comprises 7 to 40% by weight of an initial strength-generating binder, 3 to 85% by weight of fine aggregate, 7 to 75% by weight of coarse aggregate, 0.5 to 30% by weight of modifier, 30% by weight.

Aggregates used in the present invention are classified into fine aggregates and coarse aggregates, and those having a particle diameter of 5 mm or less are called fine aggregates and those having a diameter larger than 5 mm are called coarse aggregates. The fine aggregate is preferably contained in an amount of 3 to 85% by weight based on the crack-reducing ultra fast cement concrete composition of the present invention, and the coarse aggregate is contained in an amount of 7 to 75% by weight based on the crack- desirable.

Wherein the initial strength-generating binder comprises 10 to 90 wt% of crude steel Portland cement, 5 to 50 wt% of magnesium sulfoaluminate, 1 to 30 wt% of amorphous calcium aluminate, 1 to 30 wt% of silicon nitride, 1 to 20 wt% 1 to 20% by weight of emulsion powder, 0.5 to 10% by weight of calcium aluminate, and 0.5 to 10% by weight of lithium aluminate.

The crude steel portland cement is preferably used as specified in KS, and is preferably contained in an amount of 10 to 90% by weight based on the initial strength-generating binder.

Preferably, the crude steel portland cement has a degree of powder of 3,000 to 5,000 cm 2 / g. When the powdery degree of the crude steel portland cement is less than 3,000 cm 2 / g, the reactivity is lowered and the initial strength development is delayed. When the powdery degree exceeds 5,000 cm 2 / g, the reactivity is increased, I am concerned.

When the weight ratio of magnesium sulfoaluminate is increased, quick curing characteristics are exhibited. The magnesium sulfoaluminate is preferably contained in an amount of 5 to 50% by weight based on the initial strength-generating binder. When the content of the magnesium sulfoaluminate is less than 5% by weight, the effect of improving the strength of the concrete and the effect of suppressing cracking may be insufficient. When the content of the magnesium sulfoaluminate exceeds 50% by weight, One is poor in workability and the manufacturing cost is not economical.

The amorphous calcium aluminate is used for initial strength development and shrinkage prevention. The amorphous calcium aluminate is used to prevent cracking of the concrete by tightening the texture and to prevent shrinkage of the concrete. The amorphous calcium aluminate is preferably contained in an amount of 1 to 30% by weight based on the initial strength-generating binder. The amorphous calcium aluminate exhibits fast curing properties as the weight ratio increases. When the content of the amorphous calcium aluminate is less than 1% by weight based on the initial strength-generating binder, the initial strength of the concrete and the effect of suppressing crack generation may be insignificant. When the content of the nate is more than 30% by weight, good physical properties can be obtained due to rapid curing characteristics, but the production cost is not high and it is not economical.

The silicon nitride is used for improving abrasion resistance, adsorptivity and fire resistance. The silicon nitride is preferably contained in an amount of 1 to 30% by weight based on the initial strength-generating binder, and when the content of the silicon nitride is more than 30% by weight, wear resistance and fire resistance are improved but workability may be deteriorated. If the content is less than 1% by weight, the performance improvement effect may be weak.

The gypsum is used for initial strength development and shrinkage prevention. The gypsum is used to prevent cracking of the concrete by making the structure dense and to prevent shrinkage of the concrete. The gypsum is preferably contained in an amount of 1 to 20% by weight based on the initial strength-generating binder. When the content of the gypsum is less than 1% by weight based on the initial strength-generating binder, the concrete strength and the effect of suppressing the occurrence of cracks may be insignificant. When the content of the gypsum exceeds 20% by weight, Physical properties can be obtained, but expansion and water resistance are lowered.

