KR20170116935A - Performance improving agent for concrete structure and repairing method of concrete structure using the same - Google Patents

Abstract

According to an embodiment of the present invention, there is provided a method of repairing a concrete structure, the method comprising: a pretreatment step of removing foreign matter from a damaged area in a repair method of a neutralized concrete structure; A first coating layer forming step of applying a performance improving material of a concrete structure to the damaged area to form a first coating layer to restore the alkalinity and strength of the concrete structure; A repair concrete pouring step of pouring the repair concrete on the damaged area coated with the first coating layer to form a repair layer on the damaged area; Forming a second coating layer by coating the performance improving material of the concrete structure on the surface of the conserved layer to prevent the neutralization of the conserved layer; And a finishing step of applying a paint selected from the group consisting of acrylic, epoxy, urethane-based urea and mixtures thereof to the surface of the second coating layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete structure repairing material and a concrete structure repairing method using the same.

The present invention relates to a performance improving material for a concrete structure and a method for repairing a concrete structure using the same. More particularly, the present invention relates to a method for repairing a damaged concrete structure, such as a crack generated while restoring the alkalinity of a neutralized concrete structure. And a method for repairing a concrete structure using the same.

In general, concrete is a semi-permanent material widely used in construction, civil engineering, etc., and the concrete structure constructed with such concrete occupies a large scale as a social property.

The durability of the concrete structure gradually deteriorates due to environmental factors as time goes by, and the performance of the concrete structure is deteriorated.

Especially, concrete neutralization is a typical performance deterioration mechanism. Concrete has strong alkalinity of about 12 ~ 13 pH immediately after casting, but gradually disappears due to exposure to carbon dioxide gas and acid rain, etc., such as carbon dioxide (CO ₂ ) Alkalinity is lost to about 10%.

In addition, cracks and other damages occur due to the progressive neutralization of the concrete, which not only damages the appearance of the concrete structure but also aggravates the deterioration of the concrete due to infiltration of carbon dioxide gas and acid rain through the cracks Lt; / RTI >

Recently, concrete neutralization is accelerating due to environmental factors such as increase in acid rain cost and automobile exhaust gas.

Therefore, a concrete repair material for repairing concrete structures by applying or filling cracks such as cracks in concrete has been developed.

However, the above-described concrete repair material simply fails to restore the alkalinity of the neutralized concrete and can not solve the problem that the durability of the concrete structure is deteriorated.

Korean Patent Registration No. 10-1013939 (Feb. 14, 2011)

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to improve the durability and life of a concrete structure by restoring the alkalinity of the neutralized concrete structure while repairing the concrete structure by filling in cracks or the like of the neutralized concrete structure And a method of repairing a concrete structure using the same.

According to an embodiment of the present invention, there is provided a method of repairing a concrete structure, the method comprising: a pretreatment step of removing foreign matter from a damaged area in a repair method of a neutralized concrete structure; A first coating layer forming step of applying a performance improving material of a concrete structure to the damaged area to form a first coating layer to restore the alkalinity and strength of the concrete structure; A repair concrete pouring step of pouring the repair concrete on the damaged area coated with the first coating layer to form a repair layer on the damaged area; Forming a second coating layer by coating the performance improving material of the concrete structure on the surface of the conserved layer to prevent the neutralization of the conserved layer; And a finishing step of applying a paint selected from the group consisting of acrylic, epoxy, urethane-based urea and mixtures thereof to the surface of the second coating layer.

Preferably, the method for repairing a concrete structure according to an embodiment of the present invention further comprises, after the step of forming the second coating layer, 40 to 50 wt% of acrylic polymer, 40 to 50 wt% of calcium carbonate, 3 to 5 wt% of titanium dioxide, Forming a third coating layer by applying an elastic repair material containing 0.1 to 0.5 wt% of a wetting agent, 0.1 to 3 wt% of a pH adjusting agent, 3 to 4 wt% of water and other unavoidable impurities to the second coating layer plane, ; ≪ / RTI >

The elastic repair material preferably further comprises 0.5 to 1 wt% of a fiber reinforcing material.

Also, before the pretreatment step, the performance of the concrete structure comprising 15 to 20 wt% of an alkaline restorer, 45 to 55 wt% of a binder, 1 to 5 wt% of silane, 1 to 5 wt% of IPA (icosapentaenoic acid) or phosphoric acid and 30 to 50 wt% And a preparation step of preparing an improvement material.

