KR101923493B1 - Mortar Composition with air-entraining agent for Concrete Repair and Concrete Repair Method Using the same - Google Patents

Abstract

The present invention relates to a mortar composition for repairing a cross section of concrete using an air entraining agent, and to a method for repairing and reinforcing a cross section of concrete using the same. By using an air entraining agent, workability can be enhanced by ball bearing effect of bubbles, adsorption to cement can be prevented, and desired initial air amount can be obtained in unhardened repair mortar. In addition, the plaster finishability and the construction quality can be enhanced by reducing the loss of the air amount after aging.

Description

Technical Field [0001] The present invention relates to a mortar composition for repairing a concrete using an air entraining agent and a method for repairing and reinforcing a concrete section using the same,

The present invention relates to a mortar composition for repairing a concrete section using an air entraining agent and a method for repairing and reinforcing the concrete section using the same. More particularly, the present invention relates to a mortar composition for repairing a section of a concrete using an air entraining agent The present invention relates to a method for repairing and reinforcing a section of a concrete using the same.

In general, the causes of cracks in concrete structures are largely due to structural cracks and unstructured cracks. Structural cracks are mostly caused by design errors or unexpected overloads. Unstructured cracks are caused by aggregate separation of concrete, drying shrinkage, Freezing and thawing, fire, corrosion of reinforcing steel, salting and alkali aggregate reaction cause cracks.

The size and shape of cracks in concrete vary depending on the nutrient factors and most of the cracks become wider over time and promote deterioration by inducing tearing and peeling of the cross section of the concrete.

Reinforced concrete structures are the most widely used structural methods in building construction. They have economical and stable structural performance. However, in the long run, they are in need of maintenance and management due to deterioration due to deterioration.

The maintenance method of the section of the concrete structure is to remove the deterioration part caused by material deterioration cause, design deterioration cause, deterioration cause contained in construction, external environment, etc., We perform construction.

The method of constructing the section maintenance mortar is to repair the concrete by removing the deteriorated by diffusing or penetrating the weakly acidic carbon dioxide gas into the concrete to neutralize the concrete and to reduce the air shortening of the section maintenance mortar, , And construction using a spraying machine to improve the finish of the plaster.

However, the conventional mortar for repairing a section has a problem that hose clogging and nozzle clogging occur during the construction using a spraying machine, so that a large amount of material is lost, and economic loss and extension of air due to replacement and repair due to mechanical damage occur.

Korean Patent Registration No. 0749926 'Resistance Mortar and Auto Leveling Materials Using Oyster Shells' (Registered on August 14, 2007)

The present invention provides a mortar composition for repairing a section of a concrete using an air entraining agent for improving the workability by ball bearing effect of air bubbles using an air entraining agent, and a method for repairing and reinforcing a section of a concrete using the same .

Another object to be solved by the present invention is to provide a mortar composition for maintenance of concrete using air entraining agent which prevents adsorption to cement and obtain desired initial air amount in unhardened maintenance mortar, And to provide a construction method.

Another object of the present invention is to provide a mortar composition for repairing a section of concrete using an air entrainment agent having an improved seismic resistance and a seismic resistant structure, and to provide a method for repairing and reinforcing a concrete section using the mortar composition.

In order to solve the above problems, the mortar composition for repairing a section of a concrete using the air entraining agent according to the present invention comprises 27 to 32% by weight of a cement mixture, 1 to 3% by weight of gypsum, 1.7 to 4.9% by weight of a pozzolanic substance, 3% by weight, inorganic expanding material 1.2 to 2.5% by weight, air entraining agent 0.004 to 0.01% by weight, retardant 0.006 to 0.02% by weight, water reducing agent 0.12 to 0.22% by weight, thickener 0.02 to 0.05% by weight, hydrophilic PVA fiber 0.05 to 0.3 %, Silica sand 54 to 68% by weight.

A method of repairing and reinforcing a section of concrete according to the present invention includes: removing a deteriorated surface of a concrete structure; Removing chipping or high pressure water and removing dust; Applying an impermeable primer to the surface of the concrete structure; Wherein the cement admixture comprises 27 to 32% by weight of cementitious mixture, 1 to 3% by weight of gypsum, 1.7 to 4.9% by weight of pozzolanic substance, 0.9 to 3% by weight of powder polymer, 1.2 to 2.5% by weight of inorganic expanding agent, 0.004 to 0.01% The mortar composition comprising 0.006 to 0.02% by weight of water reducing agent, 0.12 to 0.22% by weight of water reducing agent, 0.02 to 0.05% by weight of thickener, 0.05 to 0.3% by weight of hydrophilic PVA fiber and 54 to 68% by weight of silica sand is applied to the applied permeable primer layer step; Curing step; And applying an anti-pollution neutralization protecting agent.

