KR102402144B1 - Coating method for neutralization prevention and energy saving of a concrete structure - Google Patents

Abstract

The present invention relates to a coating method for preventing neutralization and saving energy of a concrete structure, the method comprising: a pretreatment step (S10) of arranging a surface of a raised area of concrete and a deteriorated surface of the existing paint; a concrete neutralization prevention step (S20) of applying an organic-inorganic composite waterproofing agent mixed with EVA waterproofing agent containing soluble silicate: water: cement in a weight ratio of 1: 1 to 1.5: 1 to 1.5 on a surface of the concrete to a thickness of 1 to 2 mm; a water-soluble undercoating step (S30) of applying an acrylic emulsion primer to a thickness of 30 to 70 μm after the organic-inorganic composite waterproofing agent is dried; and an aqueous thermal blocking coating step (S40) of applying a silicone acrylic emulsion-based thermal blocking coating to a thickness of 0.1 to 0.3 mm on the cured acrylic emulsion primer. The present invention is an environmentally friendly coating method that does not use organic solvents at all, and applies permeable waterproofing treatment to concrete by applying the EVA waterproofing agent containing soluble silicate and the cement-based organic/inorganic composite waterproofing agent to the surface of the concrete, thereby preventing neutralization of the concrete by increasing a density of a concrete surface layer and chemically stabilizing the surface. In addition, the present invention has an excellent effect on improving durability of the concrete and thermal blocking properties by applying the acrylic emulsion primer with excellent compatibility to strengthen interlayer adhesion, and then sequentially applying the silicone acrylic emulsion-based thermal blocking coating on a top thereof.

Description

Coating method for neutralization prevention and energy saving of a concrete structure

The present invention relates to a method for preventing neutralization and energy saving of concrete structures, and more particularly, by applying an organic/inorganic composite waterproofing agent based on EVA waterproofing agent on a base surface of concrete to prevent neutralization of concrete, and to improve adhesion It relates to a method for preventing neutralization of concrete structures and saving energy by applying an excellent acrylic emulsion primer and then applying a silicone acrylic emulsion-based thermal barrier paint on the upper part, thereby preventing neutralization of a concrete structure by an environmentally friendly painting method.

In general, a building constructed of concrete undergoes repeated summer and winter seasons every year, and the freezing or corrosion of infiltrated water due to temperature changes or deterioration due to atmospheric or sunlight occurs. Waterproofing is essential to block moisture and heat.

Since the concrete used in these structures is hardened through a hydration reaction in which cement and water react by adding aggregates such as sand and gravel to cement and water, calcium hydroxide (Ca(OH) ₂ ) generated by the hydration reaction takes time. As time goes by, corrosion is caused to reinforcing bars due to neutralization in which alkalinity is lost due to a chemical reaction by carbon dioxide and moisture, that is, carbonation that changes to calcium carbonate (CaCO ₃ ) {Ca(OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O}, and salt damage or alkali-silica reaction that causes cracks in concrete by reacting and expanding in the presence of moisture between highly alkaline cement and certain aggregates, etc. The lifespan of the concrete structure is shortened due to the combined deterioration action.

In the above concrete structures, the most harmful cause of deterioration in durability due to deterioration and freezing and thawing by external environments such as acid rain, air pollution, ultraviolet rays, CO ₂ gas, and use of calcium chloride in winter is neutralization of concrete over a long period of time. As water or air enters, the internal rebar corrodes and rust occurs, causing micropores and cracks on the surface.

This phenomenon occurs when the concrete structure is exposed to air and moisture, and when the internal pH is 12 to 13, or about 11 or higher, a passivation film is formed on the surface of the reinforcing bar, so it is not easily rusted even in the presence of oxygen, but due to neutralization, the pH is lower than 11, When it falls below about 8.5 to 10, rust occurs in the reinforcing bar, and the reinforcing bar expands in volume by about 2.5 times due to this corrosion. Eventually, deterioration (aging) proceeds rapidly.

