A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas and its preparation method

Abstract

This invention belongs to the field of concrete material corrosion protection technology, and discloses a concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas and its preparation method. The raw materials include a primer and a topcoat, in parts by weight: the primer comprises 10-14 parts sodium methylsiloxane, 2 parts dispersant, and 86-90 parts water; the topcoat comprises 100 parts silicate cement, 1 part nano-silica, 3 parts microencapsulated material, 38 parts water, 3 parts water-reducing agent, and 0.5-1.5 parts fluorinated organosilicon compound. The composite coating design of this invention fully considers the compatibility and synergistic effect between layers, as well as adaptability to the external environment. By combining materials with different properties, it can effectively resist the erosion of saline soil, prevent the mortar layer on the concrete base surface from peeling off and delaminating, thereby ensuring the stable operation and safe and reliable operation of the power system.

Description

Technical Field

[0001] This invention belongs to the field of concrete material corrosion protection technology, specifically relating to a concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas and its preparation method. Background Technology

[0002] In some regions, saline soil is widely distributed, characterized by low rainfall and high evaporation. The soil moisture evaporates easily, leading to the concentration and accumulation of salts on or near the surface, resulting in salinization. In power systems, substations serve as critical hubs, and their stability and safety are paramount. However, saline soil environments pose a significant threat to the concrete structures of substations. Soluble salts in saline soil not only cause surface spalling and cracking of concrete but also penetrate deep into the concrete, damaging its original mechanical properties and durability, thus weakening its function as a load-bearing and protective structure. In such environments, the safety and durability of buildings and structures face enormous challenges. To ensure structural stability, in addition to selecting materials with good resistance to saline soil erosion during the design phase, effective protective measures must be taken for the concrete structures of existing substations to prevent further damage. For example, significant concrete corrosion has been observed in some substations in a certain city. At a depth of approximately 5 cm above the ground, the mortar layer on the concrete surface easily peels off, exposing the internal aggregate, resulting in a decrease in the actual strength of the concrete of approximately 5 MPa. In some regions, corrosion is even more severe, with concrete foundations commonly exhibiting symptoms such as surface peeling, aggregate exposure, and salt precipitation. These problems pose a significant threat to the normal operation of power distribution facilities. Therefore, in saline-alkali soil areas, strengthening the corrosion protection of existing substation concrete structures becomes particularly important.

[0003] Currently, various coating materials and technologies exist on the market aimed at improving the resistance of concrete to saline soil erosion. These mainly include three types: surface film-forming coatings, pore-sealing coatings, and hydrophobic impregnation coatings. However, in practical applications, due to the complex chemical composition of saline soil environments, existing coating materials often experience performance degradation under long-term exposure, failing to provide effective protection. Furthermore, the harsh environmental conditions in saline soil regions require coating materials to maintain good adhesion and integrity even under extreme conditions; however, current products typically fail to meet this requirement. Critical infrastructure such as transmission towers and power distribution equipment are highly susceptible to corrosion in saline soil environments, with their surface mortar layers easily detaching and peeling off, leading to reduced load-bearing capacity, shortened service life, and significant risks to the stable operation of power systems.

[0004] Chinese invention patent application CN117487416A discloses a durable protective coating for cement-based concrete and its application. The coating is made from the following raw materials in parts by weight: 100 parts liquid mixture and 150 parts powder mixture. The liquid mixture includes 100 parts emulsion, 1-3 parts wetting and dispersing agent, 2-10 parts thickener, 10-50 parts composite inert filler, and 0.5-2 parts defoamer. The powder mixture includes 60-100 parts cement, 0-10 parts fly ash, and 0-20 parts quartz sand. However, as a wetting and dispersing agent, sodium hexametaphosphate selected in this invention may decompose under specific conditions (such as high temperature and high humidity), thus affecting the stability of the coating. Polycarboxylate or sodium polyacrylate is easily affected by ultraviolet radiation and oxidation in outdoor environments, leading to a decline in coating performance.

