KR101991420B1 - Cement Mortar Composition For Emergency Repair With Improved Strength and Durability And Method For Repairing And Reinforcing Concrete Structure Using The Same - Google Patents

Abstract

The present invention relates to a cement mortar composition for emergency repair with improved strength and durability, and to a method for repairing and reinforcing a concrete structure using the same. The cement mortar composition for emergency repair of the present invention comprises 10 to 80 wt% of a fast hardening modified binder, 15 to 85 wt% of a fine aggregate, and 5 to 30 wt% of water.

Description

Technical Field [0001] The present invention relates to a cement mortar composition for emergency repair, which has improved strength and durability, and a method for repairing and reinforcing a concrete structure using the same.

The present invention relates to a cement mortar composition for emergency repair having improved strength and durability and a method for repairing and reinforcing concrete structures using the same. More particularly, the present invention relates to a cement mortar composition for repairing and reinforcing concrete structures, The present invention relates to a cement mortar composition for emergency repair, which is improved in strength and durability, capable of extending the durability of concrete structures, reducing maintenance cost, and improving workability, and having excellent durability such as flame retardancy, And a method of repairing and reinforcing concrete structures used.

In general, cracks in concrete are caused by various factors such as external environmental causes such as deterioration, deterioration, material properties such as design load, plastic shrinkage or drying shrinkage, mixing conditions, and construction factors.

If cracks occur in the concrete structure due to various factors such as this, the concrete structure can not withstand the load and may collapse. Therefore, in order to recover the waterproofness and durability of the cracked concrete structure, It is necessary to repair it.

On the other hand, chemical corrosion of concrete means change of concrete by a certain chemical reaction. It brings about degradation of hydrate. It is the action of microorganisms with organic inorganic acid, animal and vegetable oil, corrosive gas, carbon dioxide gas and sulfuric acid. . In addition, there are animal and vegetable oils, sulphates, seawater, and alkali-enriched solutions to produce an expandable compound, and the paste is made porous by dissolution and desorption of the hydrate, which means the action of concentrated chloride and nitrate solutions.

Generally, there is a disadvantage in that when the concrete structure is manufactured or packaged, cracks are generated due to drying shrinkage, and the surface of the concrete structure is subjected to levitation due to bleeding, resulting in weak surface strength and durability.

On the other hand, polymer cement mortar is widely used for maintenance and reinforcement of areas where the bottom plate of a bridge, the road surface and the lower part of the bridge are corroded or eroded. The cement of the fast speed cement has the advantage of quick curing time and early strength development as compared with the Portland cement. On the other hand, the penetration of chloride or moisture causes the concrete to be corroded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a steel sheet which can improve fluidity, bending strength, tensile strength, adhesion strength, flexural toughness, weatherability, salt resistance, The present invention provides a cement mortar composition for an emergency repair having improved strength and durability that can shorten a construction time and shorten a traffic opening time, and a method for repairing and reinforcing a concrete structure using the same.

As a result of studying the above problems, the present inventors have found out that the above-mentioned problems can be solved by making a specific constitution, and have accomplished the present invention.

That is, the gist of the present invention is an emergency cement mortar composition comprising 10 to 80 wt% of a quick hardening modified binder, 15 to 85 wt% of a fine aggregate, and 5 to 30 wt% of water, The present invention provides an emergency repair cement mortar composition which comprises 15 to 85% by weight of crude steel Portland cement, 2 to 40% by weight of magnesium or calcium sulfoaluminate, 2 to 40% by weight of alumina cement 2 2 to 20 wt% of meta kaolin, 2 to 20 wt% of emery powder, 2 to 15 wt% of gypsum, 1 to 15 wt% of stellite, 1 to 15 wt% of zink chromite, 1 to 15 wt% of strontium aluminate, 0.5 to 10% by weight of styrene-butylacrylate copolymer, 0.5 to 10% by weight of fluorine silane, and 0.5 to 10% by weight of bakelite.

Another point of the present invention is that the quick hardening reforming material comprises at least one component selected from the group consisting of a hydro-bentonite methyl cellulose mixture, a polypropylene glycol, a curing retarder, and a defoaming agent based on 100 wt% The present invention also provides a cement mortar composition for emergency repair, which further comprises 0.01 to 10 wt%.

