KR102344283B1 - Painting Construction Method For Surface Repair And Reinforcement Of Bridge Structures - Google Patents

Abstract

The present invention relates to a painting method for surface repair and reinforcement of bridge structures, which uses a room temperature-curable one-component high-durability water-soluble fluorine resin paint. More specifically, the painting method comprises: a maintenance step of installing a dust-blocking and protection film, which prevents dust scattering and blocks external dust during construction, in a place where a repair and reinforcement construction method is to be performed; a surface arrangement step of removing a paint layer with a damaged film through chemical surface treatment or mechanical treatment, cleaning the surface of a removed structure by high-pressure washing with water or wiping with a dry cloth, and cleaning the surface with an alcohol-based solvent or enamel thinner to arrange the surface; an undercoat layer forming step of forming an undercoat layer with an epoxy-based paint, wherein the undercoat layer is coated on the surface of the structure from which the existing paint is removed and coating is performed to a height corresponding to the height of the existing paint layer; an intermediate layer forming step with an epoxy-based paint; and a top coat layer forming step of forming a top coat layer with a water-soluble fluorine resin paint.

Description

Painting Construction Method For Surface Repair And Reinforcement Of Bridge Structures

The present invention relates to a painting construction method for surface repair and reinforcement of a bridge structure, and more particularly, the present invention, a painting construction method for surface repair and reinforcement of a bridge structure, prevents dust scattering and external dust generated when constructing a place where the repair and reinforcement construction method is to be performed A maintenance step of installing a dust blocking and protective film to block the; A surface cleaning step of removing the paint layer with a damaged film through chemical surface treatment or mechanical treatment and cleaning the surface of the removed structure by high-pressure washing with water or wiping with a dry cloth and then cleaning with an alcohol-based solvent or enamel thinner; forming an undercoat layer with an epoxy-based paint, wherein the undercoat layer is coated on the surface of the structure from which the existing paint has been removed, and the coating thickness is performed to a height corresponding to the height of the existing paint layer forming step; Forming an intermediate layer with an epoxy-based paint; and a topcoat layer forming step of forming a topcoat layer with a water-soluble fluororesin paint.

The coating film formed on the surface of a bridge structure made of steel or concrete is deteriorated and damaged by external air or ultraviolet rays over time, so repainting is required for repair and reinforcement.

Heavy-duty anticorrosive paints and architectural paints, which are coated or painted after removing the existing damaged paint for repair and reinforcement, form a coating film on the part exposed to the outside, so stain resistance and discoloration resistance are treated as important physical properties, double acrylic Paints and alkyd paints are easily modified by UV rays compared to acrylic urethane paints or fluorine paints, and as the painted parts look aged, it is cumbersome to repaint them after 3 to 5 years. Acrylic urethane paints and fluorine paints are mainly oil-based There is a disadvantage in that there are restrictions on the use of the paint as the regulation of volatile organic compounds (VOC) is strengthened as a paint.

In the case of double fluororesin, the carbon atom and fluorine atom of the fluoroolefin have a very strong bond with a bonding energy of 105.4 kcal/mol, so it has very strong characteristics against ultraviolet rays and air pollutants. Most fluorine paints are isocyanate Since it is a two-component oil-based paint that requires a curing agent, if a one-component fluorine paint that does not require mixing the main agent and the curing agent can be obtained in a water-based type, it is expected to be available as a high-durability paint that can respond to the regulation of volatile organic compounds. can

Republic of Korea Patent No. 10-2056839 relates to an ultra-weather-resistant eco-friendly steel coating composition containing a fluororesin and a method for protecting the surface of a steel structure using the same, and relates to an epoxy resin, a fluororesin, a functional filler, barium sulfate, dioctyl terephthalate. , a mixture of pigments, additives and diluents; By using a mixture of an amine-based curing agent including a polyamide adduct curing agent, a functional filler, dioctyl terephthalate, an additive, and a curing agent mixed with a diluent, it can be used as steel materials such as steel structures, bridges, steel bridges, deck boards, and road facility structures. In addition to preventing corrosion, corrosion, etc. of the constructed structure, it has the effect of significantly reducing the maintenance cost used for this, and can express heat resistance and durability and the function of a rust-preventing surface protection material together, as well as harmful heavy metals It is proposed to relate to an ultra-weather-resistant eco-friendly steel coating composition containing a fluororesin, which is safe and environmentally friendly to the human body because there is no elution of Including insulating oxide, nitride or carbide containing at least one selected from, a functional filler selected from a structure having a mesoporous structure is required separately, and the present functional filler is the core of the invention, and fluorine There is a problem in that there is no mention about the high curing temperature characteristic of the resin.

