KR102018768B1 - Coating material for protecting surface of concrete structure and method for repairing concrete structure using this same - Google Patents

Abstract

The present invention relates to a coating agent composition for protecting a surface of a concrete structure and a method for repairing a concrete structure using the same, wherein the coating agent composition is configured to increase bonding strength with the concrete structure, thereby preventing peeling of a coating layer and to secure flexibility for construction of the concrete structure, thereby improving durability of the coating layer and protecting the concrete structure for a long time. The coating agent composition for protecting a surface of a concrete structure of the present invention is obtained by mixing 33-40 wt% of calcium carbonate, 20-26 wt% of acrylic latex, 20-25 wt% of water, 0.6-0.8 wt% of a dispersant, 0.05-0.2 wt% of surfactant, 0.5-2.0 wt% of an anti-foaming agent, 0.3-1.0 wt% of a thickener, 0.05-0.2 wt% of preservatives, 0.1-0.4 wt% of an anti-freezing agent, 0.4-1.5 wt%, of a plasticizer, 10-15 wt%, of pigment, and 0.3-1.0 wt% of a diluent. According to the method for repairing a concrete structure using the coating agent composition for protecting a surface of a concrete structure of the present invention, there are a method of directly coating a surface protection layer by applying the coating agent composition for protecting a surface of a concrete structure to the surface of a concrete structure, and a method of forming a primer layer by applying primer to the surface of a concrete structure, forming a repairing layer by applying a crack repairing agent to the primer layer, and coating the surface protection layer by applying the coating agent composition for protecting a surface of a concrete structure to the repairing layer.

Description

COATING MATERIAL FOR PROTECTING SURFACE OF CONCRETE STRUCTURE AND METHOD FOR REPAIRING CONCRETE STRUCTURE USING THIS SAME}

The present invention relates to a coating agent for protecting the surface of concrete, and more particularly, to increase the adhesion strength with the concrete structure to prevent peeling of the coating layer and to improve the durability of the coating layer through securing the flexibility for the expansion and expansion of the concrete structure It relates to a concrete protective coating composition that can protect the structure for a long time and a method for repairing the concrete structure using the same.

This section provides background information related to the present application but is not necessarily prior art.

Concrete structures are widely used as construction materials for semi-permanent structures because of their excellent durability. However, when the concrete structure is exposed to the marine environment for a long time, the concrete is eroded by the action of sea water (sea breeze), the reinforcing steel is corroded, and the concrete is cracked and peeled off due to the volume expansion. Will be degraded. In addition, in winter, concrete may be damaged due to freezing and thawing, and in the case of prolonged exposure to automobile exhaust gases, internal reinforcing steel may be corroded and neutral or cracked or dropped due to neutralization.

In addition to these causes, deterioration, neutralization of the concrete structure, alkali aggregate reaction, factory wastewater and domestic sewage, etc. can also be corroded and damaged concrete.

In the case where the internal reinforcing steel is corroded by the various causes and the concrete is cracked or dropped, it is necessary to restore it to its original state in order to continue to use the structure stably. Is being used by.

Patent documents for protecting the surface of concrete structures are as follows.

Patent document (Registration No. 10-1893380) is an environmentally friendly protective agent composition for protecting the surface of a concrete structure in a harsh environment, comprising 1 to 75% by weight of the modified filler and 25 to 99% by weight of the modified admixture, the modified filler 25 to 95% by weight of heavy calcium carbonate (Ground Calcium Carbonate), 1 to 30% by weight of silicon carbide, 1 to 30% by weight of mullite, 1 to 20% by weight of titanium oxide, 1 to 20% by weight of mica, aluminum titanic acid 0.1 to 15% by weight and 0.1 to 15% by weight of beryllium oxide, wherein the modified admixture is 25 to 99% by weight of methyl methacrylate-acrylonitrile copolymer, 0.1 to 35 ethylene oxide-propylene oxide polymer Weight percent, polyvinylidene fluoride 0.1-20 wt%, 3-hydroxypropyl acrylate 0.1-15 wt%, vinyl ester 0.1-15 wt% and methylphenylpolysiloxane 0.1-15 wt%.