In the present invention, before the step of applying the penetrating primer, the step of installing the seismic capacity reinforcing member fabricated by processing the basalt fiber may be provided on the surface of the concrete structure.

In the present invention, the gypsum may be composed of any one selected from anhydrous gypsum, alpha-hemihydrate, beta-hemihydrate, and diatomaceous earth, or a mixture thereof.

In the present invention, the pozzolanic material may be any one selected from fly ash, slag, silica fume, volcanic ash, tuff, or a mixture thereof.

In the present invention, the powder polymer may be composed of any one selected from EVA, SBR, ARCYL and PVAc, or a polymer compound thereof.

In the present invention, the air entraining agent may be a mixture of at least two of an anionic surfactant, a nonionic surfactant, and a positive ion surfactant.

In the present invention, the air entraining agent may be any one selected from the anionic surfactants or a mixture thereof in an amount of 50 to 70% by weight, any one selected from a positive ion surfactant and a nonionic surfactant or a mixture thereof 30 to 50% by weight.

In the present invention, the retarder has a function of inhibiting the formation of cement hydrate and freely adjusts the curing time and may be composed of any one selected from tartaric acid, gluconic acid, citric acid, oxycarboxylic acid compounds and saccharides or a mixture thereof.

In the present invention, the thickening agent may be any one selected from Starchia and Cellulose, or a mixture thereof.

The mortar composition for repairing an end face of a concrete using the air entraining agent according to the present invention may further comprise 0.2 to 0.8% by weight of the above-mentioned basalt fibers.

In the present invention, the alkaline mineral oil film having a carbon number of 20 to 40 is coated on the basalt fiber, and the length of the basalt fiber is 2 ~ 3 mm.

In the present invention, the gypsum further comprises 0.2 to 0.8% by weight of the basalt fiber, and the gypsum is composed of any one selected from anhydrous gypsum, alpha-hemihydrate, beta-hemihydrate and anhydrous gypsum, or a mixture thereof, The material is composed of any one selected from fly ash, slag, silica fume, volcanic ash, and tuff, or a mixture thereof, and the powder polymer is composed of any one selected from EVA, SBR, ARCYL and PVAc, The air entraining agent may be any one selected from the anionic surfactants or a mixture thereof in an amount of 50 to 70% by weight, any one selected from a positive ion surfactant and a nonionic surfactant, By weight, and the retardant has a function of inhibiting the formation of cement hydrate, so that the curing time can be freely controlled Wherein the thickener is composed of any one selected from the group consisting of stearic acid and cellulose, or a mixture thereof, wherein the thickening agent is selected from the group consisting of starch, gluconic acid, citric acid, oxycarboxylic acid compounds and saccharides, The fibers are coated with a mineral oil film and can be used differently depending on the construction site, with two lengths in the range of 3 to 9 mm.

The present invention has the effect of improving the walkability of the bubble due to the ball bearing effect by using the air entrainment agent.

The present invention prevents adsorption to cement, obtains a desired initial air volume in a hardened repair mortar, and reduces air loss after a lapse of time, thereby improving plaster finish and construction quality.

The present invention can improve the seismic performance of a concrete structure due to an earthquake, thereby minimizing damage to property and human life when an earthquake occurs.

1 is a flow chart for explaining a method of repairing and reinforcing a section of concrete according to the present invention.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

The mortar composition for repairing a section of a concrete using an air entraining agent according to the present invention comprises 27 to 32 wt% of a cementitious mixture, 1 to 3 wt% of a gypsum, 1.7 to 4.9 wt% of a pozzolanic substance, 0.9 to 3 wt% To about 2.5 wt.%, Air entraining agent 0.004 to 0.01 wt.%, Delaying agent 0.006 to 0.02 wt.%, Water reducing agent 0.12 to 0.22 wt.%, Thickener 0.02 to 0.05 wt.%, Hydrophilic PVA fiber 0.05 to 0.3 wt. %.

Also, the mortar composition for repairing an end face of a concrete using the air entraining agent according to the present invention may be composed of an earthquake-resistant mortar composition reinforced with an earthquake-proof performance further comprising 0.2 to 0.8% by weight of the basalt fiber.

The air entraining agent is exemplified by a combination of anionic, nonionic, and amphoteric surfactants.

More specifically, the air entraining agent may be any one of an anionic surfactant, a nonionic surfactant, and a positive ion surfactant, and may be at least one of an anionic surfactant, a nonionic surfactant, and a positive ion surfactant May be mixed and used.

Cement  mixture

And examples thereof include one selected from ordinary cement, medium-heat cement, crude steel cement, low-temperature cement, sulphate cement, low-speed mixed cement, and Irwin cement, or a mixture thereof.