In order to prevent corrosion and neutralization of the concrete structure, a paint is applied to the concrete structure to form a coating film, thereby preventing the penetration of air, moisture, and the like. However, conventional paint compositions use organic solvents to absorb organic substances into the human body, thereby affecting the central nervous system and threatening the health of workers or users. Also, most organic solvents are volatile, so harmful substances are emitted into the atmosphere. Since the problem is serious, research on an eco-friendly paint composition and coating method that can prevent the neutralization of current concrete structures is continuously being made.

On the other hand, in modern times, in order to maintain a comfortable indoor environment, a constant indoor temperature is maintained by using an air conditioner inside a building. Accordingly, a method for maintaining the temperature of the building and preventing energy loss by applying a heat-shielding paint or an insulating paint to the outer wall of the building has been widely applied.

The most important function of the thermal barrier paint is solar reflectance, and in the case of a building painted with a thermal barrier paint with a high solar reflectance, the heat entering the room is greatly reduced to keep the indoor temperature low. Significant energy savings can be expected by painting on a roof or wall where insulation is not installed. These heat-shielding paints are sometimes confused with heat-insulating paints that use low thermal conductivity, but paints capable of exhibiting heat-shielding and heat-insulating properties in combination are also used depending on their function.

Therefore, in the present invention, by applying an organic/inorganic composite waterproofing agent based on EVA waterproofing agent to the base surface of concrete by an environmentally friendly coating method that does not use any organic solvents, an acrylic emulsion primer, which is a water-soluble primer, is applied to strengthen adhesion. Next, a coating method for concrete structures that can prevent neutralization and save energy at the same time was developed by applying silicone acrylic emulsion-based thermal barrier paint in stages.

Looking at the typical prior art for improving the durability and heat shielding properties of concrete structures as described above, Korean Patent No. 10-1740239 discloses at least one water-based polymer from among water-soluble polyurea resins, water-soluble acrylic resins, water-soluble epoxy resins, and water-based EVA resins. Based on 100 parts by weight of the resin, 25 to 75 parts by weight of an alkaline aqueous solution, 25 to 75 parts by weight of an extender, 5 to 30 parts by weight of a pigment, 20 to 75 parts by weight of water, 2 to 5 parts by weight of a wetting and dispersing agent, 2 to 5 parts by weight of an antifoaming agent , 5 to 30 parts by weight of lithium hydroxide for fixing carbon dioxide leaked by the antifoaming agent, and 2 to 5 parts by weight of disteadimonium hectorite in which the thickening effect is expressed after a certain time has elapsed; Based on 100 parts by weight of the organic-inorganic composite resin, 25 to 75 parts by weight of a water-soluble polymer resin, 25 to 75 parts by weight of an extender pigment, 5 to 30 parts by weight of a pigment, 20 to 75 parts by weight of water, 2 to 5 parts by weight of a wetting and dispersing agent, an antifoaming agent 2 To 5 parts by weight, a top coat containing 2 to 5 parts by weight of disteadimonium hectorite, which exhibits a thickening effect after a certain period of time; neutralization and Disclosed is a coating agent for protecting concrete structures with improved salt damage prevention function.

In addition, Korean Patent No. 10-1925220 discloses (1) the first step of arranging the construction surface to be constructed; (2) a second step of first applying a coating solution containing a methyl methacrylate (MMA) resin, a peroxide-based curing agent, and an additive to the construction surface, and reacting it to apply a primer; (3) a third step of laying a synthetic resin tissue having a weight per unit area of 10 to 1000 g/m ² , a tensile force of 10 to 1000 N/50 mm and a thickness of 0.05 to 1.0 mm thereon after applying the undercoat; (4) a fourth step of applying and curing a primary surface protection material comprising an acrylic resin, a rubber chip, an airgel and a powder component on the synthetic resin tissue; and (5) a second surface protection material containing 100 parts by weight of a liquid component containing a methyl methacrylate (MMA) resin and 30 to 300 parts by weight of an inorganic powder component on top of which the primary surface protection agent is applied and cured. 5th step; including, wherein the synthetic resin tissue of (3) uses a thin film of polyamide or polyester-based resin, and the powder component of (4) is mica having a particle diameter of 1 to 100 μm 5 to 40 parts by weight, 10 to 50 parts by weight of stone dust, and 1 to 10 parts by weight of titanium oxide It relates to a method of constructing a flooring for waterproofing, anti-corrosion and neutralization prevention containing MMA resin, characterized in that it uses a mixture.