[0005] Chinese utility model patent application CN216195535U discloses a concrete protective coating structure, including a cement base layer, a cement-based penetrating crystalline layer, an acrylic breathable elastic layer, a basalt flake fluorosilicone anti-carbonation layer, and an anti-detachment frame. The cement-based penetrating crystalline layer covers the cement base layer, and the two ends of the anti-detachment frame are respectively embedded in the cement base layer and the cement-based penetrating crystalline layer. The acrylic breathable elastic layer and the basalt flake fluorosilicone anti-carbonation layer are sequentially covered on the cement-based penetrating crystalline layer. However, the acrylic breathable elastic layer has relatively weak weather resistance and UV resistance, and is prone to aging and cracking when exposed to sunlight for a long time.

[0006] Chinese invention patent application CN112143313A discloses a polymer concrete protective coating material, prepared by mixing an aqueous solution and a mixture. The aqueous solution comprises 60-70 parts by weight of an aqueous acrylic resin emulsion, 5-10 parts by weight of an aqueous MMA resin emulsion, 5-10 parts by weight of an aqueous polyurea, 2-3 parts by weight of an alkoxysilane, 3-5 parts by weight of potassium silicate, and 2-3 parts by weight of a silicate. The mixture comprises 10-15 parts by weight of titanium dioxide, 3-5 parts by weight of silica powder, 5-9 parts by weight of diatomaceous earth, 0.3-0.5 parts by weight of a defoamer, 0.3-0.5 parts by weight of a dispersant, and 1-2 parts by weight of a thickener. This material can be used to maintain concrete structures and can prevent repaired concrete structures from being damaged again for a long time. However, the aqueous MMA resin emulsion is highly sensitive to humidity; high humidity conditions may cause the coating to blister or peel off, and potassium silicate may increase the brittleness of the coating, reducing its impact resistance.

[0007] Chinese utility model patent application CN218951293U discloses a coating anti-corrosion structure for concrete substrates. The coating anti-corrosion structure includes a water-based polyvinylidene chloride (PVDC) sealing primer coating, a water-based PVDC intermediate coating, and a water-based PVDC topcoat coating, sequentially applied from the inside to the outside of the concrete substrate's outer surface. Compared with existing technologies, this invention's coating anti-corrosion structure exhibits excellent water resistance, salt water resistance, and chloride ion penetration resistance, with very low total VOC emissions during the coating process, providing a high-performance, environmentally friendly coating material for concrete substrate anti-corrosion. However, water-based PVDC coatings have poor abrasion resistance and are easily subject to mechanical wear or scratches.

[0008] Chinese invention patent application CN105174900A discloses a method for preparing a sulfate-resistant coating material for concrete structures, comprising the following steps: Step 1: Using dead-burned magnesium oxide powder as an alkaline component and potassium dihydrogen phosphate as an acidic component, and adding a composite retarder, to prepare potassium magnesium phosphate cement; Step 2: Taking the potassium magnesium phosphate cement obtained in Step 1, silica fume, and limestone powder, mixing to prepare potassium magnesium phosphate cement-based material powder; then adding water glass, polypropylene fiber, and water to the prepared potassium magnesium phosphate cement-based material powder to prepare a potassium magnesium phosphate cement-based material slurry, which is the sulfate-resistant coating material for concrete structures. However, polypropylene fiber has a low melting point and is not resistant to high temperatures, which may limit the application of the coating in high-temperature environments.

[0009] At present, coatings may not be able to resist the effects of environmental factors (such as ultraviolet rays, temperature changes, etc.) for a long time, leading to coating aging, chalking or peeling; they lack self-healing ability, and once cracks or damage occur, external intervention is required for repair, otherwise the overall protective effect of the coating will be affected. Summary of the Invention

[0010] To address the problems existing in the prior art, the present invention aims to provide a concrete composite coating suitable for power transmission and substation structures in saline-alkali soil areas and its preparation method. The design of the composite coating of the present invention fully considers the compatibility and synergistic effect between the layers, as well as the adaptability to the external environment. By combining materials with different properties, it can effectively resist the erosion of saline soil and prevent the mortar layer on the concrete base surface from falling off and peeling off, thereby ensuring the stable operation and safe and reliable operation of the power system.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas, comprising a coating primer and a coating topcoat, wherein, by weight parts:

[0013] The coating primer consists of: 10-14 parts sodium methylsiloxane, 2 parts dispersant, and 86-90 parts water;

[0014] The coating topcoat includes: 100 parts silicate cement, 1 part nano silica, 3 parts microencapsulated material, 38 parts water, 3 parts water-reducing agent, and 0.5 to 1.5 parts fluorinated organosilicon compound.