Wherein the preparation step comprises: preparing a binder aqueous solution by mixing the binder and water to prepare a binder aqueous solution; A heating process of heating the binder aqueous solution to 60 占 폚; A stirring step of adding an alkaline recovery agent to the heated aqueous binder solution and stirring the primary to prepare a maintenance agent mixture; A cooling process for cooling the maintenance material mixture to 60 캜; And a finishing step of adding the silane and IPA or phosphoric acid to the maintenance material mixture and then agitating the same to prepare the performance improving material for the concrete structure.

It is preferable that the binder contains at least one of lithium silicate, sodium silicate and potassium silicate, and the alkali remover is one selected from potassium hydroxide and sodium hydroxide.

The performance improving material for a concrete structure according to an embodiment of the present invention is a concrete structure performance improving material for repairing a damaged concrete structure by neutralization, which comprises 20 to 40 wt% of an alkali recovery agent, 15 to 20 wt% of a binder, 0.5 to 5 wt% IPA (icosapentaenoic acid) or 1 to 5 wt% phosphoric acid and 30 to 50 wt% water.

The alkali remover may be one selected from the group consisting of potassium hydroxide and sodium hydroxide, and has a pH of 12 to 14.

The binder is preferably one selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, and mixtures thereof.

According to the embodiment of the present invention, the alkalinity of a concrete structure degraded due to aging due to neutralization or the like is restored, thereby prolonging the life of the concrete structure and improving safety.

In addition, there is an effect of enhancing the strength of the concrete structure and improving the water resistance and the neutralization resistance by applying it to the surface of the concrete structure, filling or repairing the damaged portion such as cracks.

1 is a flowchart illustrating a method for repairing concrete structures according to an embodiment of the present invention,
FIG. 2 is a cross-sectional view illustrating cracks in a repaired concrete structure according to an embodiment of the present invention. Referring to FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments.

For reference, the same numbers in this description refer to substantially the same elements and can be described with reference to the contents described in the other drawings under these rules, and the contents which are judged to be obvious to the person skilled in the art or repeated can be omitted.

The method of repairing concrete structures according to an embodiment of the present invention is characterized by coating or filling the surface of a neutralized concrete or a damaged part to improve the water resistance of the concrete structure, restore the alkaline property, extend the service life and improve the stability.

FIG. 1 is a flowchart illustrating a concrete structure repairing method according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating cracks in a repaired concrete structure according to an embodiment of the present invention.

1 and 2, a method of repairing concrete structures according to an embodiment of the present invention includes a pretreatment step of removing foreign matter from a damaged portion of a concrete structure 10, a pretreatment step of removing foreign matter from a damaged portion of the concrete structure 10, 100, forming a repair layer 200 by filling the repair concrete within the damage site, forming a second coating layer 300 on the surface of the repair layer, And a finishing step of coating the surface of the second coating layer 300 to form a coating layer 500.

First, the pretreatment step is a step of removing foreign matter from a portion to be repaired. When the refuse is to be repaired due to deterioration due to aging or rebar corrosion due to progress of neutralization, the portion to be repaired is chipped and removed And remove foreign substances such as dust and laitance.

The first coating layer forming step may include coating the first coating layer 100 with the performance improving material of the concrete structure to the repair part from which foreign matters have been removed so as to improve the performance of the reinforcing bars inside the concrete structure 10, .

Preferably, the method of repairing concrete structures according to an embodiment of the present invention may further include a step of preparing a concrete structure performance improving material before the pre-treatment step.

The preparation step comprises mixing 15 to 20 wt% of an alkaline recovery agent, 45 to 55 wt% of a binder, 1 to 5 wt% of silane, 1 to 5 wt% of IPA (icosapentaenoic acid) or phosphoric acid and 30 to 50 wt% of water to prepare a concrete structure performance improving material .

According to an embodiment of the present invention, the alkaline recovery agent may be one selected from potassium hydroxide or sodium hydroxide, and the pH is 12 to 14. The binder may include at least one silicate such as lithium silicate, sodium silicate potassium silicate, .

This is because when the pH of the alkaline remover is less than 12, the alkaline recovery is insufficient and the performance recovery efficiency of the concrete structure 10 is lowered. When the pH is more than 14, it is difficult to handle, The reinforced concrete structure 10 can improve the rustproofing and waterproofing effect of the concrete structure 10 and improve the durability and the life of the concrete structure 10 by forming a coating film having a rust- It is because.

If the amount of the alkaline recovery agent is less than 15 wt%, the degree of alkaline recovery of the damaged portion is insignificant. If the amount of the alkaline recovery agent is more than 20 wt%, the adhesion strength may be lowered and the durability may deteriorate. If the content is less than 45 wt%, the effect is insufficient. If it exceeds 55 wt%, the adhesion strength may be lowered. If the content of silane is more than 1 wt%, the strength of the first and third coating layers may be improved However, when it exceeds 5 wt%, the strength is not further improved, so that the above range is limited.