Patent Registration No. 10-1893380

The present invention is to solve the problems as described above, to prevent the peeling of the coating layer by increasing the adhesion strength with the concrete structure, and to improve the durability of the coating layer through securing the flexibility for the expansion and contraction of the concrete structure and to protect the concrete structure for a long time The purpose of the present invention is to provide a concrete protective coating composition and a method for repairing concrete structures using the same.

Concrete protective coating composition according to the present invention, 33-40% by weight calcium carbonate, 20-26% by weight acrylic latex, 20-25% by weight water, 0.6-0.8% by weight dispersant, 0.05-0.2% by weight surfactant, antifoam 0.5 ~ 2.0% by weight, thickener 0.3-1.0% by weight, preservative 0.05-0.2% by weight, cryoprotectant 0.1-0.4% by weight, plasticizer 0.4-1.5% by weight, pigment 10-15% by weight, diluent 0.3-1.0% by weight Characterized in that made.

The present invention is characterized in that it further comprises a fiber reinforcement for preventing the crack of the protective coating layer.

The fiber reinforcement is characterized in that it is arranged on the bottom side of the protective coating layer through the sedimentation induction.

According to the concrete protective coating composition according to the present invention and a method for repairing a concrete structure using the same, acryl latex penetrates into the pores of the concrete structure to increase the bonding strength between the concrete structure and the protective layer to prevent damage to the concrete structure due to the peeling of the protective layer. In addition, by using the flexibility of the protective coating layer to prevent the cracks of the protective coating layer due to the stretching behavior of the concrete structure has the effect of long-term protection of the concrete structure.

In addition, even if a behavior such as stretching occurs due to the temperature change of the concrete structure, the protective coating layer is protected by mixing the fiber reinforcement, thereby preventing the foreign matter from penetrating the cracked portion of the concrete structure.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The concrete protective coating composition according to the present invention is composed of calcium carbonate, acrylic latex, water, dispersant, surfactant, antifoaming agent, thickener, preservative, cryoprotectant, plasticizer, pigment, diluent, and the mixing ratio of these materials is protective coating agent. The mixing ratio is based on 100% by weight of the total composition.

Calcium carbonate is a filler of calcium carbonate, which can be obtained from marble, calcite, ore, limestone, chalk, ice tin, shells, egg shells, corals, etc. As the amount of material increases, an imbalance occurs, and an amount of more than 40% by weight impairs concrete protection.

Acrylic latex (acrylic latex) is used for crack resistance, flexibility, adhesion, and low temperature stability. For example, fine powder having a particle size of 0.1 to 0.5 µm may be used, and for example, a crosslinking agent is mixed by emulsion polymerization of an acrylic monomer. The crosslinking agent is ammonium polyacrylate consisting of an emulsion polymer of an ammonium persulfate and an acrylic acid derivative selected from acrylic acid or methacrylic acid homopolymers, maleic anhydride or copolymers with itaconic acid.

Acrylic latex penetrates into the pores of concrete structures, increasing adhesion and water resistance.

Acrylic latex is mixed 20 ~ 26% by weight, if less than 20% by weight, the adhesion strength is weak, the crack resistance due to external factors is weak, and the excess of 26% by weight can be less workability without difference in the protective effect of concrete. have.

Water is used for the mixing of the materials and the workability and the protective coating properties are inferior when the mixing ratio is 20-25% by weight. Materials other than water are supplied in a mixed state, and water and the remaining materials are mixed and used at the repair site of the concrete structure.

The dispersant prevents agglomeration and dispersion of the materials, leading to uniform mixing. Less than 0.6% by weight of the dispersant has a weak dispersion effect and more than 0.8% by weight of the dispersing effect.

Surfactants are used to reduce the surface tension between materials to prevent precipitation of solids, to improve dispersibility, and to uniformly mix the materials. 0.05 to 0.2% by weight is the optimal value for effective function.

The antifoaming agent is used for the purpose of removing bubbles, and is appropriately mixed with foaming ethanol (ethyl alcohol) and silicone oil which suppresses foaming. Preferably, the antifoaming agent is mixed at a weight ratio of 1: 1, and the total amount is 0.5 to 2.0% by weight.