Recently, as a method of constructing an anti-neutralization composite sheet using a water-soluble acrylic urethane waterproofing agent according to Korean Patent No. 10-2200896, (a) foreign substances adhering to the surface and corners of the roof or roof floor and walls of the building to be waterproofed are removed. a repair step of removing and repairing cracks or dents; (b) applying a water-soluble acrylic urethane waterproofing agent to the surface of the floor and wall by mixing a certain amount of water and applying it at a rate of 0.3 to 0.4Kg/m ² using a painting brush or roller; (c) when the applied waterproofing layer is completely dried, a reinforcing step of constructing a corner portion between the floor and the wall and the wall using a composite sheet and a water-soluble acrylic urethane waterproofing agent; (d) when the reinforcing part is completely dried after the reinforcing step is completed, applying a water-soluble acrylic urethane waterproofing agent to the floor using a painting brush or roller to apply a first intermediate waterproofing layer; (e) a composite sheet bonding step of constructing the composite sheet in a predetermined direction on the applied first intermediate waterproofing layer; (f) Water-soluble acrylic urethane waterproofing agent is mixed with water-soluble acrylic urethane waterproofing agent by mixing 10-20L of water to adjust the viscosity with 20Kg of water-soluble acrylic urethane waterproofing agent, and applying the diluted water-soluble acrylic urethane waterproofing agent on the constructed composite sheet at 0.4-0.6Kg/m ² Applying an impregnated waterproof layer to be impregnated into the sheet; (g) when the applied impregnated waterproofing layer is completely dried, a second intermediate waterproofing layer coating step of applying a water-soluble acrylic urethane waterproofing agent at 0.4 to 0.6Kg/m 2 using a painting brush or roller; (h) when the applied secondary waterproofing layer is completely dried, applying a water-soluble acrylic urethane waterproofing agent at 0.4 to 0.6Kg/m 2 using a painting brush or roller thereon; (i) When the applied tertiary waterproofing layer is completely dried, apply a water-soluble acrylic urethane waterproofing agent mixed with acrylic to 20Kg of water-soluble acrylic urethane waterproofing agent in a ratio of 10-20Kg using a paint brush or roller to 0.4-0.6Kg/ It includes a step of applying a top coat layer applied in m2.

And, looking at Korean Patent No. 10-2207388, as a heat-shielding waterproof coating method for forming a waterproof coating composed of an undercoat layer, a heat insulating layer, a heat shield layer and a transparent UV protective layer on the roof, (1) a base material layer for a roof is treated or Preparing an undercoating layer by water-repellent coating treatment, (2) on the undercoating layer, 0.1 to 2% by weight of a hollow pigment, 1 to 5% by weight of a white pigment, 20 to 40% by weight of an extender pigment, 40 to 60% by weight of an elastic binder resin Forming a heat insulating layer by applying and drying an aqueous heat insulating paint containing 1 to 5 wt % of a diluent, 5 to 15 wt % of an additive, and the remaining amount of water, (3) A heat insulating pigment containing aluminum metal powder 0.1 on the heat insulating layer - 2 wt%, 20-40 wt% white pigment, 40-60 wt% acrylic binder resin, 1-5 wt% diluent, 5-15 wt% additive, and water-based heat shielding paint containing the remaining amount of water is applied and dried It consists of a step of forming a heat shielding layer, (4) further applying a transparent UV protective layer on the heat shielding layer.