If the cement content is less than 27 wt%, the required strength is not exhibited. If the cement content exceeds 32 wt%, the workability due to viscosity increase is reduced and cracks are generated due to high hydration heat, so that the blending ratio is preferably 27 to 32 wt% .

gypsum

And the gypsum is made of any one selected from anhydrous gypsum, alpha-type hemihydrate, beta-hemihydrated gypsum, and diatomaceous earth, or a mixture thereof.

If the amount of the gypsum is less than 1 wt%, the curing time of the cement mixture can not be shortened. If the amount of the gypsum is more than 3 wt%, the compressive strength is lowered.

Pozzolanic substance

The pozzolanic substance itself does not have a property of curing by reacting with water, but it reacts with calcium hydroxide in the state of fine powder under the condition of room temperature and in the presence of water to generate silicate or aluminate component having hydraulic property .

 The reaction of pozzolanic substances is called pozzolanic reaction. The effect of the pozzolanic material is incorporated into the cross-section repair mortar composition to chemically and physically fill the pores of the cemented body to densify it.

Examples of the pozzolanic material include any one selected from fly ash, slag, silica fume, volcanic ash, tuff, or a mixture thereof.

When the pozzolanic content is less than 1.7% by weight, the structure of the hydrated hardened body is not densified and the strength is lowered. When the amount of the pozzolanic substance is less than 4.9% by weight, unreacted materials are generated and physical properties are decreased. desirable.

powder Polymer

The powder polymer participates in the bonding surface between the hydrate of the cement and the silica sand so as to improve the adhesion of the maintenance mortar of the section, the crack inhibition effect, the corrosion resistance and the water resistance, and it is made of any one selected from EVA, SBR, ARCYL and PVAc, One example.

When the amount of the powder polymer is less than 0.9% by weight, the adhesive strength and the cracking inhibiting effect are insignificant. When the amount exceeds 3% by weight, the economical efficiency is lowered and the physical properties such as strength are lowered.

weapon Expander

The inorganic expanding material may be any one selected from the group consisting of K, S, and M, or a mixture thereof, but only compensating expansion for shrinkage.

In other words, in consideration of shrinkage which is a fatal disadvantage of cement, the use of an expanding agent suppresses the shrinkage of the cement so as not to overexpress or expand.

When the inorganic expanding material is less than 1.2% by weight, the expansion effect is insignificant and shrinkage cracking occurs. When the inorganic expanding material is more than 2.5% by weight, excessive expansion occurs and the cured product is destroyed and the physical properties are rapidly lowered. By weight is preferable

Air entrainment agent

The air entraining agent is a surfactant mainly focusing on the function of giving bubbles at the gas-liquid interface among the surfactants.

Air bubbles caused by the air entraining agent cause dispersion effect of cement paste, workability improvement by ball bearing effect, and reduction of material segregation effect.

Anionic surfactants are resin soaps, lactic acid esters and sulfides, and the active groups in the aqueous solution are cationic as they are charged with cations. The anion is active on the alkali side and the cationic surfactant on the acid side. An ether-based or ester-based nonionic system having a hydrophilic group such as a hydroxyl group or ethylene oxide as a hydrophilic group is used.

There is a problem that bubble formation is suppressed by the adsorption of the air entraining agent by the pozzolanic substance contained in the mortar composition for repairing the concrete using the air entraining agent, in particular, the unburnt carbon of the fly ash.

Accordingly, the air entraining agent is a combination of anionic, amphoteric and nonionic surfactant to prevent the generation of air bubbles by the unburned carbon of the fly ash and to enable the air bubbles to be generated smoothly.

That is, the air entraining agent is a mixture of at least two of an anionic surfactant, a nonionic surfactant, and a positive ion surfactant.

More specifically, the air entraining agent comprises 50 to 70% by weight of any one selected from the group consisting of anionic surfactants, a mixture thereof, a mixture selected from any one of a nonionic surface active agent and a nonionic surface active agent, or a mixture thereof To 50% by weight.

When the amount of the air entraining agent is less than 0.004% by weight, the dispersion effect and the workability are reduced. When the amount of the air entraining agent is more than 0.01% by weight, the strength is decreased remarkably due to excessive bubble entrainment, so that the blending ratio is preferably 0.004 to 0.01%

Retarder

The retarder has a function of inhibiting the formation of cement hydrate and freely adjusts the curing time and is exemplified by any one selected from the group consisting of tartaric acid, gluconic acid, citric acid, oxycarboxylic acid compounds and saccharides, or a mixture thereof.

If the retarding agent is less than 0.006 wt%, it is difficult to control the curing time when the temperature of the coating is increased. Surface cracking due to surface drying occurs on the surface of the coating. If the retarding agent is more than 0.02 wt%, the workability is improved, It is preferable to set the compounding ratio to 0.006 to 0.02% by weight because the physical properties such as the bending strength bond strength are lowered.