The thickener ensures workability by controlling the viscosity of the material (increasing viscosity), and if it is outside 0.3 ~ 1.0% by weight, the physical property is diminished to low viscosity, resulting in poor workability and, on the contrary, uniform mixing of materials with high viscosity is difficult.

Pigment is to give a color to the concrete structure by expressing the coating layer of the protective coating color, various kinds are selected and used, 10 ~ 15% by weight is the optimal mixing ratio for the color representation. Pigments may be used by mixing two kinds of different colors, and the ratio is the mixing ratio of the whole pigments.

Preservatives are used for the purpose of preventing alteration of the protective coating, and 0.05 to 0.2% by weight is an optimal mixing ratio for material preservation.

The cryoprotectant prevents the protective coating from freezing in winter, and 0.1 to 0.4% by weight is the optimal mixing ratio to prevent deterioration of the protective coating and to prevent freezing.

Plasticizer is used in 0.4 ~ 1.5% by weight for plasticity, heat resistance and cold resistance.

The diluent is used for the purpose of dissolving the material or adjusting the viscosity, and a mixing ratio of 0.3 to 1.0% by weight is a ratio for achieving the above object.

Repair method of the concrete structure using the concrete protective coating composition according to the present invention is to wash the surface of the concrete structure (both dry and wet, need to dry when wet cleaning)-coating the concrete protective coating composition of the present invention (surface protective layer formation) The process is done.

Repair method of the concrete structure using the concrete protective coating composition according to the present invention, otherwise, the surface of the concrete structure (both dry and wet, can be dried when wet cleaning)-primer coating (primer layer formation)-crack repair agent coating (Repair layer formation)-It consists of the process of application | coating (surface protective layer formation) of the concrete protective coating composition of this invention. The primer and crack repair agent can be used for all known products.

<Example>

Composition (% by weight)

Calcium carbonate Acrylic Latex water Dispersant Surfactants Antifoam 37 24 22 0.7 0.1 0.9 Thickener Pigment antiseptic Cryoprotectants Plasticizer diluent 0.5 13.4 0.1 0.2 0.6 0.5

2. Manufacture

The materials in the composition of Table 1 are placed in a mixer and mixed to prepare a protective coating.

3. Testing.

A concrete structure (width ㅧ height 30 height, 30 cm ㅧ 30 cm ㅧ 10 cm) was prepared, and the protective coating of the present invention was applied to the surface of the concrete structure to form a protective coating layer. The thickness of the protective coating layer was 3 mm. Protective coatings can range in thickness from 0.5mm to 7mm.

As a comparative example for comparison with the present invention, a general concrete structure (the same structure as this example, but without a protective coating layer on the surface) was prepared, and the present example and the comparative example were tested under the same conditions.

end. Pitcher characteristics.

As a result of the permeability test, the comparative example was visually confirmed that water is permeable, but this example was confirmed that the water is not permeable.

I. Low temperature cracking properties.

After the Example and Comparative Example were placed in the chamber at minus 20 ° C. for the same time period (3 days), the Comparative Example showed cracks, but this Example did not show cracking.

All. Pollution characteristics.

The same type of paint was applied to the surface of the present example and the comparative example and then washed with water. As a result, the comparative example was found to leave traces of the paint, whereas the present example did not show traces of the paint.

The present invention may further include a fiber reinforcing material for preventing cracks.

The fiber reinforcing material is made of nylon or aramid yarn with excellent tensile strength to prevent cracking of the protective coating layer, and preferably has a length of 0.5 to 3 mm (reuse of discarded fibers) and is based on 100 parts by weight of the total protective coating agent of the present invention. 3-15 weight part is mixed.

The fiber reinforcement has a weak reinforcing effect at less than 3 parts by weight and excessive use at over 15 parts by weight, thereby reducing the effective function of other materials.

The fiber reinforcement may damage the aesthetics when exposed to the outside and is used after the pigment of the same color as the pigment is coated, that is, since the protective coating layer and the fiber reinforcement appear to be the same color, it does not cause aesthetic damage due to the fiber reinforcement. Even when the pigment of the coating agent is used in a small amount, the color of the fiber reinforcement material is visible, thereby causing optical illusion, and the protective coating layer may be displayed in a desired color.

