KR101054033B1 - Silicate hybrid coating material and coating method for bridge using the same - Google Patents

Abstract

PURPOSE: A silicate hybrid coating material is provided to form a physically and chemically stable film layer on the surface of a concrete bridge and to improve corrosion resistance of a steel bridge by coupling a concrete bridge and a steel bridge in one body. CONSTITUTION: A silicate hybrid coating material comprises 10~35 weight% of tetraalkoxy silicate, 16~75 weight% of acrylic copolymers, 5~15 weight% of ethyl alcohol, and 5~40 weight% of propyl methyl silicone intermediates. A method for preparing the silicate hybrid coating material comprises the steps of: injecting the tetraalkoxy silicate, ethyl alcohol and propyl methyl silicone intermediates into a reaction bath and raising and stirring the materials at 80~90 °C; and dropping the acryl monomer, 4-cyanovaleric acid, and glycidalmethacrylate.

Description

Silicate Hybrid Coating Material, Manufacturing Method thereof, and Bridge Coating Method Using The Same {SILICATE HYBRID COATING MATERIAL AND COATING METHOD FOR BRIDGE USING THE SAME}

TECHNICAL FIELD The present invention relates to the field of construction materials, and in particular, to a coating material used for surface coating of bridges.

As a material used to shield concrete bridges and steel bridges from deterioration damage factors, it is most preferable to use materials that can be integrated with existing concrete and steel bridges.

In addition, the surface temperature of concrete bridges and steel bridges is often 60 ° C or higher when exposed to direct sunlight in summer, so the thermal expansion coefficient (about 11 strains, 11 × 10 ^-6 change per 1 ° C) of existing concrete and steel bridges is possible. There is a need for a coating material capable of integrating behavior as a near material.

Conventional organic epoxy or acrylic resins show great adhesive strength at first, but the shrinkage and expansion rate due to temperature change are very different from concrete and steel, and they adhere only to the surface of concrete and steel. Falls out at the interface between concrete and steel.

In addition, coating materials based on aqueous acrylic series, SBR latex series, polyurethane series, etc. can be worked under some wet conditions and have bonding properties with cement. The barrier properties, water resistance, weather resistance, adhesion, and mechanical properties (tensile and tear strength) of coatings themselves have been limited, and they have been restricted in use. Organic coatings have been mainly used in areas requiring deterioration environments or durability.

However, many studies have been conducted on the development of an environmentally friendly inorganic binder coating agent without the release of heavy metals or volatile organic compounds, along with the global environmental protection trend. The coating agent deteriorates due to various environmental factors after release and curing, in particular, acid rain, nitrogen oxides caused by automobile exhaust gas, sulfur oxides and chlorine ions in marine environment, and the service life due to yellowing, cracking and swelling caused by ultraviolet rays. This situation is rapidly falling and difficult to secure durability.

In addition, the conventional organic coating film is a solvent type, most of them are fluid type due to the characteristics of the solvent has a severe adverse effect on the human body during pollution problems and construction, the use of these is limited in recent years, the organic binder and inorganic concrete or steel Due to its different characteristics, it had material limitations that could not be expected to be durable due to adhesion and adhesion.

The present invention is derived to solve the above problems, by combining and acting integrally with the concrete bridge and steel bridge, to form a physical and chemically stable coating layer on the surface of the concrete bridge, to improve the corrosion resistance of the steel bridge It is an object of the present invention to present a silicate hybrid coating material, a method of manufacturing the same, and a silicate hybrid coating material using the same.

In order to solve the above problems, the present invention is 10 to 35% by weight of tetraalkoxy silicate (ES), 16 to 75% by weight of acrylic copolymer (ACP), 5 to 15% by weight of ethyl alcohol and propylmethylsilicon intermediate (PMSI) The present invention provides a silicate hybrid coating material comprising 5 to 40% by weight.

20-30% by weight of the tetraalkoxy silicate (ES), 36-52% by weight of the acrylic copolymer (ACP), 5-10% by weight of the ethyl alcohol, 10-30% by weight of the propylmethylsilicone intermediate (PMSI) It is preferable to include.

