Durable composite anti-corrosion coating for concrete structure of road in cold region and preparation method of durable composite anti-corrosion coating

Abstract

A durable composite anticorrosive coating for a concrete structure of a road in a cold region belongs to the technical field of building materials, and adopts the specific scheme that the composite anticorrosive coating comprises an inner coating and an outer coating, the inner coating is coated on a concrete base surface, the outer coating is coated on the inner coating, and the outer coating is coated on the outer coating. The inner coating is a single-component epoxy resin interface bonding layer, and the outer coating is a single-component MMA resin sand-containing anti-corrosion layer. Through the composite structure design of the epoxy resin interface bonding layer and the MMA resin sand-containing anti-corrosion layer, the advantages of high permeability and strong bonding characteristics of epoxy resin and the advantages of rapid curing, high wear resistance, wide temperature range (still keeping toughness at-40 DEG C) and good weather resistance of MMA resin are fully played, and the efficient and lasting protection effect is achieved.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a composite anti-corrosion coating system and its preparation method for concrete road structures in cold regions, particularly highway pavement ancillary works (such as hard shoulders). Background Technology

[0002] Concrete road structures in cold northern regions have long faced severe challenges from the combined effects of multiple factors, including low temperatures, freeze-thaw cycles, de-icing salt corrosion, and ultraviolet radiation. Existing anti-corrosion coatings generally have the following problems: 1) A single coating cannot simultaneously meet the comprehensive requirements of high adhesion, freeze-thaw resistance, salt corrosion resistance, and weather resistance; 2) The interface between the coating and the concrete substrate is prone to becoming a weak point under freeze-thaw cycles, leading to adhesion failure and peeling; 3) Many coatings lack flexibility at low temperatures and are prone to embrittlement and cracking.

[0003] Although some studies have used epoxy resin or polyurea as coating materials, epoxy resin has poor weather resistance, while polyurea is expensive and requires extremely high-quality interface treatment. Therefore, developing a composite coating system that combines excellent interfacial adhesion, superior resistance to environmental aging, good construction adaptability, and reasonable cost is of great significance for ensuring the durability of concrete structures in cold regions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a composite anti-corrosion coating for road concrete with strong adhesion, excellent freeze-thaw resistance and salt corrosion resistance, suitable for harsh environments in cold regions, and its preparation method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A durable composite anti-corrosion coating for concrete structures in cold regions is disclosed. The composite anti-corrosion coating includes an inner coating and an outer coating. The inner coating is applied to the concrete substrate, and the outer coating is applied on the inner coating. The inner coating is a single-component epoxy resin interface bonding layer, forming a high-penetration and strong-adhesion transition layer. The outer coating is a single-component MMA resin sand-containing anti-corrosion layer, forming a dense, wear-resistant, and impact-resistant surface protective layer.

[0006] Furthermore, the coating density (i.e., dosage) of the single-component epoxy resin interfacial adhesive layer is 0.18-0.22 kg / m³. 2 0.2kg / m 2 The coating density of the single-component MMA resin sand-containing anti-corrosion layer is 2.8-3.2 kg / m³. 2 3kg / m 2 .

[0007] Furthermore, the single-component MMA resin sand-containing anti-corrosion layer comprises methyl methacrylate resin and hard aggregate, wherein the mass ratio of methyl methacrylate resin to hard aggregate ranges from 3:7 to 5:5, and can be appropriately adjusted according to anti-slip or wear-resistant requirements.

[0008] Furthermore, the particle size distribution of the hard aggregate is a mixture of 40-70 mesh and 70-140 mesh, with the ratio between the two being in the range of 6:4-7:3.

[0009] Furthermore, the hard aggregate includes one or more combinations of quartz sand, corundum, and basalt sand.

[0010] A method for preparing a durable composite anti-corrosion coating for concrete structures in cold-region roads includes the following steps: Step 1: Clean the concrete surface; use a blower and wire brush to thoroughly remove dust, debris and loose particles from the concrete surface to ensure that the base surface meets the technical requirements of being clean, dry, firm and free of oil stains.

[0011] Step 2: According to the designed dosage, use roller coating or spraying to evenly apply the uniformly mixed single-component epoxy resin interface adhesive to the concrete surface to form a single-component epoxy resin interface adhesive layer. Step 3: After the single-component epoxy resin interface bonding layer dries (about 20 minutes), apply the well-stirred single-component MMA resin sand-containing coating evenly to the surface of the single-component epoxy resin interface bonding layer according to the designed dosage to form a single-component MMA resin sand-containing anti-corrosion layer; the single-component MMA resin sand-containing coating needs to be thoroughly stirred before application to ensure that the anti-slip sand is evenly distributed and there is no false sedimentation.

[0012] After the surface of the single-component epoxy resin interfacial adhesive layer is dry, the single-component MMA resin sand-containing coating is applied by scraping with a notched trowel or by spraying with specialized equipment. Application should be completed in one continuous stroke to avoid repeated operations that could lead to material skinning or increased viscosity.

[0013] When applying the coating, it is important to control the uniformity of the coating thickness, especially in uneven areas of the road surface, and ensure that the overlaps are smooth.