Another object of the present invention is to provide a thermosetting resin composition which comprises at least one material selected from the group consisting of polypropylene fiber, polyester fiber, nylon fiber and macro fiber to improve flexural and tensile strength, initial plastic cracking and fracture toughness The present invention also provides a cement mortar composition for emergency repair, which further comprises 0.01 to 10 wt%.

The present invention is further characterized in that the quick-hardening modified binder further comprises 0.01 to 10% by weight of a mixture of a polycarboxylic acid-based water reducing agent and a melamine sulfonic acid based water reducing agent in a weight ratio of 1: 0.01 to 0.8 To provide a cement mortar composition.

Another object of the present invention is to provide a cement mortar composition for emergency repair characterized in that the fine aggregate is silica sand mixed with silica sand No. 4: No. 6 silica in a weight ratio of 0.1 to 0.45: 0.55: 0.9.

Another aspect of the present invention is to provide a method of repairing and reinforcing a concrete structure including the following steps:

Chipping the impurity or deteriorated portion of the concrete structure with a grinder, a planer, or a shot blaster;

Cleaning the chipped portion with a hand water jet, a vacuum inhaler or the like;

A primer or blooming treatment for improving the adhesion of the concrete concrete and the cement mortar composition for emergency repair, suppressing foreign matter penetration, and improving water resistance and waterproofing property;

Placing the emergency cement mortar composition according to the present invention on the primer or the blooming treated upper part using a spraying equipment;

Surface-finishing the surface with a trowel or a sponge before the applied composition is completely cured; And

Applying a protective coating on top of a surface finish to improve resistance to salt, neutralization resistance and durability, and curing.

The cement mortar composition for emergency repair of the present invention can improve workability and workability, improve toughness and adhesion strength, reduce shrinkage and prevent shrinkage cracking and improve durability. In addition, hydration and densification of internal structure can be promoted by pozzolanic reaction, and a closed mortar can be made, thereby improving strength and durability, particularly water resistance and corrosion resistance. Further, by using the expanding material and the shrinkage reducing agent, an effect of preventing surface cracking and expansion / fracture due to drying shrinkage can be obtained.

According to the repair method of the concrete structure using the emergency repair cement mortar composition of the present invention, since the emergency repair cement mortar composition is a one packaged type in powder form, it can be used by mixing only water in the field, Time saving and on-site quality control are excellent, and workability can be improved. In addition, it is possible to shorten the construction period by short-time type, shorten the traffic opening time (2 to 4), extend the use period of the structure, reduce the maintenance cost, To reduce the cost of extending the public service and maintenance.

Hereinafter, preferred embodiments according to the present invention will be described in detail. However, it will be understood by those skilled in the art that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various changes and modifications may be made without departing from the scope of the present invention. It is not.

Hereinafter, the concrete structure means a concrete structure such as a bridge slab, a road surface, a bridge pavement, a road facility structure (a central separation wall, a wing wall, a side wall concrete, an underground road, a retaining wall, It is used for the meaning of all structures made of concrete including structures (agricultural waterways, aqueducts, etc.), chemical facilities, and offshore structures.

The cement mortar composition for emergency repair according to a preferred embodiment of the present invention comprises 10 to 80 wt% of a quick hardening modified binder, 15 to 85 wt% of fine aggregate, and 5 to 30 wt% of water.

It is preferable that the quick hardening modified filler is contained in an amount of 10 to 80% by weight based on 100% by weight of the total amount of the cement mortar composition for emergency repair.

The fine aggregate used in the present invention is preferably contained in an amount of 15 to 85% by weight based on 100% by weight of the total amount of the cement mortar composition for emergency repair. Aggregates are classified into fine aggregate and coarse aggregate. Hereinafter, those having a grain size of 5 mm or less are called fine aggregate. The fine aggregate is preferably silica sand mixed with silica sand No. 4: No. 6 in a weight ratio of 0.1 to 0.45: 0.55: 0.9.