The emulsion powder has yellow, green, colorless and the like and is used for improving strength, abrasion resistance and fire resistance. The emulsion powder is preferably contained in an amount of 1 to 20% by weight based on the initial strength-generating binder. When the content of the emulsion powder is more than 20% by weight, abrasion resistance and fire resistance are improved but workability is deteriorated. If the content of the powder is less than 1% by weight, the workability is improved but the effect of improving the wear resistance and fire resistance may be weak.

The calcium aluminate is used to control the initial curing rate. The calcium aluminate is preferably contained in an amount of 0.5 to 10 wt% based on the initial strength-generating binding material. If the content of calcium aluminate is less than 0.5% by weight, the initial strength development is delayed. If the content of calcium aluminate exceeds 10% by weight, the reactivity is increased and the workability is lowered and the price competitiveness is lowered.

The lithium aluminate is used for improving long-term strength development, shrinkage reduction effect, water resistance, chemical resistance, and freeze-thaw resistance. The lithium aluminate is preferably contained in an amount of 0.5 to 10% by weight based on the initial strength-generating binder. If the content of lithium aluminate is less than 0.5% by weight, the performance improving effect may be deteriorated. If the content of lithium aluminate exceeds 10% by weight, workability is deteriorated and price competitiveness is deteriorated.

The initial strength-generating binding material may further include oleic acid amide. The oleic acid amide is used to improve the waterproofing, antirust performance and shrinkage reduction effect. The oleic acid amide is preferably contained in an amount of 0.01 to 10 wt% based on the initial strength-generating binder. If the content of oleic acid amide is less than 0.01 wt%, the performance improvement effect may be insufficient. When the content of oleic acid amide is more than 10 wt%, the performance improvement effect is excellent, but the workability and price competitiveness are deteriorated.

The initial strength-generating binder may further include sepiolite to prevent material separation and improve water resistance. The amount of the sepiolite is preferably 0.01 to 10% by weight based on the initial strength-generating binder. If the content of the sepiolite is less than 0.01% by weight, the effect of preventing the material separation and improving the water-proofing performance may be insignificant. If the content of the sepiolite exceeds 10% by weight, The strength expression is lowered.

The initial strength-generating binder may further include magnesium stearate to obtain strength, abrasion resistance, dispersibility, and water resistance. The magnesium stearate is preferably contained in an amount of 0.01 to 10 wt% based on the initial strength-generating binder. If the content of the magnesium stearate is less than 0.01% by weight, the effect of improving the strength, abrasion resistance, dispersibility and waterproofing performance is insufficient. If the content of the magnesium stearate exceeds 10% by weight, the material is easily separated and the manufacturing cost is high, Can not do it.

The initial strength-generating binding material may further include a water reducing agent. The water reducing agent is used to improve the strength and durability by reducing the water-cement ratio of the crack-reducing ultra fast cement concrete composition. As the water reducing agent, a polycarboxylic acid type, melamine type or naphthalene type water reducing agent may be used. The water reducing agent is preferably a naphthalene-based water reducing agent having an excellent effect of improving the strength and durability and having an excellent effect of reducing the water-cement ratio, and is preferably contained in an amount of 0.01 to 10% by weight based on the initial strength-

The initial strength-generating binder may further include a hardening retarder. The curing retarder can be used to ensure workability for a certain period of time and to delay rapid curing. The curing retarder is preferably contained in an amount of 0.01 to 10% by weight based on the initial strength-generating binder. As the hardening retarder, generally known substances can be used. Examples thereof include saccharides such as glucose, glucose, texturin, dextran, acids or salts thereof such as gluconic acid, malic acid, citric acid, aminocarboxylic acid, Salts, phosphonic acids or derivatives thereof, polyhydric alcohols such as glycerin, and the like.

It is preferable that the modifier is contained in 0.5 to 30% by weight in the crack-reducing ultra fast cement concrete composition. If the content of the modifier exceeds 30% by weight, the viscosity of the ultra-lightweight cementitious concrete composition of the present invention is lowered to improve the workability (slump), but the hydration reaction is delayed to lower the initial compressive strength, . If the content of the modifier is less than 0.5% by weight, the effect of improving the curing time, workability, strength and durability may be insignificant.