In addition, the settling inducer may be used together so that the fiber reinforcement is concentrated on the surface side of the concrete structure without floating on the surface side of the protective coating layer.

The sedimentation inducing agent is to allow the fiber reinforcement to sink in water, i.e., beneath other materials, and mud or silica can be used, and the fiber reinforcement is used by bonding one or more of the mud and silica sand to the surface. In addition, the coating of the protective coating layer is adhered to the surface of the concrete structure at the bottom of the protective coating layer to solve the shortcomings caused by external exposure and reduce the loss in the protective coating layer. The settling inducing agent is adhered to the fiber reinforcing material before the pigment is painted to make the color of the pigment visible.

The sedimentation inducing agent is determined by the particle size and the amount of free use and the amount used to achieve the purpose of inducing sedimentation of the fiber reinforcement and the amount of fiber reinforcement.

In the present invention, calcium chloride may be further applied in winter to remove snow on the surface of the concrete structure.

The calcium chloride is commonly used in the form of a powder and is concentrated and applied to the surface of the protective coating layer through a specific gravity control agent to increase the snow removal effect. Preferably, calcium chloride is used after being bound to a powder of aerogel, foam (urethane, etc.) floating in water due to its low specific gravity through a binder (adhesive). The calcium chloride is a powder having a particle size smaller than the thickness of the protective coating layer and 3 to 7 parts by weight based on 100 parts by weight of the total protective coating agent is used, the mixing ratio is a mixing ratio for snow removal without destroying the effective properties of the protective coating layer. The mixing ratio of the calcium chloride and the specific gravity regulator can be variously changed under the premise of concentrating calcium chloride on the surface of the protective coating layer.

Embodiments in which the fiber reinforcing material and calcium chloride are mixed in the present invention were also shown to exhibit properties similar to the permeability characteristics, low temperature cracking characteristics, and contamination characteristics of the concrete protective coating composition of the above-described embodiment.

In the present invention, it is also possible to coat a single material in which the fiber reinforcement and the whole calcium chloride are mixed in a single operation, or apply the fiber reinforcement (including the adhesive) first, and then apply the mixture of the remaining materials (except calcium chloride), and finally calcium chloride (including the adhesive). It is also possible to apply).

Claims (5)

33-40 wt% calcium carbonate, 20-26 wt% acrylic latex, 20-25 wt% water, 0.6-0.8 wt% dispersant, 0.05-0.2 wt% surfactant, 0.5-2.0 wt% defoamer, 0.3-1.0 wt% thickener %, Preservative 0.05-0.2% by weight, cryoprotectant 0.1-0.4% by weight, plasticizer 0.4-1.5% by weight, pigment 10-15% by weight, diluent 0.3-1.0% by weight
While mixing 3 to 15 parts by weight of the fiber reinforcement with respect to 100 parts by weight of the concrete protective coating composition, while the fiber reinforcement is settled in the protective coating layer through the coating of mud or silica as a sediment inducing agent to concentrate on the surface of the concrete structure, 3 to 7 parts by weight of calcium chloride is mixed with respect to 100 parts by weight of the concrete protective coating composition, wherein the concrete is characterized in that the calcium chloride is concentrated on the surface of the protective coating layer through a specific gravity control agent bound to a powder of aerogel or urethane foam. Coating composition. delete The method of claim 1, wherein the fiber reinforcing material is coated with a pigment of the same color as the pigment on the surface on which the sedimentation induction agent is coated or after the sedimentation induction agent is coated with a pigment of the same color as the pigment is coated on the fiber reinforcement Concrete protective coating composition. delete Applying the concrete protective coating composition according to claim 1 on the surface of the concrete structure to coat the surface protection layer, or by applying a primer on the surface of the concrete structure to form a primer layer and to apply a crack repair agent to the primer layer to form a repair layer After the concrete protective coating composition according to claim 1 to the repair layer to the concrete structure repair method using a concrete protective coating composition, characterized in that for coating the surface protective layer.