Wherein the quick hardening modified filler comprises 15 to 85% by weight of crude steel Portland cement, 2 to 40% by weight of magnesium or calcium sulfoaluminate, 2 to 20% by weight of alumina cement, 2 to 20 wt% of emulsion powder, 2 to 15 wt% of gypsum, 1 to 15 wt% of stellite, 1 to 15 wt% of zinc chromate, 1 to 15 wt% of strontium aluminate, 0.5 to 10% by weight of styrene-acrylic acid ester copolymer, 0.5 to 10% by weight of styrene-butyl acrylate copolymer, 0.5 to 10% by weight of fluorine silane and 0.5 to 10% by weight of bakelite.

 The quick-setting reforming material may further contain 0.01 to 10 wt% of a hydro bentonite methyl cellulose mixture to prevent material separation.

In addition, the quick-setting modified binder may further contain 0.01 to 10 wt% of polypropylene glycol to reduce drying shrinkage.

The quick hardening modified filler may further contain 0.01 to 10% by weight of a hardening retarder for delaying rapid curing, based on 100% by weight of the quick hardening modified filler.

In order to improve the warpage and tensile strength, initial plastic cracking and fracture toughness, the quick hardening modified binder preferably contains 0.01 to 10% by weight of at least one material selected from polypropylene fiber, polyester fiber, nylon fiber and macro fiber .

In addition, the quick hard modifying binder may be a mixture of a polycarboxylic acid-based water reducing agent and a melamine sulfonic acid based water reducing agent in a weight ratio of 1: 0.01 to 0.8 in order to improve the watertightness and freeze-thaw resistance and improve durability by tightening the internal structure of the cement- By weight based on the total weight of the composition.

In addition, the quick hard modifying binder may further contain 0.01 to 10% by weight, based on 100% by weight of the total amount of the quick hardening modified binder, of a defoaming agent for reducing an increase in the amount of air due to the issuance of air to be delivered.

In addition, the quick hard modifying material may further include 0.01 to 10% by weight of pigment for realizing hue on the basis of a total of 100% by weight of the quick hard modifying binder and improving the appearance.

In the quick-hardening reformed binder of the present invention, the crude steel portland cement is preferably the one specified in KS, and the crude steel portland cement circulated in the market can be used. The crude steel portland cement preferably contains 15 to 85% by weight based on 100% by weight of the quick-hardening modified binder.

The magnesium or calcium sulfoaluminate and the alumina cement are mineral based ultra rapid curing materials which, when mixed with cement, enable the compression strength of ordinary Portland cement to be obtained within a few hours or days. The magnesium or calcium sulfoaluminate and the alumina cement are preferably contained in an amount of 2 to 40% by weight and 2 to 20% by weight, respectively, based on 100% by weight of the quick-hardening modified binder. If the content of the magnesium or calcium sulfoaluminate and alumina cement is less than 2% by weight, initial strength development and durability performance may be insufficient. If the content of the two components exceeds 60% by weight, workability and price competitiveness Can be degraded.

The meta kaolin is used for improving pozzolanic characteristics, long-term strength development and durability. When the weight ratio of the meta-kaolin powder is increased, the early strength is lowered, but the long-term strength development and durability are increased. The meta kaolin is preferably contained in an amount of 2 to 20% by weight based on 100% by weight of the quick-hardening modified binder. If the content of the meta kaolin exceeds 20 wt%, the durability improves but the early strength development deteriorates. If the content is less than 2 wt%, the effect of improving the long-term strength and durability is insufficient.

The emery powder is used for improving abrasion resistance, corrosion resistance, chemical resistance, heat resistance and the like. The emulsion powder is preferably contained in an amount of 2 to 20% by weight based on 100% by weight of the quick-hardening modified binder. When the content of the emulsion powder is less than 2% by weight, the effect of improving abrasion resistance, corrosion resistance, chemical resistance and heat resistance may be insignificant. When the content is more than 20% by weight, performance is improved but workability is decreased.

The gypsum is used for initial strength development. The gypsum can be anhydrous gypsum or anthracite. As the content of gypsum increases, it shows fast curing properties. The gypsum is preferably contained in an amount of 2 to 15% by weight based on 100% by weight of the total of the fast-hardening modified binders. If the content of the gypsum is less than 2% by weight, the initial strength development effect may be insufficient. If the content of the gypsum exceeds 15% by weight, workability and water resistance may be lowered.