Water reducing agent

The water reducing agent causes an increase in the viscosity due to the specific surface area in the cementitious composition to use excessive mixing water, which causes a decrease in strength and a delay in curing.

 In order to solve this problem, a water reducing agent such as a naphthalene type, a melamine type, a polycarboxylic type or the like or a fluidizing agent which can be effectively used only by a small amount can be used, or a mixture thereof.

When the amount of the water reducing agent is less than 0.12% by weight, the compressive strength and the bending strength decrease with an increase in the use of mixed water. When the water reducing agent is used in an amount exceeding 0.22% by weight, the material is separated and flows down during the ceiling and wall construction due to the improved flowability. The blending ratio is preferably 0.12 to 0.22% by weight.

Thickener

The thickener is composed of any one selected from Starchia and Cellulose, or a mixture thereof. In order to prevent the deterioration of the bondability between cement and silica due to the rapid drying of the water due to the high temperature due to the high temperature during the summer season It is used to increase the adhesion with the repair surface.

When the amount of the thickener is less than 0.02% by weight, the adherence due to the decrease in viscosity decreases. When the amount of the thickener is more than 0.05% by weight, mechanical properties and plaster finishability are lowered due to excessive viscosity increase, 0.05% by weight.

Hydrophilic PVA fiber

Hydrophilic PVA fiber has the brittleness which causes sudden fracture under the tensile and dynamic load which is a disadvantage of repair mortar and it is hard to suppress the generation and growth of crack by the mechanical resistance such as increase in tensile resistance ability, It is reinforcing fiber for making fiber reinforced mortar by dispersing discontinuous single phase fiber material in repair mortar to improve and reinforce property.

Hydrophilic PVA microfibers are very resistant to carbon-containing solvents, oils, salts and alkalis and have excellent resistance to exposure to direct sunlight.

The hydrophilic PVA microfibers are hydrophilic structures having hydroxyl groups on the fiber surface and are dispersed well and have high adhesion ability and have relatively small diameters to suppress and stabilize microcracks and increase mechanical properties through crosslinking of fibers It is very effective, effective in suppressing cracks caused by fatigue and impact load, and has excellent finish due to no surface exposure.

The hydrophilic PVA microfibers have a length of 3 to 8 mm. When the hydrophilic PVA microfibers are less than 0.05% by weight, the effect of suppressing cracks caused by fatigue and impact load is reduced, and when 0.3% , A fiber ball is generated to cause a sudden decrease in physical properties. Therefore, it is preferable that the blending ratio is 0.05 to 0.3% by weight of the hydrophilic PVA fiber.

Silica sand

The silica sand has strong abrasion resistance and impurities, and the moisture content influences the mixing with the repair mortar composition. Therefore, it is possible to use dried silica sand having a good size and shape.

The size of the silica sand is used from 0.05 mm to 3 mm according to the construction thickness and the shape of the silica sand is rough to maximize the adhesion area between the silica sand and the cement paste. When the silica sand is less than 54% by weight, Cracks may be generated due to the generation of high hydration heat. When the content exceeds 68% by weight, the durability is lowered due to the decrease in the relative amount of cement, so that the blending ratio is preferably 54 to 68% by weight in consideration of the specific gravity of silica sand

Basalt fibers

Basalt fiber is a non-toxic inorganic rock fiber made of natural basalt fiber, which is less expensive than other inorganic fibers (glass fiber, metal fiber, aramid fiber, etc.) and has electrical insulation, dustproofness, heat resistance, It has the advantages of swelling, soundproofing, sound absorption, erosion resistance, corrosion resistance, abrasion resistance, chemical stability, self-lubricating property, light weight and high strength characteristics and can be easily broken due to strong fire and tensile strength. In addition, the above-mentioned basalt fiber is advantageous in that it has better properties than conventional glass fibers and is eco-friendly. In this case, the bar-cut fiber preferably contains 47.5 to 55.0 wt% of SiO ₂ , 0.2 to 2 wt% of TiO ₂ , 14 to 20 wt% of Al ₂ O ₃ , 7 to 13.5 wt% of a mixture of Fe ₂ O ₃ and FeO, It is preferable that it comprises 7 to 11 wt% of CaO, 3 to 8.5 wt% of MgO, 0.25 wt% of MnO, 2.5 to 7.5 wt% of a mixture of Na ₂ O and K ₂ O, and 0.2 to 0.8 wt% of SO ₃ . It is preferable that the above-described basalt fibers are used in an amount of 0.2 to 0.8% by weight based on the whole mortar composition according to the present invention. If the content of the above-mentioned basalt fibers is less than 0.2% by weight, heat resistance, cracking, , And if it exceeds 0.8% by weight, it is not uniformly mixed in the mortar composition due to excessive aggregation. In particular, in order to solve the problem that even when mixed with 0.8% by weight of the basalt fiber used in the mortar composition according to the present invention, the fibers may not be uniformly mixed at the time of production in a mortar factory due to aggregation and poor workability, To be dispersed in mineral oil so as to increase the dispersibility, and then forming a coating film so that the mutual material forms an air layer. The mineral oil is also referred to as liquid paraffin. The mineral oil used in the present invention is preferably an alkane mineral oil having 20 to 40 carbon atoms. When the basalt (volcanic rock) is melted at 1,500 캜 and spun into a filament having a diameter of 9 to 20 탆 by centrifugal force, the coated bazaart fiber is sprayed with a low viscosity mineral oil and then coated in a range of 3 to 9 mm It is preferable to cut them so as to have two different lengths and to be used differently depending on the construction site.