[0015] Preferably, the dispersant is one of sodium dodecylbenzenesulfonate, sodium laurylate, and lauroyl diethanolamine.

[0016] Preferably, the silicate cement is ordinary silicate cement.

[0017] Preferably, the core material of the microencapsulated material is made of n-alkane paraffin, and the shell material is made of PMMA or polyurethane.

[0018] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.

[0019] Preferably, the fluorinated organosilicon compound is one of perfluorooctyltriethylsilane, perfluorodecyltrimethoxysilane, and trifluoropropylmethyldimethoxysilane.

[0020] Preferably, the bond strength between the concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas and the concrete substrate is 1.75-1.84 MPa.

[0021] Preferably, the concrete composite coating suitable for power transmission and transformation station structures in saline soil areas has a compressive strength of 50-59 MPa, a mass change rate of 0.60%-0.64%, and a compressive corrosion resistance coefficient of 0.91-0.95 under wet-dry cycling conditions with 5wt% sodium sulfate solution.

[0022] The present invention also provides a method for preparing a concrete composite coating suitable for power transmission and transformation station structures in saline soil areas, as described above, comprising:

[0023] A composite coating primer is applied to the concrete surface, and then a composite coating topcoat is applied to the composite coating primer surface. After curing, the concrete composite coating suitable for power transmission and transformation station structures in saline soil areas is formed.

[0024] Preferably, the preparation methods for the primer and topcoat are as follows:

[0025] Sodium methylsiloxane and dispersant are added to water and stirred until homogeneous to obtain the coating primer;

[0026] Silicate cement, nano-silica, and microencapsulated materials are mixed to obtain a dry mixture. Water, water-reducing agent, and fluorinated organosilicon compound are then added to the dry mixture and mixed to obtain a topcoat.

[0027] The present invention has the following beneficial effects:

[0028] This invention relates to a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas. The raw materials include a primer and a topcoat. The primer forms the underlying layer, ensuring fusion between the concrete component and the substrate, achieving uniform absorption and protection. The topcoat, on the other hand, provides the protective function to ensure the long-term safety and stability of the infrastructure. This invention uses a penetrating primer as the underlying layer, with sodium methylsiloxane as its key component. This component acts as a binder or reinforcing agent, providing excellent adhesion between the coating and the substrate. Due to the good water resistance and weather resistance of siloxanes, they can effectively protect the substrate from moisture erosion and environmental factors. For the topcoat, this invention proposes a composite formulation comprising silicate cement slurry, nano-sized silica, microencapsulated repair materials, and fluorinated organosilicon compounds. The core of this design lies in improving the overall performance of the coating through the synergistic effect of the components. First, the silicate cement slurry, as the matrix of the coating, provides structural strength, offering a stable support platform for the other components. The addition of nano-sized silica, with its high specific surface area and chemical stability, enhances the coating's hardness and wear resistance, and improves its microstructure. Subsequently, microencapsulated repair materials are embedded into the reinforced matrix. When the coating is subjected to external stress and microcracks appear, the microcapsules rupture and release the internal repair agent, filling the cracks and extending the coating's service life. This self-healing mechanism complements the reinforcing effect of the nano-sized silica, jointly improving the coating's durability. Finally, the introduction of fluorinated organosilicon compounds endows the coating surface with hydrophobic and antifouling properties, making it easy to clean, thereby further ensuring the coating's stability under various environmental conditions. In summary, this invention, through the rational selection and combination of the above materials, forms a coating system that combines high strength, self-healing capability, and protective function, with overall performance superior to that of a single material. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the composite coating structure formed in an embodiment of the present invention.