The acrylic copolymer (ACP) is formed by polymerization of an acrylic monomer, 4-cyanovaleric acid, and glycidal methacrylate (GMA), and the silicate hybrid coating material is the tetraalkoxy silicate (ES). 10 to 35% by weight, 5 to 15% by weight of the ethyl alcohol, 5 to 40% by weight of the propylmethylsilicon intermediate (PMSI), 10 to 50% by weight of the acrylic monomer, the 4-cyanobaric acid (4 -cyanovaleric acid) 1 to 5% by weight, preferably containing 5 to 20% by weight of the glycidal methacrylate (GMA).
The silicate hybrid coating material is 10 to 35% by weight of the tetraalkoxy silicate (ES), 5 to 15% by weight of the ethyl alcohol, 5 to 40% by weight of the propylmethylsilicon intermediate (PMSI), 30 to 40% by weight of the acrylic monomer %, 1 to 2% by weight of the 4-cyanobaric acid, preferably 5 to 10% by weight of the glycidal methacrylate (GMA).

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The acrylic monomer is preferably formed by one or two or more of butyl acrylate (BAM), methyl methacrylate (MMA), glycidal methacrylate (GMA).

The present invention is a method for producing the silicate hybrid coating material, the tetraalkoxy silicate (ES), the ethyl alcohol, the propylmethylsilicon intermediate (PropylMethylSilicone Intermediate) is added to the reaction tank, the temperature is raised to 80 ~ 90 ℃ while stirring step; A polymerization step of dropping the acrylic monomer, the 4-cyanovaleric acid, and the glycidal methacrylate (GMA); a method of manufacturing a silicate hybrid coating material comprising a Present together.

The temperature increase in the temperature increase step is preferably 90 ~ 130 ° C / h.

It is preferable that the temperature increase temperature of the said temperature raising step is 100-120 degreeC / h.

The stirring speed of the temperature increase step is preferably 30 ~ 100rpm.

The stirring speed of the temperature increase step is preferably 50 ~ 70rpm.

The polymerization step is preferably made for 3 to 4 hours.

After the polymerization step, it is preferable to further include the step of cooling after aging to maintain 90 ℃ 2 ~ 3 hours.

The present invention silicate hybrid coating material; 10-30% by weight of ceramic powder; Inorganic filler 20 ~ 60% by weight; The silicate hybrid coating, characterized in that it comprises together.

The silicate hybrid coating material; 20-40% by weight of ceramic powder; Inorganic filler 30 to 50% by weight; It is preferable to include.

The ceramic powder is preferably formed by mixing one or two or more of Al ₂ O ₃ , ZnO, TiO ₂ .

The inorganic filler is preferably heavy calcium carbonate (CaCO ₃ ) or hard calcium carbonate (CaCO ₃ ).

The present invention together with the coating method of the bridge characterized by applying the silicate hybrid coating on the surface of the bridge.

In accordance with an embodiment of the present invention, a silicate hybrid coating material, a method of manufacturing the same, and a method of forming a coating layer physically and chemically stable on the surface of a concrete bridge and improving the corrosion resistance of the steel bridge by combining and behaving integrally with a concrete bridge and a steel bridge. The silicate hybrid coating used is presented.

Hereinafter, embodiments of the present invention will be described in detail.

Until recently, methods of coating or infiltrating concrete surfaces with organic or inorganic materials have been used to suppress degradation of concrete bridges and improve waterproof performance.

Coating waterproof materials that have a waterproofing effect by coating a conventional organic polymer such as silicone, epoxy, urethane, etc. on the surface have problems such as breaking or peeling of the coating due to vibration, water vapor pressure, elastic modulus with concrete, etc. It has a fundamental limitation because it is not integrated with concrete, which is an inorganic material, but it is used as a coating material because there is no realistic alternative.

Accordingly, the present invention forms an effective coating layer by reaction with calcium hydroxide, a hydrate having a representative OH group in concrete, when applied to concrete bridges by using a silicate having a bonding mechanism based on the sol-gel process as a base material.

The sol-gel reaction of the silicate compound introduced in the present invention has had a considerable effect in the IT field (semiconductor, aviation, automobile, etc.) over the past several years, and the chemical reaction mechanism is a silicon or metal alkoxide unit precursor (monomer). precursors) to create various types of inorganic networks.

The sol-gel reaction method of silicate compounds applied in the IT field was first discovered in the late 1800's and actively studied since the 1930's. However, in the 1970's, a single inorganic gel was used to form a strong silicate bond at low temperature without melting at high temperatures. Being able to induce new interest.