The modifier is used to improve the curing time, workability, strength and durability of the ultra low flexural cement concrete composition of the present invention. The modifier is composed of 30 to 95% by weight of polymethylmethacrylate, 1 to 30% by weight of ethylene- 1 to 25 wt% of polyvinylidene fluoride-acrylic copolymer, 1 to 25 wt% of polyphenylene oxide, 1 to 25 wt% of methylvinyldimethoxysilane, 0.5 to 10 wt% of polycarboxylic acid-based water reducing agent, 0.5 to 10% by weight of an antifoaming agent.

The polymethylmethacrylate is used to improve the bonding strength and endurance performance. The polymethyl methacrylate is preferably contained in an amount of 30 to 95% by weight based on the modifier. If the content of the polymethylmethacrylate exceeds 95% by weight, the workability is improved, but the initial strength development may be deteriorated. When the content of the polymethylmethacrylate is less than 30% by weight, the initial strength of the concrete is improved However, the workability is remarkably lowered.

The ethylene-vinyl alcohol copolymer is used to improve material separation resistance, adhesion strength and durability. The ethylene-vinyl alcohol copolymer is preferably contained in an amount of 1 to 30% by weight based on the modifier. If the content of the ethylene-vinyl alcohol copolymer is more than 30% by weight, the performance may be improved but the viscosity may be increased and the workability (slump) may be lowered. If the content of the ethylene-vinyl alcohol copolymer is less than 1% The separation resistance, the adhesion strength and the durability improvement effect may be weak.

The polyvinylidene fluoride-acrylic copolymer is used to improve strength, weather resistance, and durability. The polyvinylidene fluoride-acrylic copolymer is preferably contained in an amount of 1 to 25% by weight based on the modifier. When the content of the polyvinylidene fluoride-acrylic copolymer exceeds 25% by weight, If the content of the polyvinylidene fluoride-acrylic copolymer is less than 1% by weight, the effect of improving the strength and durability may be insignificant.

The polyphenylene oxide is used for improving strength, heat resistance and dimensional stability. The polyphenylene oxide is preferably contained in an amount of 1 to 25% by weight based on the modifier. If the content of the polyphenylene oxide is more than 25% by weight, the performance improving effect is not further developed and the price competitiveness may be lowered. If the content of the polyphenylene oxide is less than 1% by weight, workability, weather resistance, And the effect of improving the heat resistance may be insufficient.

The methylvinyldimethoxysilane is used to promote the reactivity and improve the strength and durability. The methylvinyl dimethoxysilane is preferably contained in an amount of 1 to 25% by weight based on the modifier. When the content of the methylvinyldimethoxysilane is less than 1% by weight, the performance improving effect is deteriorated. When the content exceeds 25% by weight, the strength and durability are improved, but the reactivity is promoted and the workability is lowered.

The polycarboxylic acid-based water reducing agent improves the strength and durability by reducing the water-cement ratio, and at the same time serves to improve the initial workability by delaying the hydration reaction of the crude steel cement. The polycarboxylic acid-based water reducing agent is preferably contained in an amount of 0.5 to 10% by weight based on the modifying agent.

The silicone-based defoaming agent is used for lowering the air amount and lowering the air gap to improve strength and durability. The silicone-based defoaming agent is preferably contained in an amount of 0.5 to 10 wt% based on the modifier.

In addition, the modifier may further include hexamethyldisilazane. The hexamethyldisilazane is used for strength, adhesion and durability improvement. The hexamethyldisilazane is preferably contained in an amount of 0.01 to 10% by weight based on the modifier. If the content of hexamethyldisilazane exceeds 10% by weight, the performance may be improved but the viscosity may be increased and the workability may be deteriorated. If the content of hexamethyldisilazane is less than 0.01% by weight, .