Republic of Korea Patent Publication No. 10-1740239 (announcement date May 29, 2017) Republic of Korea Patent Publication No. 10-1925220 (announcement date December 04, 2018) Republic of Korea Patent Publication No. 10-2200896 (announcement date January 08, 2021) Republic of Korea Patent Publication No. 10-2207388 (published on January 26, 2021)

An object of the present invention is to provide an environmentally friendly coating method that does not use any organic solvents, and by applying an EVA waterproofing agent containing soluble silicate and cement-based organic-inorganic composite waterproofing agent to the base of concrete, watertightness by penetrating waterproofing treatment Prevents the neutralization of concrete by increasing it, strengthens the interlayer adhesion by applying an acrylic emulsion primer with excellent compatibility, and then gradually applies a silicone acrylic emulsion-based heat shielding paint on the upper part to prevent neutralization of concrete structures and save energy It provides a method of painting.

The neutralization prevention and energy-saving painting method of a concrete structure as in the present invention, a pre-treatment step (S10) of cleaning up the raised area of the concrete base and the deteriorated existing paint surface; Concrete neutralization prevention step ( S20); After the organic-inorganic composite waterproofing agent is dried, a water-soluble undercoating step of applying an acrylic emulsion primer to a thickness of 30 ~ 70㎛ (S30); and a water-based thermal barrier coating step (S40) of applying a silicone acrylic emulsion-based thermal barrier coating to a thickness of 0.1 to 0.3 mm on the cured acrylic emulsion primer.

According to a preferred embodiment of the present invention, the EVA waterproofing agent is ethylene-vinyl acetate copolymer (Ethylene-Vinyl Acetate Copolymer) 50 to 80% by weight, and at least one soluble silicate selected from sodium silicate, potassium silicate, and lithium silicate 20 ~ It is composed of 50% by weight, and the acrylic emulsion primer is applied to the surface to be coated by diluting an acrylic emulsion having a solid content of 25 to 35wt% and water in a volume ratio of 1:2-4, and curing it at room temperature for 2-3 hours. characterized.

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And the silicone acrylic emulsion-based heat shielding paint is 15 to 25% by weight of water, 40 to 50% by weight of silicone acrylic emulsion, 15 to 25% by weight of titanium dioxide, 5 to 10% by weight of limestone powder, 5 to 10% by weight of amorphous synthetic silica gel It is characterized in that it is composed of a ratio.

The neutralization prevention and energy-saving coating method of the concrete structure according to the present invention is an environmentally friendly coating method that does not use any organic solvent, and an organic-inorganic composite based on cement and EVA waterproofing agent containing soluble silicate on the surface of concrete By applying a waterproofing agent to perform penetrative waterproofing treatment on concrete, the density of the concrete surface layer is dense and chemically stabilized to prevent neutralization of concrete. After reinforcing, the silicone acrylic emulsion-based heat shielding paint is applied step-by-step on the upper part, thereby improving the durability of concrete and providing excellent heat shielding properties.

1 is a process flow chart showing a coating method according to the present invention.

Hereinafter, the neutralization prevention and energy-saving coating method of the concrete structure according to the present invention will be described, which is intended to illustrate to the extent that a person of ordinary skill in the art to which the present invention pertains can easily implement the invention. However, this does not mean that the technical spirit and scope of the present invention is limited.

As shown in Figure 1, the neutralization prevention and energy saving coating method of a concrete structure according to the present invention, a pretreatment step (S10) of arranging the raised area of the concrete base and the deteriorated existing paint surface; Concrete neutralization prevention step ( S20); After the organic-inorganic composite waterproofing agent is dried, a water-soluble undercoating step of applying an acrylic emulsion primer to a thickness of 30 ~ 70㎛ (S30); The water-based thermal barrier coating step (S40) of applying a silicone acrylic emulsion-based thermal barrier coating to a thickness of 0.1 to 0.3 mm is performed on the cured acrylic emulsion primer.