Unlike the traditional method of making inorganic binders by melting at high temperatures, this process enables the production of homogeneous inorganic oxides with good properties such as hardness, chemical stability, controlled pores and thermal conductivity at room temperature.

The technique used in semiconductors in the IT field is a method of applying a sol-gel process to form various shapes in a gel state to obtain a single monolith, a thin film, a fiber, a single size powder, and the like. It can be used to make optical materials, protective films and porous films, optical coatings, window insulators, dielectric and electronic material coatings, high temperature superconductors, reinforcing fibers, fillers, and catalysts.

Therefore, the present invention was to develop a silicate compound by combining this sol-gel process with concrete to improve the strength of the concrete and durability of the structure.

The sol-gel process that occurs in the silicate compound, as its name implies, creates a colloidal suspension (sol: sol) in the presence of the silicate compound in contact with the concrete surface. Refers to the process of making inorganic connective tissue that binds to concrete hydrates.

Here, the precursor of the silicate necessary to form the sol state, that is, the colloidal state, is composed of a material in which metal or metalloid elements are surrounded by various reactive ligands, and metal alkoxides are most used. This is because these substances react easily with water.

The most widely used metal alkoxide is an alkoxysilane. In the present invention, the synthesis was based on tetraalkoxy silicates having four functional groups.

The silicate hybrid coating agent of the present invention is to improve the durability of the concrete bridge by applying to the concrete surface using a spray gun or a brush, etc., the coating agent of the present invention is a silicate containing an ethoxy (ethoxy) functional group It is composed of inorganic material and high molecular material containing such functional group.

Silicate materials containing ethoxy or methoxy functional groups react with calcium hydroxide present in concrete to react with a gel-like substance with an alcohol content.

Similarly, polymers containing ethoxy functional groups also undergo crosslinking reactions, leading to polymer gelation. Eventually, such a composition will naturally react with calcium hydroxide as an organic and inorganic complex on the concrete surface.

In the case of steel bridges, the material is made of steel, and the functions to be provided as surface-treated paints are corrosion resistance to the material and adhesion to the top coat.

Corrosion of the metal proceeds electrochemically.

In the neutral region of the steel anode reaction ^{(Fe ⇒ Fe 2 + + 2e} -) and the cathode reaction _{(1 / 2O 2 + H 2} O + 2e - ⇒ 2OH -) is an Fe (OH) proceeds constant velocity, corrosion products ₂ This reaction occurs in which acid and alkali ions become accelerators.

Therefore, in order to prevent corrosion of the metal, it is necessary to block the corrosion factors such as water, oxygen, and electrolyte ions.

For this purpose, the firm adhesion between the metal material and the surface treatment film, the water resistance, water permeability, oxygen permeability, ion permeability, electrical insulation, chemical resistance, mechanical properties (elasticity, glass transition temperature, stress relaxation) of the coating film are important. .

From this point of view, a high affinity paint with a steel material capable of forming a chemical conversion coating is required for the inactivation of the metal surface, and a barrier coating (permeation blocking of electrolyte ions) can be formed to prevent corrosion reaction factors. A dense coating is needed.

In addition, in order to impart the coating property of the coating agent, a polymer-based skeleton having polarity and stress relaxation ability of the coating film surface is required.

Therefore, the polymer material containing the ethoxy functional group of the silicate hybrid technique applied in the present invention smoothly performs its function as a coating material of steel.

Hereinafter, the coating material to which the silicate hybrid technique according to the present invention is applied will be described in detail.

Basically, the silicate hybrid coating material according to the present invention is 10 to 35% by weight of tetraalkoxy silicate (ES), 16 to 75% by weight of acrylic copolymer (ACP), 5 to 15% by weight of ethyl alcohol, and propylmethylsilicone intermediate ( PMSI) 5 to 40% by weight.

Wherein tetraalkoxy silicate is comprised by the general formula as Si (OR) _4, or _{(RO) 3 Si [OSi (} OR) 2 OR], where R may have at least four functional groups as the C1 ^-6 alkyl group, couple It is a substance which has a ring function and is easily condensed by hydrolysis in the presence of a catalyst and produces a colloidal sol.

The manufacturing method of the silicate hybrid coating material according to the present invention is as follows.