The stellite is used to improve the strength, abrasion resistance and chemical resistance of the composition. It is preferable that the stellite is contained in an amount of 1 to 15% by weight based on 100% by weight of the total of the fast hardening modified binders. If the content of the stellite is less than 1 wt%, the performance improvement effect may be insufficient. If the content exceeds 15 wt%, the performance may be improved but the workability and water resistance may be deteriorated.

The zinc chromite can be used to improve strength and corrosion resistance. The zinc chromate is preferably contained in an amount of 1 to 15% by weight based on 100% by weight of the total amount of the quick hardening modified binder. As the weight ratio of zinc chromate increases, strength and corrosion resistance are exhibited. However, when the content is more than 15% by weight, the strength development is lowered and the production cost is increased and it is not economical. When the content is less than 1% Corrosion resistance effect may be weak.

The strontium aluminate is used for increasing the reactivity of the composition to express early strength. It is preferable that the strontium aluminate is contained in an amount of 1 to 15% by weight based on 100% by weight of the total of the quick hard modifying binders. As the weight ratio of the strontium aluminate increases, the early strength is exhibited. However, when the content is more than 15 wt%, the workability is deteriorated. When the content is less than 1 wt%, the early strength development effect may be weak.

The ethylene-vinyl acetate-acrylic acid ester copolymer not only improves warpage, tensile and adhesion strength, but also improves water resistance, alkali resistance and weather resistance. The ethylene-vinyl acetate-acrylate copolymer is preferably contained in an amount of 0.5 to 10% by weight based on 100% by weight of the total of the quick-hardening modified binders. If the content of the ethylene-vinyl acetate-acrylate copolymer is less than 0.5% by weight, the effect of improving the strength and durability is deteriorated. If the content exceeds 10% by weight, the improvement effect is obvious but the workability and economical efficiency are poor.

The styrene-butyl acrylate copolymer is added to improve strength and durability. The styrene-butylacrylate copolymer is preferably contained in an amount of 0.5 to 10% by weight based on 100% by weight of the total of the quick-hard modifying binders. When the content of the styrene-butylacrylate copolymer is less than 0.5% by weight, the strength and durability are deteriorated. When the content of the styrene-butylacrylate copolymer is more than 10% by weight, the performance is improved but the workability is likely to deteriorate.

The fluorine silane improves the reactivity to improve the strength and durability, thereby preventing dropout after adhesion. It is preferable that the fluorine silane is contained in an amount of 0.5 to 10% by weight based on 100% by weight of the total of the quick hard modifying materials. If the content of the fluorine silane is less than 0.5% by weight, the strength and durability are deteriorated. If the content exceeds 10% by weight, the viscosity is lowered and the material is likely to be separated.

The bakelite is added to improve strength and durability. The bakelite is preferably contained in an amount of 0.5 to 10% by weight based on 100% by weight of the total amount of the quick hardening modified binder. If the content of bakelite is less than 0.5 wt%, the effect of improving the strength and durability is insufficient. If the content of bakelite is more than 10 wt%, the viscosity is lowered and the material separation phenomenon tends to occur.

The cement mortar composition for emergency repair according to the present invention may further include a mixture of hydro-bentonite methylcellulose to prevent material separation and improve water resistance. The hydro-bentonite methyl cellulose mixture is preferably contained in an amount of 0.01 to 10% by weight based on 100% by weight of the total of the quick-hard modifying binders. When the content of the hydro-bentonite methyl cellulose mixture is less than 0.01% by weight, the water resistance is lowered and the material separation is likely to occur. When the content exceeds 10% by weight, viscosity increases and workability is lowered.

In addition, the cement mortar composition for emergency repair of the present invention may further comprise polypropylene glycol to reduce drying shrinkage and to prevent shrinkage cracking. The polypropylene glycol is preferably contained in an amount of 0.01 to 10% by weight based on 100% by weight of the total of the fast-hardening modified binders. If the content of the polypropylene glycol is less than 0.01% by weight, the effect of reducing cracks is insufficient. If the content exceeds 10% by weight, the strength may be lowered.