First, the pretreatment step (S10) is a process of arranging the raised area of the concrete base and the deteriorated existing paint surface. In the case of high-strength concrete, adhesion failure may occur during grinding, so the surface treatment is performed using a blasting method. Adhesion performance can be improved by carrying out , and gaps, grooves, cracks, etc. can be filled with epoxy putty after V-cutting and then polished to improve adhesion with a waterproofing agent and waterproof performance.

Next, in the concrete neutralization prevention step (S20), an organic-inorganic composite waterproofing agent mixed with EVA waterproofing agent containing soluble silicate: water: cement in a weight ratio of 1:1 to 1.5: 1 to 1.5 on the base surface of the pretreated concrete It is a process of coating with a thickness of 1 to 2 mm, and the EVA (Ethylene-Vinyl Acetate, ethylene vinyl acetate) is a new material combining ethylene and vinyl acetate. It is widely used in various applications such as sheets.

The basic properties of the EVA resin include high light transmittance and excellent tensile and elongation, as well as excellent weather resistance because it does not harden well at low temperatures and does not soften even at high temperatures, and has strong chemical resistance and no gas generation or toxicity. Because it is water-soluble, it was selected based on the fact that it has very good compatibility with soluble silicate that can be dissolved in water among many waterproofing agents.

On the other hand, when concrete is cured, calcium silicate hydrate (CSH) is formed and strength is expressed, but calcium hydroxide and ettringite are produced together as by-products, causing subsequent deterioration of concrete. In addition, the cured concrete is porous, so calcium hydroxide (Ca(OH) ₂ ) on the concrete surface easily meets with moisture, CO ₂ gas, and acidic pollutants in the air to neutralize it. As a result, corrosion progresses from the concrete surface and serious structural defects This may result in

To prevent this phenomenon, if the concrete surface is treated with a component that can be integrated with the concrete so that it does not easily react with moisture, CO ₂ gas, and acidic pollutants in the air, it can protect the concrete and prolong its life. The soluble silicate contained in the EVA is a compound in which silica (SiO ₂ ) and alkali metal oxide (M ₂ O) are combined in various molar ratios, and generally contains some water in the structure, so M ₂ O-nSiO ₂ -xH It is expressed in the molecular formula of ₂ O, and is called soluble silicate or water glass because of its solubility in water. Depending on the type of alkali metal, sodium silicate (sodium silicate), potassium silicate (potassium silicate) , lithium silicate (lithium silicate), and the like.

For reference, sodium silicate or potassium silicate, etc. melts in water with high-pressure steam when silica sand (SiO ₂ ) is melted with Na ₂ CO ₃ or K ₂ CO ₃ at 1100 ~ 1200℃ to form a transparent and slightly viscous liquid However, soluble silicate (water glass) dissolved in water can exhibit various properties depending on the molar ratio of silica to alkali metal and the concentration of the solution.

Alkali metal ions constituting the soluble silicate used in the present invention, particularly Na ⁺ , K ⁺ , and Li ⁺ ions, have very high reactivity and react very quickly with acidic or ionic substances to have alkali buffering ability, which It chemically reacts with unreacted calcium hydroxide (Ca(OH) ₂ ) to generate insoluble calcium silicate hydrate (CSH) in the pores of the concrete, and as it is integrated with the concrete, the surface layer density, strength and chemical resistance of concrete are improved. .

Accordingly, the soluble silicate used in the present invention is a liquid compound in which silica (SiO ₂ ) and one or more alkali metal oxides (M ₂ O) selected from Na ⁺ , K ⁺ , and Li ⁺ are combined, and the total weight of the EVA waterproofing agent It was confirmed that the content within the range of 20 to 50% by weight based on the EVA resin was mixed with the EVA resin and penetrated well into the pores and microcracks of the concrete surface. The bonding does not cause any particular change in the appearance of the coated surface.

In addition, the EVA waterproofing agent containing the soluble silicate is mixed with water and cement in a weight ratio of 1:1 to 1.5: 1 to 1.5 to prepare an organic-inorganic composite waterproofing agent, which is applied to the concrete surface to a thickness of 1 to 2 mm. As the base surface is formed densely and flat, the durability of the concrete structure can be increased by preventing the neutralization and deterioration of the concrete for a long period of time.