Registered Patent No. 10-2056839 (Title of the invention: Ultra-weather-resistant eco-friendly steel coating composition containing fluororesin and surface protection coating method for steel structures using the same)

It is an object of the present invention to provide a method for repairing and reinforcing a painting construction method for a surface of a bridge structure damaged by exposure to existing outside air or ultraviolet rays.

Another object of the present invention is to provide a construction method that prevents dust generated from the removed paint from leaking to the outside in consideration of the physical properties of the existing painted paint, as well as preventing external substances from contamination inside. .

Another object of the present invention is to prevent deterioration of the durability of the structure on the surface of steel and concrete exposed to outdoor ultraviolet rays and air pollution, respectively, have excellent crack followability on the concrete surface, and do not generate VOC (volatile organic compound) It is to provide an eco-friendly, one-component, highly durable, water-soluble fluororesin paint having the property of curing at room temperature and a paint construction method using the same.

The present invention provides a method for constructing a painting for surface repair and reinforcement of a bridge structure, comprising: a maintenance step of installing a dust blocking and protective film that prevents dust scattering and blocks external dust at a place where the construction method is to be performed; A surface cleaning step of removing the paint layer with a damaged film through chemical surface treatment or mechanical treatment and cleaning the surface of the removed structure by high-pressure washing with water or wiping with a dry cloth and then cleaning with an alcohol-based solvent or enamel thinner; forming an undercoat layer with an epoxy-based paint, wherein the undercoat layer is coated on the surface of the structure from which the existing paint has been removed, and the coating thickness is performed to a height corresponding to the height of the existing paint layer forming step; Forming an intermediate layer with an epoxy-based paint; and a top coat layer forming step of forming a top coat layer with a water-soluble fluororesin paint.

The epoxy-based paint used in the step of forming the undercoat layer and the step of forming the intermediate layer is 25 to 40 wt% of water, 20 to 30 wt% of bisphenol A diglycidyl ether, 0.01 to 5 wt% of barium sulfate, 6 to titanium dioxide 15% by weight, silicon dioxide 4 to 10% by weight, mica 3 to 7% by weight, strontium oxide 0.7 to 1.5% by weight, sodium nitrite 0.2 to 0.6% by weight.

The water-soluble fluororesin paint is

Water-soluble fluororesin 30 to 40% by weight, titanium dioxide 15 to 25% by weight, water-dispersed acrylic urethane 10 to 20% by weight, water 10 to 20% by weight, and barium sulfate 1 to 10% by weight.

The intermediate layer has a thickness of 50 to 100 μm, respectively, and the top coat layer has a thickness of 30 to 50 μm.

The present invention has the following effects.

(1) The present invention provides a method for repairing and reinforcing a painting construction method for a surface of a bridge structure damaged by exposure to existing outside air or ultraviolet rays.

(2) The present invention provides a construction method that not only prevents dust generated from the removed paint from leaking to the outside in consideration of the physical properties of the existing painted paint, but also prevents external substances from contamination to the inside.

(3) The present invention prevents deterioration of the durability of structures on the surface of steel and concrete exposed to outdoor UV rays and air pollution, respectively, has excellent crack followability on the concrete surface, and does not generate VOCs (volatile organic compounds), so it is eco-friendly However, a one-component high-durability water-soluble fluororesin paint having the property of curing at room temperature and a paint construction method using the same are provided.

1 is a schematic view showing the present invention in a time-series configuration of a painting construction method for surface repair and reinforcement of a bridge structure.

First, before entering into the detailed description of the present invention, if it is determined that the detailed description of the known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, the terms to be described later are terms defined in consideration of the functions in the present invention, which may vary depending on the intention or custom of the user or operator, so the definition is "Painting construction method for surface repair and reinforcement of bridge structures according to the present invention" It should be made based on the content throughout this specification describing ".

The terminology used herein is for the purpose of referring to specific embodiments only, and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite.