[0014] Step 4: After construction is completed, allow it to cure under natural conditions for 5-7 days for better performance. Once the coating is completely dry, it can be put into use.

[0015] Furthermore, the relative humidity of the construction environment should not exceed 85%, and the ambient temperature should be above 5℃.

[0016] Compared with the prior art, the beneficial effects of the present invention are: Synergistic protection with superior performance: This invention, through the composite structure design of "epoxy resin interface bonding layer + MMA resin sand-containing anti-corrosion layer", fully leverages the high penetration and strong adhesion characteristics of epoxy resin and the advantages of MMA resin such as rapid curing, high wear resistance, wide temperature range (maintaining toughness even at -40℃) and good weather resistance, to achieve a highly efficient and long-lasting protective effect.

[0017] Excellent interface durability: The epoxy resin interface agent can effectively penetrate into the capillary pores of concrete to form "mechanical anchoring" and chemical bonding. The initial adhesion can reach more than 6.0 MPa, far exceeding the standard requirements (≥1.5 MPa), and it can still maintain effective adhesion after freeze-thaw and salt corrosion.

[0018] Excellent resistance to environmental corrosion: The dense cross-linked MMA resin sand-containing coating on the surface effectively blocks the intrusion of chloride ions, moisture, and ultraviolet rays. Tests have verified that the system exhibits no powdering or peeling after 28 salt-freezing cycles (3% NaCl solution, -30℃ to 20℃); its chemical resistance (acids, alkalis, salts) and artificial weathering resistance (1000h) both meet stringent requirements.

[0019] Convenient construction and moderate cost: This system features mature construction technology, requires no special or expensive equipment, can be applied at lower temperatures, and has a relatively short curing period. Compared to systems such as pure polyurea, it offers superior cost-effectiveness and is highly suitable for large-scale highway engineering applications. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Example 1: The composite coating system provided by this invention was applied in the hardened concrete protection project of the earth shoulder of a highway reconstruction and expansion project in a cold region.

[0022] Surface preparation: The surface of the newly built concrete hard shoulder is cleaned and blown to remove loose dust and debris.

[0023] Apply the interface agent: Use a roller to apply the evenly mixed one-component epoxy resin interface adhesive (0.2 kg / m²). 2 Apply evenly to the concrete surface.

[0024] Topcoat application: After the single-component epoxy resin interface adhesive has dried to the surface, use a trowel to apply the gray single-component MMA resin sand-containing coating (dosage 3.0 kg / m²) to the epoxy resin interface adhesive layer, controlling the thickness to be uniform.

[0025] Curing: Allow to cure naturally for 7 days after application. The finished coating has a uniform granular texture and adheres firmly to the substrate.

[0026] On-site inspection and follow-up showed that the coating system achieved an adhesion of 6.5 MPa. After two winters, the surface remained intact without cracking or peeling, demonstrating excellent durability.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A durable composite anti-corrosion coating for concrete structures in cold-region roads, characterized in that: The composite anti-corrosion coating includes an inner coating and an outer coating. The inner coating is applied to the concrete substrate, and the outer coating is applied on the inner coating. The inner coating is a single-component epoxy resin interface bonding layer, and the outer coating is a single-component MMA resin sand-containing anti-corrosion layer.

2. The durable composite anti-corrosion coating for concrete structures in cold-region roads according to claim 1, characterized in that: The coating density of the epoxy resin interface adhesive layer is 0.18-0.22 kg / m³. 2 The coating density of the single-component MMA resin sand-containing anti-corrosion layer is 2.8-3.2 kg / m³. 2 .

3. The durable composite anti-corrosion coating for concrete structures in cold-region roads according to claim 1, characterized in that: The single-component MMA resin sand-containing anti-corrosion layer comprises methyl methacrylate resin and hard aggregate, wherein the mass ratio of methyl methacrylate resin to hard aggregate ranges from 3:7 to 5:

5.

4. A durable composite anti-corrosion coating for concrete structures in cold-region roads according to claim 3, characterized in that: The particle size distribution of the hard aggregate is a mixture of 40-70 mesh and 70-140 mesh, with a ratio of 6:4 to 7:

3.

5. A durable composite anti-corrosion coating for concrete structures in cold-region roads according to claim 3, characterized in that: The hard aggregate includes one or more of the following: quartz sand, corundum, and basalt sand.

6. A method for preparing a durable composite anti-corrosion coating for concrete structures in cold-region roads as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Clean and dry the concrete substrate. Step 2: Apply a single-component epoxy resin interface adhesive evenly to the surface of the concrete to form a single-component epoxy resin interface adhesive layer. Step 3: After the single-component epoxy resin interfacial bonding layer dries, uniformly apply a well-stirred single-component MMA resin sand-containing coating to the surface of the single-component epoxy resin interfacial bonding layer to form a single-component MMA resin sand-containing anti-corrosion layer. Step 4: After construction is completed, allow the material to cure naturally.

7. The preparation method according to claim 6, characterized in that: In step one, clean the dust, debris, and loose particles from the concrete surface.

8. The preparation method according to claim 6, characterized in that: The relative humidity of the construction environment should not exceed 85%, and the ambient temperature should be above 5℃.

9. The preparation method according to claim 6, characterized in that: In step four, the maintenance period is 5-7 days.