Further, in order to improve the flexural strength, tensile strength, initial plastic cracking and fracture toughness of the cement mortar composition for emergency repair of the present invention, at least one of polypropylene fiber, polyethylene fiber, nylon fiber and macro fiber is added As shown in FIG. It is preferable that at least one of the polypropylene fiber, the polyethylene fiber, the nylon fiber and the macro fiber is contained in an amount of 0.01 to 10 wt% based on 100 wt% of the total of the quick hard modifying binders. If the content of at least one of the polypropylene fiber, the polyethylene fiber, the nylon fiber and the macro fiber is less than 0.01% by weight, the effect of strength development and the effect of preventing cracking may be weak. If the content is more than 10% And water resistance may be deteriorated.

The cement mortar composition for emergency repair according to the present invention may further comprise a mixture of a polycarboxylic acid-based water reducing agent and a melamine sulfonic acid based water reducing agent to improve watertightness, freeze-thaw resistance and durability by making the internal structure of the cement- have. The polycarboxylic acid-based water reducing agent and the melamine sulfonic acid-based water reducing agent mixture are mixed in a weight ratio of 1: 0.01 to 0.8. The polycarboxylic acid-based water reducing agent and the melamine sulfonic acid-based water reducing agent mixture are preferably contained in an amount of 0.01 to 10% by weight based on 100% by weight of the quick-hardening modified binder.

The defoamer added to the cement mortar composition for emergency repair of the present invention is used for improving the strength and durability by reducing the increase of the amount of air due to the generation of the running air. As the antifoaming agent, generally known substances such as alcohol type defoaming agent, silicone type defoaming agent, fatty acid defoaming agent, oil type defoaming agent, ester type defoaming agent, oxyalkylene type defoaming agent and the like can be used. Examples of the silicone defoaming agent include dimethyl silicone oil, polyorganosiloxane, and fluorosilicone oil. Examples of the fatty acid defoaming agent include stearic acid and oleic acid. Examples of the oil-based antifoaming agent include kerosene, animal and plant oil, castor oil, and the ester-based antifoaming agents include solitol trioleate and glycerol monoricinolate. Examples of the oxyalkylene antifoaming agents include polyoxyalkylene, acetylene ethers, polyoxyalkylene diazoxide esters, and polyoxyalkylene alkylamines. Examples of the alcohol type antifoaming agent include glycol. The antifoaming agent is preferably contained in an amount of 0.01 to 10% by weight based on 100% by weight of the total of the quick-hardening modified binders.

The curing retarder added in addition to the composition of the present invention is used for delaying rapid curing in order to secure workability for a certain period of time. The curing retarding agent is added in an amount of 0.01 to 10 wt% based on 100 wt% . ≪ / RTI > As the hardening retarder, generally well known substances can be used, for example, 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.

In the present invention, a pigment used for realizing hue and improving the appearance can be further added, and it is preferable that the pigment is contained in an amount of 0.01 to 10% by weight based on 100% by weight of the total amount of the cement mortar composition for emergency repair. The pigment is added for easy identification, is easier to identify with a sharper color, and color persistence can be improved. The pigment may be at least one material selected from red iron oxide, yellow iron oxide, chromium oxide (CrO ₃ ), purple iron oxide and black iron oxide (carbon black), whereby red, green, yellow, , And white.

The cement mortar composition for emergency repair according to a preferred embodiment of the present invention may be prepared by mixing a quick hardening modified binder, a fine aggregate, and water, wherein the quick hardening modified binder contains a total of 100% by weight of the cement mortar composition for emergency repair, By weight, the fine aggregate is contained in an amount of 15 to 85% by weight, and the water is contained in an amount of 5 to 30% by weight.

The method of repairing and reinforcing a concrete structure using the cement mortar composition for emergency repair according to the present invention comprises: chipping an impurity or deteriorated part of a concrete structure with a grinder, a planer, a shot blaster or the like; Cleaning the chipped portion with a hand water jet, a vacuum inhaler or the like; A primer or blooming treatment to improve adhesion of the concrete concrete and the emergency repair cement mortar composition, suppress penetration of foreign matter, and improve water resistance and water resistance; Placing the emergency cement mortar composition according to the present invention on the primer or the blooming treated upper part using a spraying equipment; Surface-finishing the surface with a trowel or a sponge before the applied composition is completely cured; Applying a protective coating to the top of the surface-finished part to improve resistance to salt, neutralization resistance, surface hardness, water resistance and water resistance; And curing.