[0030] In the diagram, 1-component, 2-bottom layer, 3-top layer. Detailed Implementation

[0031] The technical solution of the present invention is described below with reference to specific embodiments. Each embodiment is an experimental example and provides real performance test data. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention relates to a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas, consisting of a base layer and a top layer, such as... Figure 1 As shown, the bottom layer ensures that the concrete components fuse with it, achieving a uniform absorption and protection effect. The top layer, on the other hand, provides protection to ensure the long-term safety and stability of the infrastructure.

[0033] Specifically, the concrete composite coating raw materials for power transmission and transformation station structures in saline-alkali soil areas, as described in this invention, include a coating primer and a coating topcoat, in parts by weight, wherein:

[0034] The coating primer consists of: 10-14 parts sodium methylsiloxane, 2 parts dispersant, and 86-90 parts water;

[0035] The coating topcoat includes: 100 parts silicate cement, 1 part nano silica, 3 parts microencapsulated material, 38 parts water, 3 parts water-reducing agent, and 0.5 to 1.5 parts fluorinated organosilicon compound.

[0036] In the above-described embodiments of the present invention, the microencapsulated material may adopt the following structure: the core material of the microencapsulated material is n-alkane paraffin, and the shell material is PMMA or polyurethane. The fluorinated organosilicon compound is one of perfluorooctyltriethylsilane, perfluorodecyltrimethoxysilane, and trifluoropropylmethyldimethoxysilane. The dispersant is one of sodium dodecylbenzenesulfonate, sodium laurylate, and lauroyl diethanolamine. The water-reducing agent is a polycarboxylate water-reducing agent. The silicate cement is ordinary silicate cement.

[0037] The present invention provides a method for preparing the above-mentioned concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas, comprising the following steps:

[0038] 1) Preparation of coating primer, including: adding sodium methylsiloxane and dispersant to water according to the formula, stirring evenly to obtain coating primer;

[0039] 2) Preparation of the coating topcoat, including: mixing silicate cement, nano-silica, and microencapsulated materials according to the specified ratio, and stirring evenly to obtain a dry mixture. Then, adding water, water-reducing agent, and fluorinated organosilicon compound to the dry mixture according to the specified ratio, and stirring to obtain the coating topcoat;

[0040] 3) When using, first apply a primer to the surface of the concrete component, and then apply a composite topcoat over the primer. The composite primer layer (the thickness of the primer should be controlled between 45 and 55 μm) and the composite topcoat layer (the thickness of the topcoat should be controlled between 1 and 2 mm) together form a concrete composite coating that resists saline soil erosion.

[0041] In the above-described scheme of this invention, the inner primer (i.e., the coating primer) mainly comprises sodium methylsiloxane. Therefore, this inner primer can form a stable chemical bond with the surface of the concrete substrate, providing a solid foundation and effectively filling the pores of the concrete, thereby enhancing the waterproof and moisture-proof capabilities of the substrate. The top layer contains nano-silica, fluorinated organosilicon compounds, and microencapsulated materials. Among them, nano-silica significantly enhances the density and hardness of the coating, improving impermeability and wear resistance. The fluorinated organosilicon compounds impart excellent hydrophobicity and chemical stability to the coating surface, while the microencapsulated materials, as intelligent repair agents, can automatically release repair agents when the coating suffers minor damage, filling cracks and extending the service life of the coating. In addition, the nano-silica in the top layer exists in the coating in a uniformly dispersed manner, forming a tiny barrier layer that effectively prevents the penetration of harmful substances such as moisture and salt. The fluorinated organosilicon compounds form a low surface energy protective film on the coating surface, improving the hydrophobicity and anti-fouling properties of the coating. The microencapsulated materials contain repair agents and shell materials. The shell material can rupture when the coating is damaged, releasing the repair agents to fill the cracks. In summary, this invention, through its dual-layer design, enables the composite coating to effectively protect concrete and prevent erosion by saline soil.

[0042] Example 1:

[0043] This embodiment is applicable to the concrete composite coating of power transmission and transformation station structures in saline soil areas. According to the following components by weight, the materials are prepared as follows: 100 parts of ordinary silicate cement, 3 parts of polycarboxylate superplasticizer, 2 parts of sodium dodecylbenzenesulfonate, 0.5 parts of perfluorooctyltriethylsilane, 12 parts of sodium methylsiloxane, 1 part of nano silica, 3 parts of microencapsulated material (shell material is polyurethane, core material is n-18ane), and 126 parts of water.