The modifier may further comprise an alkylene amide. The alkylene amide is used to reduce the occurrence of cracks by waterproofing, rust prevention and shrinkage reduction. The alkylene amide is preferably contained in an amount of 0.01 to 10 wt% based on the modifier. If the content of the alkylene amide exceeds 10 wt%, the drying shrinkage reducing effect is improved but the strength is lowered. When the content is less than 0.01% by weight, the performance improvement effect is insufficient.

The cement-based ultra low flexural cement concrete composition having improved durability according to the present invention comprises 7 to 40% by weight of initial strength-generating binder, 3 to 85% by weight of fine aggregate and 7 to 75% by weight of coarse aggregate in a forced mixer or continuous mixer , 0.5 to 30% by weight of a modifier and 0.5 to 30% by weight of water are further mixed and stirred for a predetermined time (for example, 1 to 10 minutes).

Hereinafter, a road pavement repairing method according to a preferred embodiment of the present invention will be described.

The method of repairing and reinforcing road pavement using a crack-reduced ultra-quick-lightweight cement concrete composition according to a preferred embodiment of the present invention comprises the steps of removing a portion of a concrete structure where the concrete is deteriorated or an asphalt concrete using a road surface crusher; Removing the removed portion to a lower portion of the deteriorated portion by a planer, a short blaster, a water jet, a high pressure washer, a hand water jet, etc., and then cleaning the removed portion with a vacuum suction vehicle; A step of primer or blooming treatment on the cleaned part to improve the adhesion with the concrete concrete, reinforcement of surface layer, penetration of harmful substances, water, chlorine ion and the like and improve water resistance; Repairing or reinforcing a section of the deteriorated portion by installing the above-described crack-reducing ultra-lightweight cement concrete composition on the treated upper portion; The method comprising: performing longitudinal and transverse tinning to prevent slipping of the surface of the ultra-lightweight quick cement concrete composition; Applying a coating curing agent to prevent evaporation of water and suppress plastic cracking on the cement-reduced ultra-rapid cement concrete composition being tiled; And curing.

The deteriorated portion may be removed to the lower portion of the reinforcing bar, and the rust of the exposed reinforcing bar may be removed before the primer or blooming. In the case of chipping using the crusher and the water jet, in the normal case, the reinforcing bars of the concrete structure are not exposed. However, when the deterioration is severe, the reinforcing bars may be exposed at the deteriorated portions. According to the invention, a separate rebar anti-rust treatment is not required.

According to the present invention, it is possible to improve the workability of the concrete by using the modifier and the initial strength-generating binding material, to improve the flexural strength and the adhesive strength of the concrete, to reduce the drying shrinkage amount, Especially abrasion resistance and water resistance.

(Example)

Hereinafter, embodiments of the crack-reducing ultra low speed cement concrete composition according to the present invention will be more specifically shown and the present invention is not limited by the following embodiments.

Example 1

39 kg of crude steel Portland cement, 30 kg of magnesium sulfoaluminate, 10 kg of amorphous calcium aluminate, 5 kg of silicon nitride, 5 kg of gypsum, 5 kg of emery powder, 1 kg of calcium aluminate, 1 kg of lithium aluminate, 1 kg of oleic acid amide, 1 kg of sepiolite, 1 kg of magnesium stearate, 0.5 kg of a polycarboxylic acid-based water reducing agent and 0.5 kg of a citric acid-based curing retarder were mixed to obtain 100 kg of an initial strength-inducing binding material.

Separately, 92 kg of polymethylmethacrylate, 2 kg of ethylene-vinyl alcohol copolymer, 1 kg of polyvinylidene fluoride-acrylic copolymer, 1 kg of polyphenylene oxide, 1 kg of methylvinyldimethoxysilane, 0.5 kg of a water reducing agent, 0.5 kg of a silicone antifoam agent, 1 kg of hexamethyldisilazane and 1 kg of an alkylene amide were mixed to obtain 100 kg of a modifier.