First, 10 to 35% by weight of tetraalkoxy silicate (ES) (more preferably 20 to 30% by weight), 5 to 15% by weight of ethyl alcohol (more preferably 5 to 10% by weight) and propyl in the reaction tank After adding 5-40 weight% (more preferably, 10-20 weight%) of methyl silicone intermediate (PropylMethylSilicone Intermediate), it is stirred, heating up slowly to 80-90.

At this time, the elevated temperature is 90 ~ 130 / h (more preferably 100 ~ 120 / h) and the stirring speed is 30 ~ 100rpm (more preferably 50 ~ 70rpm).

Next, after checking the reflux state in the stirrer, dropping the acrylic monomer, 4-cyanovaleric acid, glycidal methacrylate (GMA) prepared to form an acrylic copolymer (ACP) ( Dropping) to polymerize.

The acrylic copolymer (ACP) in the total coating material (100% by weight) is 16 to 75% by weight, which is specifically 10 to 50% by weight of the acrylic monomer (more preferably 30 to 40% by weight), 4-cyanobar 1 to 5% by weight of 4-cyanovaleric acid (more preferably 1 to 2% by weight), 5 to 20% by weight of glycidal methacrylate (GMA) (more preferably 5 to 10% by weight) It is comprised by superposition | polymerization (remaining component and compounding ratio of the whole coating material (100 weight%) are the above-mentioned (10-35 weight% of tetraalkoxy silicates (ES), 5-15 weight% of ethyl alcohol, and propylmethyl silicone intermediate ( PMSI) 5 to 40% by weight).

Dropping is controlled at a rate of continuous dropping of the acrylic monomer, and the dropping acrylic monomer is one or more of butyl acrylate (BAM), methyl methacrylate (MMA), and glycidal methacrylate (GMA). Is formed by.
Acrylic monomers were used by BASF Corporation, glycidal methacrylate and 4-cyanobaric acid were used by Sigma-aldrich Corporation, and propylmethylsilicone interimator was Z-6018, DOW CORNING Corporation.

After dropping for about 3 ~ 4 hours, it is maintained at 90 ℃ for 2 ~ 3 hours and then cooled and a colorless transparent viscous liquid can be obtained.

This viscous liquid is a complex formed by the reaction of carboxyl groups in the acrylic copolymer with the ethoxy group in the tetraalkoxy silicate, the combination of the propylmethyl silicone interimator containing the cyranol group with the acid of cyanobaric acid, and the acrylic copolymer It is composed of hydrogen bond formation of the hydroxyl group denatured in the weight hydroxyl group and ethyl silicate.

10 to 30% by weight of ceramic powder (more preferably 20 to 40% by weight) and 20 to 60% by weight of inorganic filler (more preferably 30 to 30) in order to improve adhesion performance and durability of the coating material to the colorless transparent viscous liquid thus prepared. 50 weight percent) may be used to make silicone hybrid coatings.

Here, the ceramic powder was used as a mixture of Al ₂ O ₃ and ZnO, TiO ₂ or a mixture of two or more of Rischem, and heavy calcium carbonate (CaCO ₃ ) or hard calcium carbonate (CaCO ₃ ) of Omiya Corporation was used as the inorganic filler. .

The silicate hybrid coating agent prepared as described above may coat the bridge by applying a spray or brush to the surface of the concrete bridge or steel bridge two to three times.

Hereinafter, the physical properties of the silicate hybrid coating material according to the present invention will be described through examples.

Hereinafter, ET refers to ethyl alcohol, ES refers to tetra-alkoxysilicate, and PMSI refers to propylmethylpropyl silicone silicone intermediate, respectively.

Experimental method according to each embodiment is as follows.

1) Status in the container

The state in the container was visually observed for the occurrence and abnormality of lumps in the container according to Test Method 2011 of KS M 5000.

2) Coating workability

The coating workability test was visually observed for abnormality after spraying and applying homogeneously using a machine to be sprayed at high temperature and high pressure according to the test method 2421 of KS M 5000.

3) Touch drying time

The dry touch time test measured whether the material of the example carried out in the coating workability test of 2) was kept in the dry touch state within 20 to 30 seconds.

4) Appearance

The appearance test was visually observed whether phenomena such as wrinkles, sag, cracks, dents, hardening, agglomeration, etc. of the applied examples occurred.