On the other hand, since the silane has hydrophobicity, water is prevented from penetrating from the outside of the concrete structure 10, and moisture penetrates into the concrete structure 10 during the process of melting ice or snow accumulated on the surface of the concrete structure 10 in winter Corrosion and deterioration of the concrete structure 10 can be minimized by blocking the ultraviolet rays.

In this case, the silane according to an embodiment of the present invention has a refractive index of 1.3765, a viscosity of 6.5 to 7.0 mm 2 / s at 25 ° C, a flash point of 100 ° C, a nonvolatile content of less than 25 wt%, a neutralization equivalent Equivalent It is desirable to use it in the form of fine particles having the property of 346.

In addition to the above-mentioned effects, the binder has an adhesive force that the binder does not have, thereby improving the adhesive force.

Also, IPA (icosapentaenoic acid) or phosphoric acid is added to inhibit the corrosion of the reinforcing bars inserted in the concrete structure 10, and when it is less than 1 wt%, the anticorrosive effect is insignificant. When it exceeds 5 wt% But also to the above-mentioned range because the adhesion force can be lowered.

In the preparation step according to an embodiment of the present invention, a preparation process for preparing a binder aqueous solution by mixing the binder and water prepared as described above, a heating process for heating the prepared binder aqueous solution, a heating process for mixing the heated binder aqueous solution and the alkali recovery agent, A cooling process for cooling the repair material mixture, and a finishing process for manufacturing a concrete structure performance improving material by mixing silane and IPA or phosphoric acid to the mixture of the repair materials.

At this time, it is preferable to raise the temperature of the aqueous binder solution to 60 ° C during the heating process because the reaction between the binder and the alkali recovery agent is insignificant when the temperature is lowered to below 60 ° C There is a problem that the agitation takes a long time and the alkaline recovery efficiency of the concrete structure 10 is lowered.

More preferably, the heating process is preferably carried out at a temperature of 70 ° C. or lower, since the reaction between the binder and the alkali recovery agent is then exothermic if the temperature exceeds 70 ° C., the cooling process takes a long time, Which is difficult to use.

In addition, it is preferable that the cooling process is to cool the mixture of heated materials heated to 60 DEG C by the reaction between the binder and the alkali recovery agent. This is because the curing of the performance improving material of the concrete structure, which is provided while appropriately maintaining the reactivity of silane and IPA or phosphoric acid added afterward, is promoted and the maintenance time can be shortened.

When the performance improving material of the concrete structure is prepared as described above, the foreign matter in the damaged area to be repaired is removed in the pretreatment step, and then the first coating layer 100 (100) is formed on the surface of the damaged area by using a brush, ).

On the other hand, the performance improving material of the concrete structure as described above is applied to the surface of the general concrete structure to form the first coating layer 100 on the surface of the concrete structure 10, so that the aging due to the alkaline loss of the concrete structure due to ultraviolet rays and moisture The stability of the concrete structure 10 can be improved and the service life can be prolonged.

When the formation of the first coating layer 100 is completed, the repairing concrete is poured into the damaged portion in the repairing concrete pouring step to form the repairing layer 200.

The repair concrete according to one embodiment of the present invention can use general concrete, but it is more preferable to use 30 to 40 wt% of Portland cement, 50 to 60 wt% of silica, 3 to 10 wt% of swelling agent, 0.1 to 1 wt% of fluidizing agent, It is preferable to use a repair concrete prepared by mixing 1 to 10 wt% of a redispersible resin, 1 to 5 wt% of a redispersible resin, 0.01 to 0.1 wt% of an antifoamer, and 0.01 to 0.1 wt% of a homopolymer polypropylene fiber.

The above-described repair concrete is excellent in watertightness and water resistance, and is resistant to carbon dioxide and base, so that the durability and mechanical function of the concrete structure 10 can be restored.

At this time, the homopolymer polypropylene fiber exhibits a function of suppressing the occurrence of cracks by increasing the tensile strength. When the content is less than 0.01 wt%, the above effect is difficult to manifest. When the content exceeds 0.1 wt%, the cost can be increased. It is limited to the above range.

In addition, when the Portland cement exceeds the above range, cracks and the like may be generated, and if the silica added to improve the strength together with the Portland cement also exceeds the above range, the strength deterioration may occur. Limit.