The primer may be at least one selected from the group consisting of styrene-butadiene latex, polyacrylic ester, acryl, ethylvinyl acetate, and acryl-urethane.

The protective coating may be at least one selected from the group consisting of water-based silica sol ceramic, acrylic-urethane, and silane penetration enhancer, but is not limited thereto.

Hereinafter, embodiments of the cement mortar composition for emergency repair according to the present invention will be more specifically shown and the present invention is not limited by the following embodiments.

(Example)

Example  One

30 kg of crude steel Portland cement, 20 kg of magnesium or calcium sulfoaluminate, 10 kg of alumina cement, 10 kg of meta kaolin, 10 kg of emery powder, 5 kg of gypsum, 5 kg of stellite, 2 kg of zinc chromate, 2 kg of aluminate strontium 0.5 kg of ethylene-vinyl acetate-acrylate copolymer, 0.5 kg of styrene-butyl acrylate copolymer, 0.5 kg of fluorine silane, 0.5 kg of bakelite, 0.5 kg of a mixture of hydro-bentonite methyl cellulose, 0.5 kg of polypropylene glycol, 0.5 kg of nylon fiber 0.5 kg of a high-performance water reducing agent, 0.5 kg of dimethyl silicone oil as a defoaming agent, 0.5 kg of citric acid as a curing retarder and 1 kg of red iron oxide as a pigment were mixed to obtain 100 kg of a quick hardening modified binder.

The high performance water reducing agent used herein was a mixture of a polycarboxylic acid based water reducing agent and a melamine sulfonic acid based water reducing agent in a weight ratio of 1: 0.2.

45 kg of the quick-hardening modified binder obtained above and 45 kg of fine aggregate were charged into a forced mixer and stirred. Then, 10 kg of water was further mixed and then stirred for 2 minutes to prepare 100 kg of the cement mortar composition for emergency repair according to the present invention Respectively.

Example  2

20 kg of magnesium or calcium sulfoaluminate, 10 kg of alumina cement, 10 kg of meta-kaolin, 10 kg of emery powder, 5 kg of gypsum, 3 kg of stellite, 2 kg of zinkchromate, 2 kg of strontium aluminate 1.5 kg of ethylene-vinyl acetate-acrylate copolymer, 1.5 kg of styrene-butyl acrylate copolymer, 1.5 kg of fluorine silane, 1.5 kg of bakelite, 1 kg of a mixture of hydrobentonite methylcellulose, 1 kg of polypropylene glycol, 0.5 kg of nylon fiber 0.5 kg of a high-performance water reducing agent, 0.5 kg of dimethyl silicone oil as a defoaming agent, 0.5 kg of citric acid as a curing retarder and 1 kg of red iron oxide as a pigment were mixed to obtain 100 kg of a quick hardening modified binder.

The high performance water reducing agent used herein was a mixture of a polycarboxylic acid based water reducing agent and a melamine sulfonic acid based water reducing agent in a weight ratio of 1: 0.2.

45 kg of the quick-hardening modified binder obtained above and 45 kg of fine aggregate were charged into a forced mixer and stirred. Then, 10 kg of water was further mixed and then stirred for 2 minutes to prepare 100 kg of the cement mortar composition for emergency repair according to the present invention Respectively.

Example  3

Crude steel Portland cement 24 kg, magnesium or calcium sulfoaluminate 20 kg, alumina cement 10 kg, meta kaolin 10 kg, emery powder 10 kg, gypsum 5 kg, stellite 5 kg, zinc chlormate 1 kg, strontium aluminate 1 kg 2 kg of ethylene-vinyl acetate-acrylate copolymer, 2 kg of styrene-butyl acrylate copolymer, 2 kg of fluorine silane, 2 kg of bakelite, 1.5 kg of a mixture of hydrobentonite methylcellulose, 1.5 kg of polypropylene glycol, 0.5 kg of nylon fiber 0.5 kg of a high-performance water reducing agent, 0.5 kg of dimethyl silicone oil as a defoaming agent, 0.5 kg of citric acid as a curing retarder and 1 kg of red iron oxide as a pigment were mixed to obtain 100 kg of a quick hardening modified binder.