[0044] This embodiment describes a method for preparing a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas, including the following steps:

[0045] 1) Add 12 parts sodium methylsiloxane and 2 parts sodium dodecylbenzenesulfonate to 88 parts water, stir for 30 seconds until uniform, and obtain the coating primer.

[0046] 2) Mix 100 parts cement, 1 part nano silica and 3 parts microencapsulated material and stir for 30 seconds to obtain a dry mixture.

[0047] 3) Add 38 parts water, 3 parts water-reducing agent, and 0.5 parts perfluorooctyltriethylsilane to the dry mixture obtained in step 2), stir for 120 seconds, and obtain the coating topcoat.

[0048] 4) When using, first apply the composite coating primer to the concrete surface, and then apply the composite coating topcoat on top of the composite coating primer. The composite coating primer layer (the thickness of the primer should be controlled between 45~55μm) and the composite coating topcoat layer (the thickness of the topcoat should be controlled between 1~2mm) together form a concrete composite coating that resists saline soil erosion.

[0049] Example 2:

[0050] This embodiment is applicable to the concrete composite coating of power transmission and transformation station structures in saline soil areas. According to the following components by weight, the materials are prepared as follows: 100 parts of ordinary silicate cement, 3 parts of polycarboxylate superplasticizer, 2 parts of sodium dodecylbenzenesulfonate, 1 part of perfluorooctyltriethylsilane, 12 parts of sodium methylsiloxane, 1 part of nano silica, 3 parts of microencapsulated material (shell material is polyurethane, core material is n-18ane), and 126 parts of water.

[0051] This embodiment describes a method for preparing a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas, including the following steps:

[0052] 1) Add 12 parts sodium methylsiloxane and 2 parts sodium dodecylbenzenesulfonate to 88 parts water, stir for 30 seconds until uniform, and obtain the coating primer.

[0053] 2) Mix 100 parts cement, 1 part nano silica and 3 parts microencapsulated material and stir for 30 seconds to obtain a dry mixture.

[0054] 3) Add 38 parts water, 3 parts water-reducing agent, and 1 part perfluorooctyltriethylsilane to the dry mixture obtained in step 2), stir for 120 seconds, and obtain the coating topcoat.

[0055] 4) When using, first apply the composite coating primer to the concrete surface, and then apply the composite coating topcoat on top of the composite coating primer. The composite coating primer layer (the thickness of the primer should be controlled between 45~55μm) and the composite coating topcoat layer (the thickness of the topcoat should be controlled between 1~2mm) together form a concrete composite coating that resists saline soil erosion.

[0056] Example 3:

[0057] This embodiment is applicable to the concrete composite coating of power transmission and transformation station structures in saline soil areas. According to the weight parts, the following components are prepared: 100 parts of ordinary silicate cement, 3 parts of polycarboxylate superplasticizer, 2 parts of sodium dodecylbenzenesulfonate, 1.5 parts of perfluorooctyltriethylsilane, 12 parts of sodium methylsiloxane, 1 part of nano silica, 3 parts of microencapsulated material (shell material is polyurethane, core material is n-18ane), and 126 parts of water.

[0058] This embodiment describes a method for preparing a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas, including the following steps:

[0059] 1) Add 12 parts sodium methylsiloxane and 2 parts sodium dodecylbenzenesulfonate to 88 parts water, stir for 30 seconds until uniform, and obtain the coating primer.

[0060] 2) Mix 100 parts cement, 1 part nano silica and 3 parts microencapsulated material and stir for 30 seconds to obtain a dry mixture.

[0061] 3) Add 38 parts water, 3 parts water-reducing agent, and 1.5 parts perfluorooctyltriethylsilane to the dry mixture obtained in step 2), stir for 120 seconds, and obtain the coating topcoat.