The EVA waterproofing agent prepared as described above is a transparent liquid, and the quality test results for the EVA waterproofing agent are shown in [Table 1] below.

Test Items Properties pH 11 to 12 Specific gravity (25℃) 1.1 to 1.2 Solid content (wt%, 250℃, 1Hr) 27±1 Viscosity (cps, 25℃) Max. 30

The EVA waterproofing agent is preferably used at about 0.2L/m2 for new concrete with a strength of 250kgf/cm2 or more, and about 0.3L/m2 for old concrete or concrete with a strength of less than 250kgf/cm2. Of course, the actual amount used may vary depending on the pores of the concrete.

Next, in the water-soluble undercoating step (S30), after the inorganic waterproofing agent composition is dried, an acrylic emulsion primer is applied to a thickness of 30 to 70 μm, which improves the bondability with the heat shielding paint applied thereon. In order to improve it, by controlling the viscosity and application thickness of the acrylic emulsion primer suitable for the application site of the concrete structure, it can serve to better maintain the adhesion strength and durability between the organic-inorganic composite waterproofing agent and the thermal barrier coating.

The acrylic emulsion primer is a material suitable as a pretreatment agent for cement and repair coating buildings, and since it is an alkaline substrate containing acrylic emulsion as a main component, it can effectively prevent whitening and weathering of concrete, which has a solid content of 25 to 35 wt%. By diluting the acrylic emulsion and water in a volume ratio of 1: 2 to 4 times, and applying it to the surface to be coated in a thin thickness of about 30 to 70 μm, and curing it at room temperature for 2 to 3 hours, the resulting physical properties can be fully exhibited.

The acrylic emulsion used in the primer as described above is one selected from the group consisting of 30 to 70 parts by weight of an acrylic acid ester-based monomer, α-methylstyrene, trans-β-methylstyrene, β-methylstyrene, and 4-methylstyrene. Process for preparing a monomer mixture comprising 10 to 50 parts by weight of at least one aromatic vinyl-based monomer, 1 to 10 parts by weight of an acrylic monomer for adhesion promotion containing fumaric acid ester or a modified methacrylamide, and 0.5 to 4 parts by weight of an organic acid-based monomer ; preparing an addition polymerization mixture by mixing 10 to 60 parts by weight of the monomer mixture, 0.2 to 5 parts by weight of a surfactant, and 0.1 to 1 parts by weight of a radical polymerization initiation catalyst; and adjusting the pH of the addition polymerization mixture to 7 to 10 using a pH adjusting agent, but the present invention is not particularly limited in the method for preparing the acrylic emulsion itself.

Here, if the amount of the aromatic vinyl-based monomer used is less than 10 parts by weight based on the total weight of all monomers, it is difficult to obtain a resin having excellent hardness, and if it exceeds 50 parts by weight, there is a risk of weakening the weather resistance. In addition, when the amount of the acrylic monomer used is less than 1 part by weight based on the total weight of all monomers, adhesion is deteriorated, and when it exceeds 10 parts by weight, sludge is generated during the reaction and is not preferable in terms of cost. In addition, an appropriate amount of an organic acid-based monomer is used in consideration of the storage stability and viscosity of the resin, and the pH is adjusted to 7 to 10 and then diluted with water corresponding to a volume ratio of 2 to 4 times to be environmentally friendly and at room temperature. It is possible to form a water-soluble primer having excellent durability and abrasion resistance with a thickness of 30 to 70 µm (dry film).

Finally, the water-based thermal barrier coating step (S40) is a process of applying a silicone acrylic emulsion-based thermal insulating paint to a thickness of 0.1 to 0.3 mm on the cured acrylic emulsion primer, and the silicone acrylic emulsion-based thermal insulating paint used in the present invention is 15 to 25% by weight of water, 40 to 50% by weight of silicone acrylic emulsion, 15 to 25% by weight of titanium dioxide, 5 to 10% by weight of limestone powder, and 5 to 10% by weight of amorphous synthetic silica gel.