20 kg of the initial strength-generating binder obtained above, 39 kg of fine aggregate, and 31 kg of coarse aggregate were put into a forced mixer and stirred. Then, 6 kg of the modifier obtained above and 4 kg of water were further mixed, , 100 kg of a crack-reduced ultra fast cement concrete composition of the present invention was prepared.

Example 2

45 kg of crude steel Portland cement, 25 kg of magnesium sulfoaluminate, 12 kg of amorphous calcium aluminate, 4 kg of silicon nitride, 4 kg of gypsum, 4 kg of emery powder, 1 kg of calcium aluminate, 1 kg of lithium aluminate, 1 kg of oleic acid amide, 1 kg of sepiolite, 1 kg of magnesium stearate, 0.5 kg of a polycarboxylic acid-based water reducing agent and 0.5 kg of a citric acid-based curing retarder were mixed to obtain 100 kg of an initial strength-inducing binding material.

Separately, 86 kg of polymethylmethacrylate, 3 kg of ethylene-vinyl alcohol copolymer, 2 kg of polyvinylidene fluoride-acrylic copolymer, 2 kg of polyphenylene oxide, 2 kg of methylvinyldimethoxysilane, 2 kg of silazane, 2 kg of alkylene amide, 0.5 kg of polycarboxylic acid type water reducing agent and 0.5 kg of silicone antifoaming agent were mixed to obtain 100 kg of a modifier.

25 kg of the initial strength-generating binder obtained above, 35 kg of fine aggregate, and 30 kg of coarse aggregate were put into a forced mixer and stirred. Then, 5 kg of the modifier obtained above and 5 kg of water were further mixed, , 100 kg of a crack-reduced ultra fast cement concrete composition of the present invention was prepared.

Example 3

50 kg of crude steel Portland cement, 20 kg of magnesium sulfoaluminate, 10 kg of amorphous calcium aluminate, 5 kg of silicon nitride, 5 kg of gypsum, 4 kg of emery powder, 1 kg of calcium aluminate, 1 kg of lithium aluminate, 1 kg of oleic acid amide, 1 kg of sepiolite, 1 kg of magnesium stearate, 0.5 kg of a polycarboxylic acid-based water reducing agent and 0.5 kg of a citric acid-based curing retarder were mixed to obtain 100 kg of an initial strength-inducing binding material.

Separately, 80 kg of polymethylmethacrylate, 4 kg of ethylene-vinyl alcohol copolymer, 3 kg of polyvinylidene fluoride-acrylic copolymer, 3 kg of polyphenylene oxide, 3 kg of methylvinyldimethoxysilane, 0.5 kg of a water reducing agent, 0.5 kg of a silicone antifoam, 3 kg of hexamethyldisilazane and 3 kg of alkylene amide were mixed to obtain 100 kg of a modifier.

30 kg of the initial strength-generating binder obtained above, 30 kg of fine aggregate, and 30 kg of coarse aggregate were put into a forced mixer and stirred. Then, 6 kg of the modifier obtained above and 4 kg of water were further mixed, , 100 kg of a crack-reduced ultra fast cement concrete composition of the present invention was prepared.

(Comparative Example)

In order to more easily grasp the characteristics of the first to third embodiments according to the present invention, comparative examples which can be compared with the embodiments of the present invention are shown. Comparative example 1 to be described later is a conventional Speed cement concrete composition.

Comparative Example 1

20 kg of cement at the first speed, 39 kg of fine aggregate and 31 kg of coarse aggregate were put into a forced mixer and stirred. Then, 6 kg of polymethylmethacrylate and 4 kg of water were further mixed and further stirred for 2 minutes to prepare a rapid cement concrete composition 100 kg. At this time, 0.5 kg of a citric acid retarder was mixed with the quick-setting cement.