[0062] 4) When using, first apply the composite coating primer to the concrete surface, and then apply the composite coating topcoat on top of the composite coating primer. The composite coating primer layer (the thickness of the primer should be controlled between 45~55μm) and the composite coating topcoat layer (the thickness of the topcoat should be controlled between 1~2mm) together form a concrete composite coating that resists saline soil erosion.

[0063] Example 4:

[0064] This embodiment is applicable to the concrete composite coating of power transmission and transformation station structures in saline soil areas. According to the following components by weight, the materials are prepared as follows: 100 parts of ordinary silicate cement, 3 parts of polycarboxylate superplasticizer, 2 parts of sodium dodecylbenzenesulfonate, 1 part of perfluorooctyltriethylsilane, 10 parts of sodium methylsiloxane, 1 part of nano silica, 3 parts of microencapsulated material (shell material is polyurethane, core material is n-18ane), and 128 parts of water.

[0065] This embodiment describes a method for preparing a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas, including the following steps:

[0066] 1) Add 10 parts sodium methylsiloxane and 2 parts sodium dodecylbenzenesulfonate to 90 parts water, stir for 30 seconds until uniform, and obtain the coating primer.

[0067] 2) Mix 100 parts cement, 1 part nano silica and 3 parts microencapsulated material and stir for 30 seconds to obtain a dry mixture.

[0068] 3) Add 38 parts water, 3 parts water-reducing agent, and 1 part perfluorooctyltriethylsilane to the dry mixture obtained in step 2), stir for 120 seconds, and obtain the coating topcoat.

[0069] 4) When using, first apply the composite coating primer to the concrete surface, and then apply the composite coating topcoat on top of the composite coating primer. The composite coating primer layer (the thickness of the primer should be controlled between 45~55μm) and the composite coating topcoat layer (the thickness of the topcoat should be controlled between 1~2mm) together form a concrete composite coating that resists saline soil erosion.

[0070] Example 5:

[0071] This embodiment is applicable to the concrete composite coating of power transmission and transformation station structures in saline soil areas. According to the weight parts, the following components are prepared: 100 parts of ordinary silicate cement, 3 parts of polycarboxylate superplasticizer, 2 parts of sodium dodecylbenzenesulfonate, 1 part of perfluorooctyltriethylsilane, 14 parts of sodium methylsiloxane, 1 part of nano silica, 3 parts of microencapsulated material (shell material is polyurethane, core material is n-18ane), and 124 parts of water.

[0072] This embodiment describes a method for preparing a concrete composite coating for power transmission and transformation station structures in saline-alkali soil areas, including the following steps:

[0073] 1) Add 14 parts sodium methylsiloxane and 2 parts sodium dodecylbenzenesulfonate to 86 parts water, stir for 30 seconds until uniform, and obtain the coating primer.

[0074] 2) Mix 100 parts cement, 1 part nano silica and 3 parts microencapsulated material and stir for 30 seconds to obtain a dry mixture.

[0075] 3) Add 38 parts water, 3 parts water-reducing agent, and 1 part perfluorooctyltriethylsilane to the dry mixture obtained in step 2), stir for 120 seconds, and obtain the coating topcoat.

[0076] 4) When using, first apply the composite coating primer to the concrete surface, and then apply the composite coating topcoat on top of the composite coating primer. The composite coating primer layer (the thickness of the primer should be controlled between 45~55μm) and the composite coating topcoat layer (the thickness of the topcoat should be controlled between 1~2mm) together form a concrete composite coating that resists saline soil erosion.

[0077] This invention employs a pull-out test method to determine the bond strength between the coating and the concrete substrate. The specific steps are as follows:

[0078] 1) Sample preparation: Select representative concrete specimens, ensuring the specimen surface is flat and clean. Then, evenly apply the developed composite coating material to the specimen surface; the coating thickness should meet the requirements of the actual application.

[0079] 2) Test tray installation: After the coating has fully cured, use a special adhesive to firmly attach the metal test tray to the coating surface, ensuring that there are no air bubbles or gaps between the test tray and the coating.

[0080] 3) Loading and Measurement: Connect the test disc to the pull-out test equipment and gradually increase the tensile force at a constant rate until the coating separates from the concrete substrate. Record the maximum tensile force value at the point of separation.