The meaning of "comprising," as used herein, specifies a particular characteristic, region, integer, step, operation, element and/or component, and other specific characteristic, region, integer, step, operation, element, component and/or It does not exclude the presence or addition of groups.

All terms including technical terms and scientific terms used in this specification have the same meaning as those commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related art literature and the presently disclosed content, and unless defined, are not interpreted in an ideal or very formal meaning.

1 is a schematic view showing the present invention in a time-series configuration of a painting construction method for surface repair and reinforcement of a bridge structure.

Referring to FIG. 1 , the present invention provides a method for repairing and reinforcing the surface of a bridge structure, comprising: a maintenance step of installing a dust blocking and protective film that prevents dust scattering and blocks external dust when constructing a place where the repair and reinforcement construction method is to be performed; A surface cleaning step of removing the paint layer with a damaged film through chemical surface treatment or mechanical treatment and cleaning the surface of the removed structure by high-pressure washing with water or wiping with a dry cloth and then cleaning with an alcohol-based solvent or enamel thinner; forming an undercoat layer with an epoxy-based paint, wherein the undercoat layer is coated on the surface of the structure from which the existing paint has been removed, and the coating thickness is performed to a height corresponding to the height of the existing paint layer forming step; Forming an intermediate layer with an epoxy-based paint; and a top coat layer forming step of forming a top coat layer with a water-soluble fluororesin paint.

The maintenance step is an operation to block the inflow of dust from places around the construction site in advance, and it protects the workers by installing a protective film such as dust and dustproof nets around the construction site, as well as removing the existing paint components chemically or mechanically. This is a step that must be performed in order to prevent it from being scattered in the form of dust and leaking to the outside.

In the surface cleaning step, the damaged existing paint layer must first be chemically or mechanically treated. The chemical treatment method is a paint remover corresponding to the physical properties of the existing paint (Patent Registration No. 10-2089913 paint remover and a paint removal method using the same, or a patent Registration No. 10-2047887 paint remover and paint removal method using the same), and the mechanical treatment method is at least one selected from the group consisting of silica sand, shot, copper reduction by-product, garnet, flint, silicon carbide, and aluminum oxide. A blast removal method using an abrasive as a medium can be implemented.

When the surface treatment is completed, the surface is cleaned by high pressure washing or wiping with a dry cloth, followed by washing with an alcohol-based solvent or enamel thinner. The main purpose is to remove mill scale, rust, old coating film, oxide, corrosion products and other foreign substances, and use a high-pressure washing machine to shoot particles made of a mixture of blast furnace slag powder pulverized into fine particles, metal powder and sand powder. By giving, it is possible to remove the above-mentioned foreign material.

The intermediate layer has a thickness of 50 to 100 μm, and the top coat layer has a thickness of 30 to 50 μm.

lower class and middle class

The epoxy-based paint forming the undercoat layer and the intermediate layer is

Water 32-40% by weight, bisphenol A diglycidyl ether 22-30% by weight, barium sulfate 0.01-5% by weight, titanium dioxide 6-15% by weight, silicon dioxide 4-10% by weight, mica 3-7% by weight , strontium oxide (Strontium Oxide) 0.7 to 1.5% by weight, sodium nitrite is characterized in that it is composed of 0.2 to 0.6% by weight.

The bisphenol A-bisphenol A diglycidyl ether polymer allows the present paint to have the characteristics of an epoxy-based paint. In particular, it has excellent affinity or adhesion to a metal surface. When it exceeds the range of 22 to 30 wt % There is a problem that the workability is remarkably deteriorated, such as poor adhesion to the metal surface or peeling.

The barium sulfate is white that forms the base of the paint, and it has excellent color toning properties with other colors, and prevents the paint from discoloring easily. It is confirmed that the use of excessive input is used even though there is no better effect in terms of the weight ratio with other substances.

Since the titanium dioxide is a very stable material, it should be evenly dispersed because it improves weather resistance and discoloration resistance to heat or light. .

The silicon dioxide is a material that has affinity with the concrete surface in particular, and when less than 4 wt% is used, the characteristic having affinity with the concrete surface is hardly expressed, and when it exceeds 10 wt%, the workability is rather deteriorated. There is a problem that the time is long.