Example

In this embodiment, in order to check how the addition of PMSI affects the physical properties of the coating film, the amount of MMA is synthesized with the same amount of PMMA each time the amount of PMSI is increased, and then the hardness (GARD) and the gloss (GROSS) of the dry coating film are compared. I saw it.

As a result of the comparison, as the amount of PMSI increased, both hardness and gloss increased and the viscosity of the test specimen increased.

Considering the viscosity of the test article, the synthesis ratio of Example 2 is considered to be the best.

The physical properties of the silicate hybrid coating material were compared using the formulation shown in Table 1 below. This example analyzes the characteristics of the PMSI addition amount.

Example  One

In Example 1, the Tg value of acrylic was 56 ° C. and the content of PMSI was synthesized using only 10% by weight of the total weight.

The state of the prepared product is a transparent liquid viscous liquid state and the film of the prepared test article was applied to a thickness of 200㎛ and dried.

Gloss and hardness slip was well evaluated in the dry state of the coating film, but showed a problem in the continuity of the coating film after drying due to the high Tg value.

The viscosity of the test article was measured at 3000 cps at 20 rpm of brookfild RVT No. 4, and was applicable to the preparation of the paint.

Example  2

In Example 2, the Tg value of acrylic was 45 ° C. and the content of PMSI was synthesized using only 20% by weight of the total weight.

The state of the prepared product is a transparent liquid viscous liquid state and the film of the prepared test article was applied to a thickness of 200㎛ and dried.

The dry state of the coating film evaluated well both glossiness and hardness slipperiness | lubricacy.

The viscosity of the test article was measured at 7000 cps at 20 rpm of brookfild RVT No. 4, and was applicable to the preparation of the paint.

Example  3

In Example 3, the Tg value of acryl was set at 30 ° C. and the content of PMSI was synthesized using only 30 wt% of the total weight.

The state of the prepared product is a transparent liquid viscous liquid state and the film of the prepared test article was applied to a thickness of 200㎛ and dried.

The dry state of the coating film evaluated well both glossiness and hardness slipperiness | lubricacy.

The viscosity of the test article was measured at 13000 cps at 20 rpm of brookfild RVT No. 5, which was high for application in preparing the paint.

Increasing the content of PMSI as in the results of Examples 1, 2, and 3 increased hardness, gloss, slip, and increased the content of PMSI to change the Tg value of acrylic.

Tg value of acryl was evaluated to be the best in the physical properties of the coating film between 35-45.

Example  Review

1) Paint formulation

Silicon hybrid resin (SPH), silicon oxide (SiO ₂ ), zirconium oxide, zirconium oxide, zinc oxide (Oxidation Zinc), calcium carbonate (Calcium Carbonate) and titanium oxide (TiO ₂ ) are added to SPH and mixed under rapid stirring. Found that it should be done. At this time, since a considerable amount of heat is generated in the stirring vessel, cooling in the stirring vessel is essential.

2) Physical Properties of Silicate Hybrid Coating

As a result of analyzing the viscoelasticity of the coating film as a means of grasping the internal structure based on the molecular motion of the coating film, such as intermolecular interaction between the inorganic component and the fine particles and the organic polymer, intramolecular crosslinking state, the coating film formation is determined by the glass transition temperature ( Based on Tg), it was found to affect the corrosion resistance, workability, adhesion, and the like of the coated plate.

3) Gas Permeability of Silicate Hybrid Coating

In the anticorrosive action of the metal material by the coating film, oxygen (O ₂ ) and water (H ₂ O) that penetrate the coating film are factors.

Since these substances reach the metal material through the pore diameter of the coating film, the mechanical properties (viscoelasticity, crosslinking density), surface properties (affinity, adsorptivity), composition (polar group), etc. of the coating film are considered to be related.

In the present study based on the examples, the acrylic resin, silicate and propylmethylsilicone intermediate synthesis concentration and the degree of crosslinking in the coating film are very important factors in the relationship between oxygen permeability and water vapor permeability of the coating film, and acrylic-silicate which is a general organic-inorganic composite. It was found that the synthetic resin synthesized by using SMSI in combination with the alkyd silicone paint product using the application resin and the silicone resin has an excellent effect on improving adhesion and corrosion resistance to the metal material.

Since the above has been described only with respect to some of the preferred embodiments that can be implemented by the present invention, the scope of the present invention, as is well known, should not be construed as limited to the above embodiments, the present invention described above It will be said that both the technical idea and the technical idea which together with the base are included in the scope of the present invention.