(Test Example)

The following test examples compares the characteristics of the example of the present invention and the characteristics of the comparative example 1 in order to more easily grasp the characteristics of the embodiments 1 to 3 according to the present invention, and the experimental results are shown in the table.

≪ Test Example 1 >

(Slump change test over time)

The crack-reduced ultra-rapid cement concrete composition prepared according to Examples 1 to 3 of the present invention and the quick-setting cement concrete composition prepared according to Comparative Example 1 were subjected to a slump test The results are shown in Table 1 below. The slump test is to test the quality of the dough such as the flue and viscosity of the concrete. The larger the value, the better the workability in putting the concrete.

division Slump (cm) Immediately after stirring After 20 minutes After 30 minutes After 40 minutes Example 1 19 17 14 10 Example 2 19 17 14 11 Example 3 21 19 16 14 Comparative Example 1 19 16 12 7

As shown in Table 1, the crack-reduced ultra-lightweight cement concrete composition prepared according to Examples 1 to 3 of the present invention had a workability after 20 minutes compared to the ultra fast cement concrete composition prepared according to Comparative Example 1 In particular, the crack-reduced quick-setting cement concrete composition produced according to Example 3 has excellent workability because the change in slump is not large even after a lapse of time.

≪ Test Example 2 &

(Test of change in compressive strength with time)

The compressive strength test of the crack-reduced ultra-quick-cement concrete composition prepared according to Examples 1 to 3 of the present invention and the quick-setting cement concrete composition prepared according to Comparative Example 1 was performed by KS F 2405, Are shown in Table 2 below.

division Compressive strength (N / mm ² ) After 4 hours After 1 day After 7 days After 28 days Example 1 30.0 36.5 41.5 45.0 Example 2 31.2 37.5 43.0 46.8 Example 3 31.8 39.5 44.2 48.9 Comparative Example 1 27.0 33.5 38.5 42.0

As shown in Table 2, the crack-reduced ultra-rapid cement concrete composition prepared according to Examples 1 to 3 of the present invention had significantly higher compressive strength than the quick-setting cement concrete composition prepared according to Comparative Example 1. [

≪ Test Example 3 >

(Change test of bending strength with time)

The flexural strengths of the crack-reduced ultra fast cement concrete compositions prepared according to Examples 1 to 3 of the present invention and the ultra rapid cement concrete compositions prepared according to Comparative Example 1 were measured by KS F 2408, Table 3 shows the results.

division Bending strength (N / mm ² ) After 4 hours After 1 day After 7 days After 28 days Example 1 5.3 5.8 6.5 7.1 Example 2 5.5 6.1 7.1 7.5 Example 3 5.6 6.5 7.3 7.9 Comparative Example 1 4.3 5.2 6.0 6.6

As shown in Table 3, the crack-reduced ultra-lightweight cement concrete composition produced according to Examples 1 to 3 of the present invention had significantly higher flexural strength than the quick-setting cement concrete composition prepared according to Comparative Example 1.

<Test Example 4>

(Test of adhesion strength with time)

The adhesive strength of the crack-reduced ultra fast cement concrete composition prepared according to Examples 1 to 3 of the present invention and the polymer cement concrete composition prepared according to Comparative Example 1 were measured by KS F 2762, Table 4 shows the results.

division Adhesion strength (N / mm ² ) After 4 hours After 1 day After 7 days After 28 days Example 1 1.55 1.6 1.85 2.0 Example 2 1.68 1.65 1.9 2.1 Example 3 1.61 1.71 1.95 2.2 Comparative Example 1 1.45 1.53 1.72 1.82

As shown in Table 4, the crack-reduced ultra fast cement concrete composition prepared according to Examples 1 to 3 of the present invention had significantly higher adhesive strength than the ultra fast cement concrete composition prepared according to Comparative Example 1.