[0081] 4) Data processing: Calculate the bond strength between the coating and the substrate based on the maximum tensile force and the area of ​​the test plate.

[0082] The specific bond strength results for the concrete coatings prepared in Examples 1-5 are shown in Table 1:

[0083] Table 1

[0084]

[0085] As shown in Table 1, sodium methylsiloxane, under the influence of carbon dioxide and water in the air, can generate a hydrophobic substance. This substance can penetrate into the substrate, effectively blocking the capillaries in the cement grout and forming a hydrophobic film of a network of polymeric siloxane resin on the material surface. The formation of this film has a significant effect on enhancing the overall mechanical strength and bonding strength of the material.

[0086] In addition, fluorinated organosilicon compounds have chemical resistance properties, and surfaces treated with them can maintain good stability, which helps to maintain high bond strength over a long period of time.

[0087] The concrete coatings prepared in Examples 1-5 were applied to concrete for performance testing. A concrete specimen without any surface treatment and with the same curing method was used as blank sample 0. The compressive strength (MPa) data of different examples under the dry-wet cycle conditions of 5wt% sodium sulfate solution are shown in Table 2.

[0088] Table 2

[0089]

[0090] As can be seen from the test results listed in Table 2, the concrete composite coating material of this invention exhibits excellent performance in resisting saline soil erosion. The inner primer contains sodium methylsiloxane, a highly efficient waterproof and moisture-proof material. It can deeply penetrate into the concrete, react chemically with the concrete, and form a waterproof layer. This property effectively blocks the erosion of moisture and salt, providing strong protection for the concrete and preventing damage from saline soil.

[0091] The addition of nano-silica to the surface layer of the coating material significantly improves the strength and durability of the cement paste. Its nanoscale size allows it to fill the tiny pores in the cement paste, greatly enhancing the material's density and impermeability. Simultaneously, the introduction of fully fluorinated organosilicon compounds strengthens the concrete's impermeability, effectively blocking the intrusion of moisture and other harmful substances. This not only helps protect the internal structure of the concrete but also slows down the deterioration process to some extent, indirectly maintaining the concrete's strength. Table 3 shows the mass change rate and compressive strength / corrosion resistance coefficient of different embodiments after 150 cycles of wet-dry cycling in sulfate solution.

[0092] Table 3

[0093]

[0094] The data analysis results in Table 3 show that, compared to the coated specimens, the uncoated specimens exhibited a more significant increase in both the magnitude and rate of mass gain. This observation demonstrates the crucial role of the coating in preventing corrosive solutions from penetrating the capillary channels within the concrete.

[0095] After 150 cycles of wet and dry testing, the uncoated specimens showed the lowest compressive strength and corrosion resistance coefficient, indicating significant damage to the concrete material and the destructive effects of the corrosive solution on the uncoated specimens. Under the same experimental conditions, the coated specimens exhibited higher compressive strength and corrosion resistance coefficients, demonstrating that the coating effectively slowed the erosion rate of the corrosive solution on the concrete material, thereby improving the overall durability of the specimens.

[0096] The coating's corrosion resistance is primarily due to the sodium methylsiloxane used in its inner primer. This special material forms a strong chemical bond with the substrate surface, effectively blocking the penetration of corrosive media and providing a robust protective barrier for the substrate. Furthermore, the nano-silica and fluorinated organosilicon compounds added to the topcoat significantly enhance the coating's density and impermeability, increasing its strength and giving it greater resistance to corrosive substances such as sulfate solutions.

[0097] As can be seen from the above, the present invention has the following advantages:

[0098] 1) This invention uses sodium methylsilanolate as the bottom layer, which is essentially an organosilicon compound. Sodium methylsilanolate was chosen as the inner layer material due to its excellent adhesion, water resistance, and chemical resistance. It can adhere tightly to the substrate, forming a stable interface and providing a solid foundation for the outer layer.

[0099] 2) This invention improves the hardness and wear resistance of the entire coating by incorporating fluorinated organosilicon compounds and nano-silica into the surface layer. The fluorinated organosilicon compounds possess excellent hydrophobicity, oleophobicity, and chemical resistance. Within the coating, they can reduce surface tension, resulting in better hydrophobic properties. Simultaneously, they also enhance the coating's weather resistance and durability.