Meanwhile, the method for repairing and reinforcing a section of concrete according to the present invention comprises the steps of removing a deteriorated surface of a concrete structure (S300), removing chipping or high pressure water and removing dust (S310), penetrating the surface of a concrete structure (3) a step of applying a primer to the cementitious mixture, wherein the cementitious mixture comprises 27 to 32 wt%, gypsum of 1 to 3 wt%, pozzolanic material of 1.7 to 4.9 wt%, powder polymer of 0.9 to 3 wt%, inorganic expanding material of 1.2 to 2.5 wt% The present invention comprises 0.004 to 0.01% by weight of an initiator, 0.006 to 0.02% by weight of a retarder, 0.12 to 0.22% by weight of a water reducing agent, 0.02 to 0.05% by weight of a thickener, 0.05 to 0.3% by weight of hydrophilic PVA fibers, (S340), curing (S350), and applying a contamination neutralization protecting agent (S360) to the permeable primer layer applied to the mortar composition according to the present invention.

At this time, in the step S340, the mortar composition applied on the permeable primer layer further comprises 0.2 to 0.8 wt% of the zeolite fiber, and the zeolite fiber is an alkane mineral oil film having a carbon number of 20 to 40 And it is preferable to use two kinds of lengths in the range of 3 to 9 mm depending on the construction site.

In addition, the method for repairing and reinforcing a section of concrete according to the present invention is characterized in that, prior to the step of applying the penetrating primer, the method for repairing and reinforcing the section of a concrete is provided with a seismic capacity reinforcing member (a rib member, Sheet member, etc.) on the surface of the concrete structure (S320).

That is, after the step of removing chipping or high-pressure water and removing dust (S310), the earthquake-proof strength reinforcing material produced by processing the basalt fiber before the step S330 of applying the permeable primer is applied to the surface of the concrete structure And the permeable primer is applied to the surface of the concrete structure where the earthquake-proof reinforcement is installed.

The surface treatment (S300) of the surface (work surface) of the concrete structure is a step of sorting out the surface of the aged or deteriorated or deteriorated concrete structure by using a grinder, a breaker or the like.

In the step of removing high pressure water and removing dust (S310), a cleaning step is performed to remove foreign matter, dust, dust, etc. on the surface of the surface-treated concrete structure by water sprayed from the high-pressure cleaner or air injected from the air compressor. In the case of removing foreign matter or residue on the surface of a concrete structure with a high-pressure washer, it is desirable to remove the remaining water. In step S310, when damages such as falling off occur on the surface of the concrete structure, the surface treatment can be performed by charging the earthquake-resistant mortar composition according to the present invention.

Step S320 of installing the earthquake-proof strength stiffener to the concrete structure is to install the earthquake-proof strength stiffener including the earthquake-proof strength stiffener produced by processing the basalt fiber, that is, the basalt fiber, in the concrete structure.

The step S330 of applying the penetrating primer is a step of applying a penetrating primer layer for strengthening the aged concrete structure before the earthquake-resistant mortar composition is applied. For example, a strengthening agent such as a permeable concrete protective primer may be applied , Roller, spray or the like so as to be sufficiently infiltrated.

In the step of constructing the earthquake-resistant mortar composition (S340), the earthquake-resistant mortar composition according to the present invention is mixed with water, and then the mortar layer is applied by applying plaster, shotcrete or injection method. The cladding of the mortar layer has a thickness such that the earthquake-proof strength stiffener is completely immersed depending on the thickness of the constructed earthquake-proof strength stiffener.

Thereafter, after a curing step (S350) of wet curing for about three days or more, a step S360 of applying an anti-pollution neutralization protecting agent for applying the contamination neutralization protecting agent is performed. It is preferable to use a neutralization protecting agent having a thickness of 2 mm or less and applying thinly one to two times with a brush, roller, spray or the like, and also to prevent contamination with fluorescence, color and transparency.

In the present invention, the basalt fiber contained in the mortar composition applied on the permeable primer layer is prepared by melting a specific oropharyngeal mixture of pulverized basalt rocks at a temperature between 1250 ° C and 1,500 ° C, stirring the mixture, and melt- Filament yarn.