&Lt; Test Example 5 >

(Test of rate of change of concrete length)

The rate of change in length was measured by KS F 2424 using the crack-reduced ultra fast cement concrete composition prepared according to Examples 1 to 3 of the present invention and the ultra fast cement concrete composition prepared according to Comparative Example 1, Are shown in Table 5 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Length change rate (%) 0.005 0.003 0.0023 0.013

As shown in Table 5, when the crack-reduced ultra-rapid cement concrete composition prepared according to Examples 1 to 3 of the present invention had a length change rate of 50% or more as compared with the ultra fast cement concrete composition prepared according to Comparative Example 1 And the shrinkage reduction effect was excellent.

&Lt; Test Example 6 >

(Neutralization resistance test)

The cement-reduced quick-setting cement concrete composition prepared according to Examples 1 to 3 of the present invention and the quick-setting cement concrete composition prepared according to Comparative Example 1 were subjected to a neutralization resistance test by KS F 4042, Shown in Table 6 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Neutralization depth (mm) 0.15 0.12 0.08 0.3

As shown in Table 6, the crack-reduced ultra-rapid cement concrete composition produced according to Examples 1 to 3 of the present invention had a lower neutralization depth than that of the quick-setting cement concrete composition prepared according to Comparative Example 1, And that the resistance to

&Lt; Test Example 7 >

(Chloride ion penetration resistance test)

The chloride-cemented quick-setting cement concrete composition prepared according to Examples 1 to 3 of the present invention and the quick-setting cement concrete composition prepared according to Comparative Example 1 were tested for chloride ion penetration resistance by KS F 4042, The results are shown in Table 7 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Chloride ion penetration resistance (coulombs) 620 580 540 780

As shown in Table 7, the crack-reduced ultra-rapid cement concrete composition produced according to Examples 1 to 3 of the present invention had a resistance to chloride ion penetration compared to the fast curing concrete composition prepared according to Comparative Example 1 Was high.

<Test Example 8>

(Freeze-thaw resistance test)

The crack-reduced ultra fast cement concrete composition prepared according to Examples 1 to 3 of the present invention and the ultra fast cement concrete composition prepared according to Comparative Example 1 were subjected to a resistance test for freezing and thawing with KS F 2456 , And the results are shown in Table 8 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Freeze-thaw
Resistance (%) 89 90 91 84

As shown in Table 8, the crack-reduced ultra-rapid cement concrete composition prepared according to Examples 1 to 3 of the present invention has excellent freeze-thaw resistance as compared with the ultra fast cement concrete composition prepared according to Comparative Example 1 Could know.

&Lt; Test Example 9 >

(Abrasion Resistance Test)

The ultra low speed cement concrete composition according to Examples 1 to 3 of the present invention and the ultra low speed cement concrete composition prepared according to Comparative Example 1 were subjected to the abrasion resistance test according to ASTM C 779, Are shown in Table 9 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Abrasion Resistance (mm) 0.04 0.02 0.01 0.08

As shown in Table 9, it was found that the crack-reduced ultra-lightweight cement concrete composition prepared according to Examples 1 to 3 of the present invention had higher abrasion resistance than that of the quick-setting cement concrete composition prepared according to Comparative Example 1 I could.

&Lt; Test Example 10 &

(Chemical resistance test by immersion of concrete in solution)

The cement-reduced quick-setting cement concrete composition prepared according to Examples 1 to 3 of the present invention and the quick-setting cement concrete composition prepared according to Comparative Example 1 were mixed with 2% hydrochloric acid, 5% sulfuric acid, The aqueous solution of 45% sodium hydroxide was immersed in the test solution for 28 days, and the chemical resistance test was carried out. The measurement results are shown in Table 10 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Weight change rate
(%) Hydrochloric acid -0.8 -0.55 -0.45 -1.3 Sulfuric acid -0.06 0 0 -0.12 Sodium hydroxide +0.7 +1.1 +1.2 +0.2

As shown in Table 10 above, the crack-reduced ultra-rapid cement concrete composition produced according to Examples 1 to 3 of the present invention had a weight against chemical resistance as compared with the ultra fast cement concrete composition prepared according to Comparative Example 1 The rate of change was small and it was confirmed that the resistance to chemical resistance was high.