On the other hand, in the case of the swelling agent used for the compensation of shrinkage of the cement, the rate of occurrence of cracks due to expansion and the case of exceeding the above range is increased, and in the case of the fluidizing agent used for securing workability When used, it causes defects such as defects. In the case of the admixture for improving the long-term strength by the pozzolanic reaction and the redispersible resin for improving the adhesion strength, the initial strength is lowered when used out of the above range, When the homopolymer polypropylene fiber for improving the antifoaming agent and the bending strength and for increasing the crack resistance is used in excess of the range described above, the workability may be lowered, so that the range is limited to the above range.

As described above, when the concrete concrete pouring step is completed, the concrete structure performance improving agent prepared in the preparation step is applied to the plane of the maintenance layer 200 to form the second coating layer 300.

Accordingly, the protection layer 200 is surrounded by the first and second coating layers 100 and 300 and exposed to external moisture and carbon dioxide to minimize aging, thereby improving the durability of the repair part and prolonging the life of the concrete structure 10 There is an effect that can be.

At this time, the second coating layer 300 may be formed on the entire surface of the concrete structure 10. Accordingly, the alkalinity of the neutralized concrete structure 10 is restored, and the direct contact between the surface of the concrete structure 10 and the outside air and moisture is minimized, so that the life and safety of the concrete structure 10 can be improved.

Meanwhile, when the second coating layer 300 is formed as described above, the coating layer 500 is formed by coating the surface of the second coating layer 300 in the finishing step.

At this time, it is preferable to use a paint selected from the group consisting of acrylic, epoxy, urethane, urea and mixtures thereof. Accordingly, it is possible to prevent moisture and carbon dioxide from flowing into the concrete structure 10 through the paint layer 500, thereby preventing aging of the concrete structure 10 and prolonging its service life.

The method for repairing concrete structures according to an embodiment of the present invention may further include the step of forming a third coating layer 400 by applying an elastic repairing material to the surface of the second coating layer 300 after the second coating layer forming step, It is preferable to further include a coating layer forming step.

The elastic repair material comprises 40 to 50 wt% of an acrylic polymer, 40 to 50 wt% of calcium carbonate, 3 to 5 wt% of titanium dioxide, 2 to 3 wt% of a thickener, 0.1 to 0.5 wt% of a wetting agent, 0.1 to 3 wt% And other impurities.

The third coating layer 400 provides an elastic force to minimize damage caused by shrinkage and expansion due to external environment such as weather. The acrylic polymer has excellent physical and chemical properties, and is excellent in adhesion strength, It is possible to improve the bonding property of the elastic repairing material and to shorten the curing time.

On the other hand, calcium carbonate is added to neutralize the acidity and to reinforce the viscosity, titanium dioxide is for imparting hue to the elastic composition and shielding ultraviolet rays, the thickening agent is for improving the viscosity and adhesion of the elastic repairing material, The pH adjusting agent is added to adjust the pH of the elastic elastic material for maintenance to be alkaline of about 12 to 14. The pH adjusting agent is added to adjust the viscosity of the elastic elastic material to alkaline, Additional auxiliaries may be added.

In addition to the above effects, titanium dioxide can improve the self-cleaning function against foreign substances and resistance to bacteria and prevent the durability from being deteriorated due to changes in physical properties, and the pH adjusting agent can control the storage stability of the elastic repair material It has an effect of enhancing compatibility and dispersibility.

More preferably, the elastic repair material according to an embodiment of the present invention may further include 0.5 to 1 wt% of fiber reinforcement 410.

At this time, the fiber reinforcing material 410 includes natural fibers such as cellulose and synthetic fibers such as polypropylene fiber, polyethylene fiber, Nylon fiber, and polyvinyl alcohol fiber. And the like can be used.

The third coating layer 400 containing the fibrous reinforcement 410 described above not only has an effect of improving the bonding force between the second coating layer 300 and the coating layer 500 but also has an insufficient tensile strength The strength and durability of the concrete structure 10 can be improved.

division Carbonation depth (mm) 1 day 7 days 14 days Comparative Example 19 20 20 Example 3 2 1.5

Table 1 shows a comparative example in which a concrete specimen of 50 mm x 50 mm x 50 mm was carbonated by using a neutralization accelerating tester and a concrete performance improver according to an embodiment of the present invention was applied to the comparative example, The depth of carbonation was measured by spraying 1% phenolphthalein solution on the cross section of the specimen after curing.