Basalt fiber, ie, basalt fiber, is a natural mineral material made by melting basalt. It has low density, mechanical properties with excellent elastic modulus and strength, high resistance to corrosion and physical damage at high temperatures up to 1200 ℃ It is also excellent in heat resistance and does not occur. In addition, it is an eco-friendly material such that production processability is simple and cost of production is low, economical efficiency is better than that of carbon fiber, and exhaust gas and waste are not generated during production. Table 1 compares the mechanical properties of the basalt fibers with those of carbon fibers and glass fibers.

characteristic Basalt fibers E-Glass S-Glass Carbon fiber Tensile Strength (MPa) 3,000 ~ 4,840 3,100 ~ 3,800 4,020 ~ 4,650 3,500 ~ 6,000 The modulus of elasticity (Gpa) 79.3 to 93.1 72.5 to 75.5 83 ~ 86 230 ~ 600 Elongation (%) 3.1 4.7 5.3 1.5 to 2.0 Diaphragm diameter (㎛) 6 ~ 21 6 ~ 21 6 ~ 21 5 to 15 Linear density (tex) 60 ~ 4,200 40 to 4,200 40 to 4,200 60 to 2,400 Operating temperature (℃) -260 to + 800 -50 to + 300 -50 to + 300 -50 to + 700

Among the reinforcements for earthquake-proof strength, the ribbed fabric made from the basalt fiber is formed by forming a strand, which is made of basalt fiber (basalt fiber), on the epoxy-based resin to form a hardened core and passing through a drawing die The outer circumferential surface of one core material is made by winding a strand of basalt fiber onto a resin and winding it along a spiral path with a cured filament and heating and curing. Such a rebar processed with the basalt fiber is used as reinforcing material or substitute for reinforcing steel because it has a higher tensile strength and compressive strength than ordinary steel and is not corroded and has less weight and is excellent in workability and is environmentally friendly and inexpensive. It is used as the material of the reinforcement method. At this time, it is preferable that the core and the spiral filament are coated with a covering layer surrounding the core and the spiral filaments, which include a plurality of particles (for example, silica sand) adhered and fixed to the resin included in the core and the spiral filaments. The surface area in contact with the earthquake-resistant mortar composition according to the present invention is larger than that of the FRP rebar having a smooth outer circumferential surface. In addition, since particles such as silica sand are also used as materials for the earthquake-resistant mortar composition according to the present invention, the degree of heterogeneity between the outer layer and the mortar is also reduced. Therefore, when the rebar processed with the basalt fiber is disposed inside the mortar, the adhesion of the rebar processed with the mortar and the basalt fiber is greatly improved, so that the rebar processed with the basalt fiber can not be separated from the mortar even after a long time after the mortar curing, Adhesion and flexural strength and durability with concrete structures are improved. Particularly, in the present invention, it is preferable to use the RockRebar product of Raw Energy Materials as one example commercialized as a rebar processed with the above-mentioned basalt fiber. A more specific structure of the ribbed fabric used in the present invention is a Korean patent application filed by the same applicant of the present invention as a Korean patent application No. 10-2018-0009351 which is a basis of the priority claim of the present invention An environmentally friendly earthquake-resistant mortar composition and a method for producing the same) have been disclosed.

The rebar fabricated with the bar-ath fibers has a weight of 1/4 and a tensile strength of 2.2 times higher than that of the grade 60 steel reinforcement and does not cause corrosion problems.

Rivas fabricated with basalt fibers can be ribbed in the form of protrusions of various sizes (diameter: Ψ3 to Ψ15) made of basalt fibers.

Rivals made of basalt fiber are naturally resistant to corrosion, rust, alkaline and acid. They prevent rusting of concrete caused by water penetration because they do not rust and do not require special coatings to withstand high Ph.

In addition, the rebar processed with the basalt fiber does not absorb and transmit moisture like glass fiber, so that the corrosion does not proceed even when the fiber is exposed. Therefore, the performance of the concrete structure is not deteriorated, It is possible to prevent decomposition.

Meanwhile, Table 2 shows the composition and the content ratio of the mortar composition for repairing the concrete using the air entraining agent according to the present invention and the comparative example of the present invention.

Example Comparative Example 1 Comparative Example 2 Cement mixture 30 30 30 gypsum 2 2 2 Pozzolanic substance 3 One 3 Powder polymer 1.6 1.6 1.6 Inorganic expander 2 2 2 Air entrainment agent 0.007 0.004 0.02 Retarder 0.013 0.013 0.013 Water reducing agent 0.15 0.15 0.15 Thickener 0.03 0.03 0.03 PVA fiber 0.2 0.2 0.2 Silica sand 61 63 61 Sectional maintenance mortar total 100 100 100 water 16 16 16

As shown in Table 2 above, Example 1 of the present invention is a mortar composition corresponding to the composition ratio of a mortar composition for repairing concrete using an air entraining agent according to the present invention.