The mica uses thin-plate muscovite, has good water permeability, electrical insulation, and fire resistance, and it is preferable to use 3 to 7 wt% of the high anticorrosive paint for heavy loads, which is added in less than 3 wt%. Penetration inhibiting power is weakened, and when it is added in excess of 7% by weight, the adhesion between the resin inside the coating film is deteriorated.

The strontium oxide (Strontium Oxide) acts as a corrosion inhibitor, and since it is not a heavy metal, it has an eco-friendly characteristic, thereby electrochemically inhibiting or preventing corrosion of metal.

The sodium nitrite significantly improves water resistance, rust prevention performance, and adhesion to the surface to be constructed, and also serves to prevent corrosion of the internal steel material even if the coating film is damaged.

As for the formation of the paint layer, since the present invention relates to the repair and reinforcement construction method of the existing paint, the thickness of the undercoat is preferably as high as the height of the existing paint, and the thickness of the intermediate layer is preferably 50 to 100 μm.

It is preferable that the application rate be about 8.5m^2 per liter, and in particular, since the thickness of the intermediate layer is thin, it is experimentally determined in consideration of this.

The coating film thus formed is densely formed with excellent adhesion, rust prevention, water resistance and chemical resistance.

Examples 1 and 2 and their comparative examples

As an epoxy paint composition based on the weight ratio as shown in Table 1 below, sprayed to a thickness of 1 mm on the surface of concrete and steel, and tested for physical properties (60% relative humidity at 20°C) after 6 hours, respectively, and the results are shown in Table 2 shown in

ingredient Example 1 Comparative Example 1 (A) Comparative Example 1 (B) Example 2 Comparative Example 2 (B) Comparative Example 2 (B) water 40 40 40 40 52 40 Bisphenol A-bisphenol A diglycidyl ether 29 31 29 30 19 32 barium sulfate 4 4 4 3 5 5 titanium dioxide 12.5 12 16 16 5 9.5 silicon dioxide 7 8.5 7.5 7.5 10 10 mica 6 3 2 2 7 2 strontium oxide One One One One 1.5 One sodium nitrite 0.5 0.5 0.5 0.5 0.5 0.5

ingredient Example 1 Comparative Example 1 (A) Comparative Example 1 (B) Example 2 Comparative Example 2 (B) Comparative Example 2 (B) Concrete (visual observation) normal partial peeling normal normal separation partial peeling Steel (visual observation) normal partial peeling normal normal separation partial peeling Concrete (film strength) strong normal weakness weakness very weak very weak Steel (film strength) strong normal weakness weakness very weak very weak Concrete (sedimentation phenomenon) none none Occur Occur none none Steel (sedimentation phenomenon) none none Occur Occur none none

As can be seen from the results of Table 2, it is out of the range of 6 to 15 wt% of titanium dioxide, or out of the range of 22 to 30 wt% of bisphenol A-bisphenol A diglycidyl ether polymer, or 3 to 7 wt% of mica In all cases, it can be seen that problems such as construction quality problems or very long curing times occur.

upper floor

The water-soluble fluororesin paint is

Water-soluble fluororesin 30 to 40% by weight, titanium dioxide 15 to 25% by weight, water-dispersed acrylic urethane 10 to 20% by weight, water 10 to 20% by weight, and barium sulfate 1 to 10% by weight.

The water-soluble fluororesin improves water resistance and fire resistance without emitting harmful substances such as VOC, and has a good thermal barrier rate and anti-pollution effect. It is preferable to use within the weight % range, and if it is less than 30 weight %, it is cured by ultraviolet rays and peeling may occur relatively quickly. If it exceeds 40 weight %, the curing time at room temperature is very long. occurs

Since titanium dioxide is a very stable material, it should be evenly dispersed because it improves weather resistance and discoloration resistance to heat or light. and no precipitation occurred.

The barium sulfate is white, which forms the base of the paint, and has excellent tonal properties with other colors, and prevents the second subject from being easily discolored.

The water-dispersed acrylic urethane should be used within the range of 10 to 20 wt % in order to improve the adhesion of the paint and excellent water resistance and rust prevention.

The top coat layer forming step is characterized in that the curing to drying time at room temperature is 6 to 7 hours when the relative humidity is 60% at 20°C.