The thermal barrier coating film formed as described above has an excellent solar heat reflection effect equivalent to that of oil even when 100% water-based solvent that does not use any organic solvents is used, and exhibits excellent thermal insulation effect due to low thermal conductivity. Of course, it has the effect of saving energy and increasing the durability of the structure itself by controlling the internal temperature of the building made of steel structure.

The silicone acrylic emulsion is a non-toxic material that can be used for building external wall cracks, internal wall gap filling, and internal soundproof sealing. It has fast curing properties, excellent adhesive strength, durability, and flame retardancy. and environmentally friendly. In addition, since the adhesiveness with the primer formed by the acrylic emulsion primer is good, in the present invention, a thermal barrier paint containing a silicone acrylic emulsion base material and a suitable functional inorganic additive is constituted as a water-based thermal barrier layer.

Titanium dioxide, a heat-shielding pigment added thereto, can be selectively used or mixed with anatase-type titanium dioxide (anatase TiO ₂ ) and rutile-type titanium dioxide (rutile TiO ₂ ). It is insoluble in all solvents, exhibits anisotropy with a high refractive index, and has high light scattering properties and is known as a non-toxic, insulating material that exists in a very stable state. In addition, because of its high oxidizing power, it not only suppresses the occurrence of mold or bacteria due to antibacterial action, but also removes odors and sterilizes. was found to exist.

In addition, limestone powder, which is a functional filler, is used in consideration of the insulation properties of concrete structures. In general, intermediate grade limestone is used in cement, agriculture, and other fields, and high-quality limestone with difficult properties is required in steelmaking, chemical engineering, and ceramics. , limestone is mainly used as a raw material for cement such as portland cement and lightweight concrete, as a solvent for furnaces, and as an iron-making solvent for refractory brick linings. When the limestone powder is included in an amount of less than 5% by weight based on the total weight of the thermal barrier coating, the strength, dimensional stability, abrasion resistance, etc. of the coating film may be deteriorated. have.

And silica gel is a transparent grain-shaped porous material made by treating an aqueous solution of sodium silicate with an acid and containing silicon and oxygen as the main components. It has excellent absorption effect and is non-toxic to the human body, so it is mainly used as a dehumidifier for food packaging, and is also used as an adsorbent for chromatography using organic solvents or as a carrier for catalysts.

When an acid is added to the silica gel, a silica sol having primary particles is generated, and the silanol group (Si-OH) present on the surface of the primary particle undergoes a rapid dehydration condensation reaction due to the continuous addition of acid. It is promoted to form a network of Si-O-Si to form a three-dimensional network structure. This is called 'silica gel', and then the physical properties are controlled by washing and drying processes, and finally particles with a size of several microns (㎛). It is prepared by milling with amorphous synthetic silica gel that exhibits a quenching effect.

The amorphous synthetic silica gel used in the present invention is widely known as a non-toxic, non-flammable, safe material with the same performance but a difference in its manufacturing process compared to general silica gel, and its function is restored by natural drying after absorbing moisture. Since it can be regenerated, it is possible to maintain heat shielding and heat insulation properties very effectively, so even if it contains 5 to 10% by weight based on the total weight of the heat shielding paint, its function can be sufficiently exhibited. There is a possibility that adhesion may be deteriorated due to poor properties.

The heat-shielding paint according to the present invention contains fine functional inorganic materials (titanium dioxide, limestone powder, amorphous synthetic silica gel) with an average particle size of 0.2 to 10 μm, so it is more effective than the heat insulation paint containing hollow silica with an average particle size of about 150 μm. It can form a strong coating film and has excellent durability without dropping or rupture due to thermal deformation.