Comparative Example 1 corresponds to the composition ratio of the mortar composition for repairing the concrete using the air entraining agent according to the present invention at the air entraining agent of 0.004% by weight. However, in the case of the concrete end surface repair using the air entraining agent according to the present invention, Is a mortar composition which does not correspond to the composition ratio of the mortar composition.

In addition, Comparative Example 2 is a mortar composition which does not correspond to the composition ratio of the mortar composition for repairing concrete using the air entraining agent according to the present invention, wherein the air entraining agent is 0.02 wt%.

Test Items standard Example 1 Comparative Example 1 Comparative Example 2 Compressive strength (N / mm ² ) 20.0 or higher 41.5 32.1 24.3 Bond strength (N / mm ² ) 1.0 or higher 1.9 1.2 0.9 Bending strength (N / mm ² ) 6.0 or higher 11.3 5.3 4.5 Length change rate (%) ± 0.15 +0.01 -0.12 -0.2 Neutralization resistance (mm) 2.0 or less 0.5 2.4 4.5 Air volume (%) 3 to 5 4.5 3.9 8

As can be seen from Table 3, Example 1 satisfying the composition ratio of the mortar composition for repairing concrete using the air entraining agent according to the present invention satisfies the criteria of the test items.

However, in the Comparative Example 1 in which the composition ratio of the mortar composition of the concrete using the air entraining agent according to the present invention was satisfied but the amount of the pozzolanic substance was reduced in order to approximate the air amount to the target value, the flexural strength and the neutralization resistance Respectively.

Also, in Comparative Example 2 in which the air entraining agent was excessively mixed, it was confirmed that all properties except the compressive strength were below the reference value.

Table 4 below shows the compounding ratio of the air entraining agent mixture in Examples 2 to 5 and Comparative Example 3 of the present invention in which the compounding ratio of the air entraining agent mixture in Example 1 of Table 2 was varied.

That is, Comparative Example 3 is an example in which the air entraining agent is mixed only with an anionic surfactant in the mortar composition of Example 1, while Examples 2 to 5 are examples of an anionic surfactant, a nonionic surfactant, a positive ion surfactant Are mixed and used.

Comparative Example 3 Example 2 Example 3 Example 4 Example 5 Anion system 100 wt% 70 wt% 70 wt% 50 wt% 50 wt% Nonionic system - 30 wt% - 50 wt% - Amphoteric system - - 30 wt% - 50 wt%

In Table 4, Example 2 is an air entraining agent mixture in which 70% by weight of an anionic surfactant and 30% by weight of a nonionic surfactant are mixed. In Example 3, 70% by weight of an anionic surfactant and 30% Example 4 is an air entraining agent mixture in which 50% by weight of an anionic surfactant and 50% by weight of a nonionic surfactant are mixed. In Example 5, 50% by weight of an anionic surfactant and 50% By weight of an air entraining agent.

Table 5 below shows the mortar compositions of Examples 2 to 5 and Comparative Example 3 in order to confirm whether or not the air bubbles contributed to the improvement in walkability by the ball bearing effect in the air entraining agent mixture shown in Table 4, And the change of FLOW over time is measured several times and the test result of the plaster finish is measured.

Comparative Example Example 2 Example 3 Example 4 Example 5
Air volume (%) I'm 4.5 4.5 4.6 4.3 4.5 after 2.9 4.2 4.2 3.9 4.1 Rate of change 35.5% ↓ 6.7% ↓ 8.7% ↓ 9.3% ↓ 8.9% ↓
FLOW I'm 16.5 16.5 16.7 16.3 16.6 after 13.5 16.1 16.2 15.9 16.2 Rate of change 18.2% ↓ 2.4% ↓ 3.0% ↓ 2.6% ↓ 2.4% ↓ Plaster finish Bad Good Good Good Good

In Table 5, in Comparative Example 3, an anionic surfactant alone was used, and air bubbles were adsorbed on cement and adsorbed on the unburned carbon of fly ash, and the air amount and FLOW were wide before and after the machine hose to be sprayed. It was confirmed that after the construction, the finish of the plaster was inferior.

On the other hand, Examples 2 to 5 are examples using anionic, nonionic, and amphoteric complexes. When at least two of anionic, nonionic, and amphoteric ionic materials are mixed, It is possible to obtain a desired initial air amount in the unhardened maintenance mortar, and to reduce the loss of the air amount after a lapse of time.

Therefore, in Examples 2 to 5, it was satisfied that the air quality was maintained within 10% of the target change management, and the satisfaction with the FLOW over time target management value was satisfied to within 5%, which is related to the improvement of the plaster finish, .

The present invention can improve the workability by the ball bearing effect of bubbles by using an air entraining agent.