The thickness of the top coat layer is characterized in that it is set to 30 - 50 μm.

In this case, it is preferable that the application rate be 12m^2 per 1 liter.

Examples 3 and 4 and their comparative examples

Based on the weight ratio as shown in Table 3 below, a fluororesin coating composition was sprayed to a thickness of 40 μm on the surface of a fully cured epoxy resin, and the physical properties were tested after 6 hours (20 ° C. relative humidity: 60%), respectively. The results are shown in Table 4.

ingredient Example 3 Comparative Example 3 (A) Comparative Example 3 (B) Example 4 Comparative Example 4 (B) Comparative Example 4 (B) water-soluble fluororesin 40 29 41 30 38 35 titanium dioxide 22 25 19 22 25 19 Water-dispersed acrylic urethane 10 17 15 20 9 21 water 20 20 20 20 20 20 barium sulfate 10 9 5 8 8 5

ingredient Example 3 Comparative Example 3 (A) Comparative Example 3 (B) Example 4 Comparative Example 4 (B) Comparative Example 4 (B) visual observation normal partial peeling normal normal partial peeling partial peeling curing time normal Hardening Uncured (greater than +8 hours) normal normal normal film strength very strong strong weakness strong very weak strong

As can be seen from the results of Table 4, when it is out of the range of 30 to 40 wt % of the water-soluble fluororesin or 10 to 20 wt % of the water-dispersed acrylic urethane, the coating film strength is weak or some peeling occurs from the surface, etc. It can be seen that all of them have problems with construction quality, or problems such as very long curing times.

The present invention has the following effects.

(1) The present invention provides a method for repairing and reinforcing a painting construction method for a surface of a bridge structure damaged by exposure to existing outside air or ultraviolet rays.

(2) The present invention provides a construction method that prevents dust generated from the removed paint from leaking to the outside in consideration of the physical properties of the existing painted paint, as well as preventing external substances from contamination to the inside.

(3) The present invention prevents deterioration of the durability of structures on the surface of steel and concrete exposed to outdoor UV rays and air pollution, respectively, has excellent crack followability on the concrete surface, and does not generate VOCs (volatile organic compounds), so it is eco-friendly However, a one-component high-durability water-soluble fluororesin paint having the property of curing at room temperature and a paint construction method using the same are provided.

Claims (4)

In the painting construction method for surface repair and reinforcement of a bridge structure,
How to apply the paint
A maintenance step of installing a dust blocking and protective film that prevents dust scattering and blocks external dust when constructing a place where the repair and reinforcement construction method is to be performed;
A surface cleaning step of removing the paint layer with a damaged film through chemical surface treatment or mechanical treatment and cleaning the surface of the removed structure by high-pressure washing with water or wiping with a dry cloth and then cleaning with an alcohol-based solvent or enamel thinner;
forming an undercoat layer with an epoxy-based paint, wherein the undercoat layer is coated on the surface of the structure from which the existing paint has been removed, and the coating thickness is performed to a height corresponding to the height of the existing paint layer forming step;
Forming an intermediate layer with an epoxy-based paint; and
A top coat layer forming step of forming a top coat layer with a water-soluble fluororesin paint;
The water-soluble fluororesin paint is
Water-soluble fluororesin 30 to 40% by weight, titanium dioxide 15 to 25% by weight, water-dispersed acrylic urethane 10 to 20% by weight, water 10 to 20% by weight, and barium sulfate 1 to 10% by weight. How to apply paint for surface repair and reinforcement. The method according to claim 1,
The epoxy-based paint used in the step of forming the undercoat layer and the step of forming the intermediate layer is,
Water 32-40% by weight, bisphenol A diglycidyl ether 22-30% by weight, barium sulfate 0.01-5% by weight, titanium dioxide 6-15% by weight, silicon dioxide 4-10% by weight, mica 3-7% by weight , Strontium Oxide (Strontium Oxide) 0.7 ~ 1.5% by weight, sodium nitrite 0.2 ~ 0.6% by weight of a painting construction method for reinforcing the surface of a bridge structure, characterized in that it consists of. delete The method according to claim 1,
The thickness of the intermediate layer should be 50 ~ 100 μm,
The coating construction method for surface repair and reinforcement of bridge structures, characterized in that the thickness of the top coat is 30 - 50 μm.

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