As can be seen from Table 1, when the concrete performance improving agent prepared according to one embodiment of the present invention is applied to the carbonated concrete, the alkaline property of the concrete can be restored and the performance of the concrete can be improved.

division 1 day 7 days 14 days Compressive strength
(MPa) Flexural strength
(MPa) Compressive strength
(MPa) Flexural strength
(MPa) Compressive strength
(MPa) Flexural strength
(MPa) Comparative Example 23.3 5.1 22.8 4.9 21.7 4.7 Example 29.3 7.4 30.2 7.5 32.5 7.8

Table 2 shows a comparative example in which concrete specimens of 50 mm x 50 mm x 50 mm were produced and carbonized using a neutralization accelerated tester to form cracks having a width of 10 mm and a depth of 20 mm, The results are shown in Table 1, which shows the measured compressive strength and flexural strength after repairing according to the concrete structure repair method according to the present invention.

As can be seen from Table 2, the reinforced concrete according to one embodiment of the present invention is improved in compressive strength by about 20% to 50% and flexural strength by 45% to 65% as compared with concrete after cracking after neutralization, It can be seen that it is improved.

This is because not only the strength of the crack was increased by filling the crack with the repair layer, but also the strength of the carbonated concrete was gradually restored as the curing time was increased.

As described above, according to one embodiment of the present invention, alkalinity of the aged concrete structure is lost due to loss of alkalinity, and the bending strength and compressive strength of the defected concrete structure are improved to improve the stability of the concrete structure .

Although the present invention has been described with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the following claims. It can be understood that

10: concrete structure 100: first coating layer
200: maintenance layer 300: second coating layer
400: Third coating layer 410: Fiber reinforcement
500: paint layer

Claims (9)

In the repair of the neutralized concrete structure,
A pretreatment step of removing foreign matter from a damaged area;
A first coating layer forming step of applying a performance improving material of a concrete structure to the damaged area to form a first coating layer to restore the alkalinity and strength of the concrete structure;
A repair concrete pouring step of pouring the repair concrete on the damaged area coated with the first coating layer to form a repair layer on the damaged area;
Forming a second coating layer by coating the performance improving material of the concrete structure on the surface of the conserved layer to prevent the neutralization of the conserved layer; And
And a finishing step of applying a paint selected from the group consisting of acrylic, epoxy, urethane-based urea, and mixtures thereof to the surface of the second coating layer.
The method according to claim 1,
After the second coating layer formation step,
By weight of water, 40 to 50 wt% of an acrylic polymer, 40 to 50 wt% of calcium carbonate, 3 to 5 wt% of titanium dioxide, 2 to 3 wt% of a thickener, 0.1 to 0.5 wt% of a wetting agent, 0.1 to 3 wt% And forming a third coating layer by applying an elastic repairing material including the elastic coating material on the second coating layer plane to the surface of the second coating layer.
The method of claim 2,
The elastic repairing material comprises:
And a fiber reinforcing material in an amount of 0.5 to 1 wt%.
The method according to claim 1,
Before the preprocessing step,
Preparing a concrete structure performance improving material composed of 15 to 20 wt% of an alkali restorer, 45 to 55 wt% of a binder, 1 to 5 wt% of silane, 1 to 5 wt% of IPA (icosapentaenoic acid) or phosphoric acid and 30 to 50 wt% of water; Further comprising the steps of:
The method of claim 4,
In the preparation step,
Preparing a binder aqueous solution by mixing the binder and water to prepare a binder aqueous solution;
A heating process of heating the binder aqueous solution to 60 占 폚;
A stirring step of adding an alkaline recovery agent to the heated aqueous binder solution and stirring the primary to prepare a maintenance agent mixture;
A cooling process for cooling the maintenance material mixture to 60 캜; And
And a finishing step of adding the silane, IPA or phosphoric acid to the maintenance material mixture, and stirring the secondary material to prepare the performance improving material for the concrete structure.
The method of claim 4,
Wherein the binder comprises:
Lithium silicate, sodium silicate, and potassium silicate, and the alkali recovery agent is one selected from potassium hydroxide or sodium hydroxide.
As a performance improving material for a concrete structure to repair a neutralized and damaged concrete structure,
Wherein the composition contains 20 to 40 wt% of an alkali recovery agent, 15 to 20 wt% of a binder, 0.5 to 5 wt% of silane, 1 to 5 wt% of IPA (icosapentaenoic acid) or phosphoric acid, and 30 to 50 wt% of water.
The method of claim 7,
The alkali-
Potassium hydroxide or sodium hydroxide, and having a pH of from 12 to 14. The present invention relates to a concrete improvement agent for improving the performance of a concrete structure.
The method of claim 7,
Wherein the binder comprises:
Lithium silicate, sodium silicate, potassium silicate, and mixtures thereof. ≪ RTI ID = 0.0 > 11. < / RTI >

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