The high performance water reducing agent used herein was a mixture of a polycarboxylic acid based water reducing agent and a melamine sulfonic acid based water reducing agent in a weight ratio of 1: 0.2.

45 kg of the quick-hardening modified binder obtained above and 45 kg of fine aggregate were charged into a forced mixer and stirred. Then, 10 kg of water was further mixed and then stirred for 2 minutes to prepare 100 kg of the cement mortar composition for emergency repair according to the present invention Respectively.

In order to compare the physical properties of the cement mortar composition for emergency repair prepared according to Examples 1 to 3 of the present invention, a currently widely used cement mortar composition is shown as Comparative Example 1 for comparison.

Comparative Example  One

45 kg of Portland cement and 45 kg of fine aggregate were added to a forced mixer and stirred. Further 9.5 kg of water was further mixed and stirred for 2 minutes. 0.5 kg of a polycarboxylic acid-based high-performance water reducing agent was added to prepare a cement mortar composition.

≪ Test Example 1 > Preparation of test specimens

(Polymeric cement mortar for repairing concrete structures) according to the formulations presented in Examples 1 to 3 and Comparative Example 1 of the present invention, and the test specimens having dimensions of 40 X 40 X 160 mm (for bending and compressive strength testing, length 150 X 5 mm for moisture permeation resistance test, 100 X 50 mm for chloride ion penetration resistance test, 100 X 100 X 100 mm for neutralization resistance, 150 X 40 mm for permeability test and water absorption coefficient test, The test specimens were prepared on a 70 x 70 x 20 mm cement mortar board with 40 x 40 x 10 mm (for bonding strength test) molds. Cements were cured in accordance with the site conditions.

≪ Test Example 2 >

In order to compare the strength characteristics of the composition prepared according to Examples 1 to 3 of the present invention with the composition prepared according to Comparative Example 1, the specimens prepared in Test Example 1 were compressed by KS F 4042 And bending strength and bond strength test were carried out. The results are shown in Tables 1 and 2 below.

division Strength (N / mm ² ) compression warp 4 hours 1 day 7 days 28th 4 hours 1 day 7 days 28th Example 1 30.0 38.2 50.2 52.0 6.3 9.0 10.5 11.8 Example 2 31.0 40.3 51.8 56.0 6.8 9.5 11.2 13.0 Example 3 32.5 41.9 53.0 59.0 7.5 9.8 12.1 14.0 Comparative Example 1 - 31.0 40.1 48.0 - 4.0 5.4 6.8

As shown in Table 1, the compositions prepared according to Examples 1 to 3 of the present invention were found to have superior bending strength and compressive strength as compared with the composition prepared according to Comparative Example 1.

division Bond strength (N / mm ² ) Standard condition After warm-cold repeat 4 hours 1 day 7 days 28th 4 hours 1 day 7 days 28th Example 1 1.7 1.82 2.1 2.25 1.45 1.63 1.85 2.05 Example 2 1.7 1.95 2.2 2.42 1.55 1.75 1.95 2.16 Example 3 1.8 1.95 2.22 2.52 1.6 1.82 2.05 2.24 Comparative Example 1 - - 1.4 1.85 - - 1.01 1.22

As shown in Table 2, the compositions prepared according to Examples 1 to 3 of the present invention were found to have excellent adhesion strength as compared with the compositions prepared according to Comparative Example 1.