In addition, when the heat shielding paint is applied to the concrete surface with a thickness of 0.1 to 0.3 mm, it has been irradiated to efficiently reflect near infrared rays (around 780 to 2500 μm wavelength), which is a heat source of sunlight, and prevents heat from flowing into the interior therefrom. Energy savings of concrete structures and other outdoor exposure equipment can be stably maintained. As a result of measuring the thermal insulation performance by requesting this to the Korea Construction Living Environment Testing Laboratory (KCL), the test results are shown in [Table 2] below.

Test Items unit Test result Test Methods Solar reflectance (300 ~ 780nm) % 96.2 JIS K 5602: 2008 Solar reflectance (780 ~ 2500nm) % 87.3 JIS K 5602: 2008 Solar reflectance (300 ~ 2500nm) % 93.5 JIS K 5602: 2008

As shown in [Table 2], the heat shielding paint used in the present invention shows a test result of a minimum of 87% and a maximum of 96% of the solar reflectance. The insulation effect is excellent due to the three-step coating construction, and in the accelerated weather resistance test [Test Method KS M 6010], the heat shielding paint according to the present invention has more than 600 hours of appearance (with or without chalking) compared to 200 hours based on the weather resistance passing standard of domestic water-based paints. showed that there was nothing wrong with

The above thermal barrier paint can form an aqueous thermal barrier coating film with a thickness of 0.1 to 0.3 mm by applying one or two times using a brush, roller, spray, etc. , high humidity (more than 85%), strong wind speed (5 m/sec), rain or snowfall, etc., can maintain good physical properties such as excellent adhesive strength and weather resistance. Depending on the weather conditions, the curing time of the heat shielding paint can be adjusted within 12 to 48 hours.

Therefore, the neutralization prevention and energy-saving coating method of the concrete structure according to the present invention is an environmentally friendly coating method that does not use any organic solvents, and is an organic-inorganic coating method based on EVA waterproofing agent containing soluble silicate and cement on the base surface of concrete. By applying a composite waterproofing agent to perform penetrative waterproofing treatment on concrete, it is possible to prevent neutralization of concrete by increasing the density of the concrete surface layer and chemically stabilizing the surface.

And by applying an acrylic emulsion primer with excellent compatibility on the organic-inorganic composite waterproofing agent, interlayer adhesion can be strengthened. Therefore, the present invention can be applied to various uses and forms within the scope of not departing from the technical spirit of the walls and flooring of concrete buildings as well as the surfaces of various steel structures.

Claims (5)

A pretreatment step (S10) of arranging the raised area of the concrete base and the deteriorated existing paint surface;
Ethylene-vinyl acetate copolymer (Ethylene-Vinyl Acetate Copolymer) 50 to 80% by weight on the base surface of the concrete, and at least one soluble silicate selected from sodium silicate, potassium silicate, and lithium silicate in a ratio of 20 to 50% by weight EVA waterproofing agent used: water: cement 1:1 to 1.5: Concrete neutralization prevention step (S20) of applying an organic/inorganic composite waterproofing agent mixed in a weight ratio of 1 to 1.5 to a thickness of 1 to 2 mm;
After the organic-inorganic composite waterproofing agent is dried, a water-soluble undercoating step of applying an acrylic emulsion primer to a thickness of 30 ~ 70㎛ (S30);
On the cured acrylic emulsion primer, 15 to 25% by weight of water, 40 to 50% by weight of silicone acrylic emulsion, 15 to 25% by weight of titanium dioxide, 5 to 10% by weight of limestone powder, 5 to 10% by weight of amorphous synthetic silica gel A water-based thermal barrier coating step (S40) of applying the composed silicone acrylic emulsion-based thermal barrier paint to a thickness of 0.1 to 0.3 mm;
A method for preventing neutralization of concrete structures and saving energy, characterized in that it comprises a. delete The method of claim 1,
The acrylic emulsion primer is applied to the surface to be coated by diluting an acrylic emulsion having a solid content of 25 to 35 wt% and water in a volume ratio of 1: 2 to 4, and curing it at room temperature for 2 to 3 hours. Energy saving coating method. delete delete

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