&Lt; Test Example 11 &

(Rust prevention rate test)

In order to compare the characteristics of the ultra low speed cement concrete composition with crack reduction type prepared according to Examples 1 to 3 of the present invention and the ultra rapid cement concrete composition prepared according to Comparative Example 1, KS F 2561 (anti- ), And the results are shown in the following Table 11. &lt; tb &gt; &lt; TABLE &gt;

division Example 1 Example 2 Example 3 Comparative Example 1 Rust prevention rate (%) 96 97.0 98 92

As shown in Table 11 above, the crack-reduced ultra-rapid cement concrete composition produced according to Examples 1 to 3 of the present invention had less rusting rate than the quick-setting cement concrete composition prepared according to Comparative Example 1 It was confirmed that the anti-rust effect was high.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, This is possible.

Claims (11)

A cement-reduced quick-setting cement concrete comprising 7 to 40% by weight of initial strength-generating binder, 3 to 85% by weight of fine aggregate, 7 to 75% by weight of coarse aggregate, 0.5 to 30% by weight of modifier, and 0.5 to 30% As a composition,
Wherein the initial strength-generating binder is 10 to 90% by weight of crude steel portland cement, 5 to 50% by weight of magnesium sulfoaluminate, 1 to 30% by weight of amorphous calcium aluminate, 1 to 30% by weight of silicon nitride 1 1 to 20% by weight of gypsum, 1 to 20% by weight of emery powder, 0.5 to 10% by weight of calcium aluminate, and 0.5 to 10% by weight of lithium aluminate; And
Wherein the modifier comprises 30 to 95% by weight of polymethylmethacrylate, 1 to 30% by weight of an ethylene-vinyl alcohol copolymer, 1 to 25% by weight of a polyvinylidene fluoride-acrylic copolymer, Characterized in that it comprises 1 to 25% by weight of phenylene oxide, 1 to 25% by weight of methylvinyldimethoxysilane, 0.5 to 10% by weight of polycarboxylic acid-based water reducing agent and 0.5 to 10% Cement concrete composition.
delete 3. The composition of claim 1, further comprising 0.01 to 10% by weight of oleic acid amide, sepiolite, magnesium stearate, water reducing agent or curing retarder such that the initial strength-generating binder is 100% Wherein the cementitious material is a cementitious material.
delete delete delete delete delete The crack-reducing ultra-lightweight cementitious concrete composition according to claim 1, further comprising 0.01 to 10% by weight of hexamethyldisilazane or alkylene amide so that the modifier is 100% by weight of the modifier.
delete A method of repairing and reinforcing road pavement using a crack-reduced type quick-release cement concrete composition according to claim 1,
Removing the asphalt concrete or the concrete where the concrete structure is deteriorated by using the road surface crusher;
Removing the removed portion to a lower portion of the deteriorated portion by a planer, a short blaster, a water jet, a high pressure washer, a hand water jet, etc., and then cleaning the removed portion with a vacuum suction vehicle;
A step of primer or blooming treatment on the cleaned part to improve the adhesion with the concrete concrete, reinforcement of surface layer, penetration of harmful substances, water, chlorine ion and the like and improve water resistance;
Repairing or reinforcing a section of the deteriorated portion by installing the crack-reduced ultra fast cement concrete composition on the treated portion;
The method comprising: performing longitudinal and transverse tinning to prevent slipping of the surface of the ultra-lightweight quick cement concrete composition;
Applying a coating curing agent to prevent evaporation of water and suppress plastic cracking on the cement-reduced ultra-rapid cement concrete composition being tiled; And
And curing. The method of repairing and reinforcing road pavement by using a crack-reducing type quick-release cement concrete composition.