[0100] 3) Compared with the prior art, the anti-saline soil erosion concrete composite coating material proposed in this invention has the advantages of lower cost, simple construction and strong durability. These advantages together ensure the stability and safety of concrete facilities in the face of harsh environmental conditions such as saline soil erosion, and provide a strong guarantee for the long-term safe operation of infrastructure.

[0101] As can be seen from the above, the present invention fully considers the compatibility and synergistic effect between the layers, which work together to protect the concrete structure.

[0102] First, the inner primer uses sodium methylsilanolate as its main component. This material can form a stable chemical bond with the concrete substrate surface, providing a solid foundation for the entire coating system. The permeability and reactivity of sodium methylsilanolate enable it to effectively fill concrete pores, enhancing the substrate's waterproof and moisture-proof capabilities.

[0103] Next, nano-silica was introduced into the surface layer. Due to its small particle size and high specific surface area, nano-silica significantly enhances the coating's density and hardness, thereby improving its impermeability and abrasion resistance. This layer is designed to further enhance the coating's physical barrier function, providing more comprehensive protection for the concrete structure. In addition, fluorinated organosilicon compounds and microencapsulated materials were added to the surface layer. The fluorinated organosilicon compounds impart excellent hydrophobicity and chemical stability to the coating surface, giving it greater resistance to harsh environments such as saline soils. The microencapsulated materials, acting as a smart repair agent, can automatically release repair agents when minor damage occurs in the coating, filling cracks and extending the coating's service life.

[0104] By combining the aforementioned materials, this invention achieves a tight bond and synergistic effect between the layers of the composite coating. Therefore, the anti-saline soil erosion concrete composite coating material proposed in this invention has significant advantages in protecting concrete structures from saline soil erosion, providing strong protection for the long-term safe operation of infrastructure.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas, characterized in that, Its raw materials include a primer and a topcoat, in parts by weight, of which: The coating primer consists of: 10-14 parts sodium methylsiloxane, 2 parts dispersant, and 86-90 parts water; The coating topcoat includes: 100 parts silicate cement, 1 part nano silica, 3 parts microencapsulated material, 38 parts water, 3 parts water-reducing agent, and 0.5 to 1.5 parts fluorinated organosilicon compound.

2. The concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The dispersant is one of sodium dodecylbenzenesulfonate, sodium laurylate, and lauroyl diethanolamine.

3. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The silicate cement used is ordinary silicate cement.

4. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The core material of the microencapsulated material is made of n-alkane paraffin, and the shell material is made of PMMA or polyurethane.

5. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The water-reducing agent used is polycarboxylate water-reducing agent.

6. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The fluorinated organosilicon compound is one of perfluorooctyltriethylsilane, perfluorodecyltrimethoxysilane, and trifluoropropylmethyldimethoxysilane.

7. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The bond strength between the concrete composite coating and the concrete substrate, which is suitable for power transmission and transformation station structures in saline-alkali areas, is 1.75-1.84 MPa.

8. A concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 1, characterized in that, The concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas has a compressive strength of 50-59 MPa, a mass change rate of 0.60%-0.64%, and a compressive corrosion resistance coefficient of 0.91-0.95 under dry-wet cycling conditions with 5wt% sodium sulfate solution.

9. The method for preparing a concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas, as described in any one of claims 1-8, is characterized in that... include: A composite coating primer is applied to the concrete surface, and then a composite coating topcoat is applied to the composite coating primer surface. After curing, the concrete composite coating suitable for power transmission and transformation station structures in saline soil areas is formed.

10. The method for preparing a concrete composite coating suitable for power transmission and transformation station structures in saline-alkali soil areas according to claim 9, characterized in that, The preparation methods for the primer and topcoat are as follows: Sodium methylsiloxane and dispersant are added to water and stirred until homogeneous to obtain the coating primer; Silicate cement, nano-silica, and microencapsulated materials are mixed to obtain a dry mixture. Water, water-reducing agent, and fluorinated organosilicon compound are then added to the dry mixture and mixed to obtain a topcoat.

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