The present invention prevents adsorption to cement, obtains a desired initial air amount in a hardened repair mortar, and reduces loss of air amount after a lapse of time, thereby improving plaster finish and construction quality.

The present invention improves the seismic performance of a concrete structure that is resistant to an earthquake, thereby minimizing damage to property and human life when an earthquake occurs.

As described above, an optimal embodiment has been disclosed in the drawings and specification. While specific terms have been employed herein, they are used for the purpose of describing the invention only and are not used to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

S300: Surface treatment step S310: Cleaning and dust removal step
S320: Stiffener mounting step S330: Infiltrating primer coating step
S340: Seismic Mortar Composition Construction Step S350: Curing Step
S360: Application of the contamination neutralization protecting agent

Claims (22)

Wherein the cement admixture comprises 27 to 32% by weight of cementitious mixture, 1 to 3% by weight of gypsum, 1.7 to 4.9% by weight of pozzolanic substance, 0.9 to 3% by weight of powder polymer, 1.2 to 2.5% by weight of inorganic expanding agent, 0.004 to 0.01% Wherein the hydrophilic PVA fiber comprises from 0.006 to 0.02% by weight of water reducing agent, 0.12 to 0.22% by weight of water reducing agent, 0.02 to 0.05% by weight of thickener, 0.05 to 0.3% by weight of hydrophilic PVA fiber, 54 to 67%
Wherein the gypsum is composed of any one selected from anhydrous gypsum, alpha-hemihydrate, beta-hemihydrate and astaxanthrene, or a mixture thereof,
The pozzolanic material may be any one selected from fly ash, slag, silica fume, volcanic ash, and tuff, or a mixture thereof,
The powder polymer is composed of any one selected from EVA, SBR, ARCYL, and PVAc, or a polymer compound thereof,
The air entraining agent may be any one selected from the anionic surfactants or a mixture thereof in an amount of 50 to 70% by weight, any one selected from a positive ion surfactant and a nonionic surfactant, % By weight,
The retarder has a function of inhibiting the formation of cement hydrate and freely adjusts a curing time and is composed of any one selected from the group consisting of tartaric acid, gluconic acid, citric acid, oxycarboxylic acid compounds and saccharides, or a mixture thereof,
The thickening agent may be any one selected from the group consisting of a star system and a cellulose system, or a mixture thereof,
Wherein the basalt fiber is coated with an alkane mineral oil film having 20 to 40 carbon atoms and cut to have a length within a range of 3 to 9 mm. delete delete delete delete delete delete delete delete delete delete Removing the deteriorated surface of the concrete structure; Removing chipping or high pressure water and removing dust;
Applying an impermeable primer to the surface of the concrete structure;
Wherein the cement admixture comprises 27 to 32% by weight of cementitious mixture, 1 to 3% by weight of gypsum, 1.7 to 4.9% by weight of pozzolanic substance, 0.9 to 3% by weight of powder polymer, 1.2 to 2.5% by weight of inorganic expanding agent, 0.004 to 0.01% A mortar composition comprising 0.006 to 0.02 wt% of a water reducing agent, 0.12 to 0.22 wt% of a water reducing agent, 0.02 to 0.05 wt% of a thickening agent, 0.05 to 0.3 wt% of hydrophilic PVA fibers, 54 to 67 wt% of silica sand, and 0.2 to 0.8 wt% Applying to the applied permeable primer layer;
Curing step; And
And applying a contamination neutralization protecting agent,
Wherein the gypsum is composed of any one selected from anhydrous gypsum, alpha-hemihydrate, beta-hemihydrate and astaxanthrene, or a mixture thereof,
The pozzolanic material may be any one selected from fly ash, slag, silica fume, volcanic ash, and tuff, or a mixture thereof,
The powder polymer is composed of any one selected from EVA, SBR, ARCYL, and PVAc, or a polymer compound thereof,
The air entraining agent may be any one selected from the anionic surfactants or a mixture thereof in an amount of 50 to 70% by weight, any one selected from a positive ion surfactant and a nonionic surfactant, % By weight,
The retarder has a function of inhibiting the formation of cement hydrate and freely adjusts a curing time and is composed of any one selected from the group consisting of tartaric acid, gluconic acid, citric acid, oxycarboxylic acid compounds and saccharides, or a mixture thereof,
The thickening agent may be any one selected from the group consisting of a star system and a cellulose system, or a mixture thereof,
Wherein the basalt fiber is coated with an alkane mineral oil film having 20 to 40 carbon atoms and cut to have a length within a range of 3 to 9 mm. delete delete delete delete delete delete delete delete delete The method of claim 12,
Further comprising a step of installing an earthquake-resistant strength reinforcing material prepared by processing the basalt fiber on the surface of the concrete structure before the step of applying the penetrating primer.

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