≪ Test Example 3 > (Various properties test)

The alkaline resistance, neutralization resistance, permeability, water absorption coefficient, moisture permeation resistance, chloride ion penetration resistance, and rate of change of length of the composition prepared according to Examples 1 to 3 of the present invention and the composition prepared according to Comparative Example 1 were tested The results are shown in Table 3 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Alkali resistance (N / mm ² ) 48.0 52.3 54.3 33.0 Neutralization resistance (mm) 0.75 0.46 0.42 1.6 Permeability (g) 2.0 1.5 1.3 10.1 Water absorption coefficient (kg / m ² h ^0.5 ) 0.17 0.14 0.10 0.40 Moisture permeation resistance (Sd, m) 1.1 0.9 0.9 1.7 Chloride ion penetration resistance (Coulombs) 530 462 430 1,280 Length change rate (%) 0.01 0.008 0.004 0.06

As shown in Table 3, the compositions prepared according to Examples 1 to 3 exhibited excellent performance as compared with the compositions prepared according to Comparative Example 1. [

≪ Test Example 4 >

The composition prepared according to Examples 1 to 3 of the present invention and the cement mortar composition prepared according to Comparative Example 1 were subjected to a freeze-thaw resistance test according to the method defined in KS F 2456. Freezing and thawing means that the water absorbed in the concrete is frozen and melted. When freezing and thawing is repeated, fine cracks are generated in the concrete structure and the durability is lowered.

Table 4 shows the durability indexes of the compositions of Examples 1 to 3 and the composition of Comparative Example 1 according to the freeze-thaw resistance test.

division Example 1 Example 2 Example 3 Comparative Example 1 Durability index 92 93 93 69

As shown in Table 4 above, it can be seen that the compositions of Examples 1 to 3 are much higher in durability index than the composition of Comparative Example 1, so that the resistance to freezing and thawing is improved.

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, Modification is possible.

Claims (7)

delete delete delete delete delete Chipping the impurity or deteriorated portion of the concrete structure with a grinder, a planer, or a shot blaster;
Cleaning the chipped portion with a hand water jet, a vacuum inhaler or the like;
A method of repairing and reinforcing a concrete structure, comprising the steps of: applying a primer or blooming to improve the adhesion of the concrete concrete and the emergency repair cement mortar composition, suppress foreign matter penetration, and improve water resistance and waterproofing,
The primer or blooming treated cement mortar composition for emergency repair comprising 10 to 80 wt% of a quick hardening modified binder, 15 to 85 wt% of a fine aggregate, and 5 to 30 wt%
Wherein the quick hardening modified filler is, based on the total 100 weight% of the quick hard modified filler,
From 2 to 20% by weight of emerald powder, from 2 to 15% by weight of gypsum, from 15 to 84% by weight of crude steel Portland cement, from 2 to 40% by weight of magnesium or calcium sulfoaluminate, from 2 to 20% by weight of alumina cement, 1 to 15 wt% of stellite, 1 to 15 wt% of zinc chromate, 1 to 15 wt% of strontium aluminate, 0.5 to 10 wt% of ethylene-vinyl acetate-acrylate copolymer, styrene-butyl acrylate copolymer 0.5 From 0.5 to 10% by weight of fluorine silane, from 0.5 to 10% by weight of bakelite, from 0.5 to 10% by weight of hydrobentonized methylcellulose or polypropylene glycol, of polypropylene fiber, polyester fiber, nylon fiber, 10 to 10% by weight of a mixture of a polycarboxylic acid-based water reducing agent and a melamine sulfonic acid-based water reducing agent in a weight ratio of 1: 0.01 to 0.8, wherein the fine aggregate comprises: 0.45: 0.55, the method comprising: an emergency repair cement mortar composition for incorporation 0.9 laid using ppumchil equipment;
Surface-finishing the surface with a trowel or a sponge before the applied composition is completely cured; And
At least one kind of material selected from aqueous silica sol ceramic, acrylic-urethane and silane penetration enhancer is applied as a protective coating agent in order to improve the flame resistance, neutralization resistance and durability of the upper part of the surface finished part
Curing step,
The emergency repair cement mortar composition is formed into a single package type of powder,
The alkali 48.0 ~ 54.3N / mm ^2, water permeability is 1.3 ~ 2.0g, and the water absorption coefficient of ^{0.10 ~ 0.17kg / m 2 h 0.5} , a moisture permeation resistance 0.9 ~ 1.1m, the length rate of change of 0.004 ~ 0.01% A method of repairing and reinforcing a concrete structure. delete