Claims (17)

10 to 35% by weight of tetraalkoxy silicate (ES), 16 to 75% by weight of acrylic copolymer (ACP), 5 to 15% by weight of ethyl alcohol and 5 to 40% by weight of propylmethylsilicon intermediate (PMSI) Silicate hybrid coating material. The method of claim 1,
20-30% by weight of the tetraalkoxy silicate (ES), 36-52% by weight of the acrylic copolymer (ACP), 5-10% by weight of the ethyl alcohol, 10-30% by weight of the propylmethylsilicone intermediate (PMSI) Silicate hybrid coating material comprising a. The method of claim 1,
The acrylic copolymer (ACP) is formed by the polymerization of an acrylic monomer, 4-cyanovaleric acid, glycidal methacrylate (GMA),
The silicate hybrid coating material
10 to 35% by weight of the tetraalkoxy silicate (ES), 5 to 15% by weight of the ethyl alcohol, 5 to 40% by weight of the propylmethylsilicon intermediate (PMSI), 10 to 50% by weight of the acrylic monomer, 4- A silicate hybrid coating material comprising 1 to 5% by weight of cyanobaric acid (4-cyanovaleric acid) and 5 to 20% by weight of the glycidal methacrylate (GMA). The method of claim 3,
The silicate hybrid coating material
10 to 35% by weight of the tetraalkoxy silicate (ES), 5 to 15% by weight of the ethyl alcohol, 5 to 40% by weight of the propylmethylsilicon intermediate (PMSI), 30 to 40% by weight of the acrylic monomer, 4- A silicate hybrid coating material comprising 1 to 2% by weight of cyanobaric acid and 5 to 10% by weight of the glycidal methacrylate (GMA). The method of claim 3,
The acrylic monomer is a silicate hybrid coating material, characterized in that formed by mixing one or two or more of butyl acrylate (BAM), methyl methacrylate (MMA), glycidal methacrylate (GMA). As a manufacturing method of the silicate hybrid coating material of any one of Claims 3-5,
A temperature raising step of adding the tetraalkoxy silicate (ES), the ethyl alcohol, and the propylmethylsilicon intermediate to a reaction tank and stirring the temperature while heating to 80 to 90 ° C;
A polymerization step of dropping the acrylic monomer, the 4-cyanovaleric acid, and the glycidal methacrylate (GMA);
Method for producing a silicate hybrid coating material comprising a. The method of claim 6,
Method for producing a silicate hybrid coating material, characterized in that the temperature rising step of the temperature rising step is 90 ~ 130 ℃ / h. The method of claim 7, wherein
Method for producing a silicate hybrid coating material, characterized in that the temperature rising step of the temperature rising step is 100 ~ 120 ℃ / h. The method of claim 6,
The stirring speed of the temperature rising step is a method for producing a silicate hybrid coating material, characterized in that 30 ~ 100rpm. 10. The method of claim 9,
The stirring speed of the temperature rising step is a method for producing a silicate hybrid coating material, characterized in that 50 ~ 70rpm. The method of claim 6,
The polymerization step is a method for producing a silicate hybrid coating material, characterized in that made for 3 to 4 hours. The method of claim 6,
After the polymerization step,
Method for producing a silicate hybrid coating material, characterized in that it further comprises the step of cooling after aging while maintaining 90 ℃ for 2 to 3 hours. A silicate hybrid coating material according to any one of claims 1 to 5;
10-30% by weight of ceramic powder;
Inorganic filler 20-60% by weight;
Silicate hybrid coating agent comprising a. The method of claim 13,
The silicate hybrid coating material;
20-40% by weight of ceramic powder;
Inorganic filler 30-50% by weight;
Silicate hybrid coating agent comprising a. The method of claim 13,
The ceramic powder is a silicate hybrid coating, characterized in that formed by mixing one or two or more of Al ₂ O ₃ , ZnO, TiO ₂ . The method of claim 13,
The inorganic filler is a silicate hybrid coating, characterized in that the heavy calcium carbonate (CaCO ₃ ) or hard calcium carbonate (CaCO ₃ ). The coating method of the bridge characterized by apply | coating the silicate hybrid coating agent of Claim 13 to the surface of a bridge.