A two-component material and construction method for protecting the outer wall of a thin-walled aqueduct in cold regions

Abstract

The present application relates to the technical field of hydraulic engineering structure protection, in particular to a two-component material for protecting the outer wall of a thin-wall aqueduct in cold regions and a construction method thereof. The two-component material for protecting the outer wall of a thin-wall aqueduct in cold regions comprises A-component powder and B-component liquid, and the mass ratio of the A-component powder to the B-component liquid is 1:1-1.2. The A-component powder comprises the following components in parts by weight: white portland cement 40.0-50.0 parts; quartz sand 20.0-30.0 parts; heavy calcium powder 10.0-15.0 parts; silica fume 2.0-5.0 parts; and redispersible emulsion powder 1.0-3.0 parts. The B-component liquid comprises the following components in parts by weight: silicone-modified acrylic emulsion 70.0-85.0 parts; nano ATO slurry 15.0-30.0 parts; and silane coupling agent 0.5-1.5 parts. The present application forms an organic-inorganic hybrid protective coating through the cooperation of the powder and the liquid. The cement hydration product in the powder and the silicone-modified acrylic emulsion in the liquid form a hybrid structure with a rigid skeleton and a flexible network through interpenetrating crosslinking.

Description

Technical Field

[0001] This invention relates to the field of hydraulic engineering structure protection technology, specifically to a two-component material and construction method for the outer wall protection of thin-walled aqueducts in cold regions. Background Technology

[0002] Aqueducts, as a common water conveyance structure, are widely used in water conservancy projects in cold regions. The climate of cold regions is typically characterized by severe winters, large diurnal temperature variations, frequent freeze-thaw cycles, intense ultraviolet radiation in summer, and strong wind erosion, posing a severe challenge to the protection of the outer walls of thin-walled aqueduct structures.

[0003] To address the aforementioned environmental conditions, traditional technologies often employ solvent-based epoxy, polyurethane, or acrylic organic coatings as protective layers for the outer walls of aqueducts. However, these organic coatings have significantly different coefficients of thermal expansion compared to the concrete substrate. Under drastic temperature changes in cold regions, the mismatch between the coating and the concrete matrix leads to substantial thermal stress, easily causing cracking, peeling, and even flaking. Simultaneously, under strong ultraviolet radiation, the aging process of organic coatings accelerates, rapidly diminishing their elasticity and adhesion, further exacerbating the risk of cracking and failure. Furthermore, these coatings lack long-term adaptability to harsh environments such as repeated freeze-thaw cycles and wind erosion, resulting in a short protection period, which fails to meet the long-term, reliable protection requirements of aqueducts in cold regions. Therefore, existing aqueduct outer wall protection technologies suffer from cracking, peeling, and insufficient durability due to the mismatch in thermal expansion coefficients between the coating and the substrate, and poor weather resistance.

[0004] In recent years, nano-ATO, as a novel spectrally selective thermal insulation material, has attracted widespread attention in the field of building energy-saving coatings. ATO nanoparticles possess a unique free-carrier plasma resonance effect, enabling selective absorption and reflection in the near-infrared band (780–2500 nm) of the solar spectrum, while maintaining high transmittance in the visible light region. Studies have shown that transparent thermal insulation coatings using ATO as a functional filler can reduce the temperature difference in simulated environments by 5–10°C, exhibiting significant thermal insulation and energy-saving effects. However, current research on ATO thermal insulation coatings mainly focuses on transparent thermal insulation applications such as architectural glass and vehicle windows; its application in the protection of concrete structures' exterior walls, especially in the harsh service environment of thin-walled aqueducts in cold regions, has not yet been reported. Introducing the spectrally selective thermal insulation function of ATO into the aqueduct's exterior wall protection system holds promise for solving durability problems such as cracking and peeling caused by temperature stress in coatings from the perspective of solar thermal radiation management. Summary of the Invention

[0005] (a) Technical problems to be solved In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a two-component material and construction method for the outer wall protection of thin-walled aqueducts in cold regions, so as to solve the technical problems of cracking, peeling and insufficient durability caused by the mismatch of thermal expansion coefficients between the coating and the substrate and poor weather resistance in the prior art.

[0006] (II) Technical Solution In a first aspect, the present invention provides a two-component material for the outer wall protection of thin-walled aqueducts in cold regions, comprising a component A powder and a component B liquid, wherein the mass ratio of the component A powder to the component B liquid is 1:1-1.2. The A component powder comprises the following components in parts by weight: 40.0-50.0 parts of white silicate cement; Quartz sand 20.0-30.0 parts; 10.0-15.0 parts of heavy calcium carbonate powder; 2.0-5.0 parts silica fume; 1.0-3.0 parts of redispersible latex powder; The B component liquid contains the following components in parts by weight: 70.0-85.0 parts of silicone-modified acrylic emulsion; Nano ATO slurry, 15.0-30.0 parts; 0.5-1.5 parts of silane coupling agent.

[0007] Optionally, the white silicate cement has a strength grade of 42.5R, 52.5R, or 62.5R.

[0008] Optionally, the particle size range of the quartz sand is 70-140 mesh.

[0009] Optionally, the particle size of the heavy calcium carbonate powder is 350-400 mesh.

[0010] Optionally, the solid content of the silicone-modified acrylic emulsion is 40-50%.

[0011] Optionally, the solid content of the nano-ATO slurry is 20-25%.

[0012] Optionally, the content of the silane coupling agent is 0.8-1.2 parts by weight.

[0013] Optionally, the A component powder further comprises 3.0-8.0 parts by weight of lime powder.

[0014] Optionally, the A component powder may further include one or more of the following: 0.1-0.3 parts by weight of hydroxypropyl methylcellulose, 0.2-0.5 parts by weight of wood fiber, 0.2-0.5 parts by weight of polycarboxylate-based powder water-reducing agent, 0.1-0.2 parts by weight of defoamer, and 0.1-5.0 parts by weight of titanium dioxide.

[0015] Optionally, the A component powder comprises 0.15-0.25 parts by weight of hydroxypropyl methylcellulose, 0.3-0.4 parts by weight of wood fiber, 0.3-0.4 parts by weight of polycarboxylate-based powder water-reducing agent, 0.12-0.18 parts by weight of defoamer, and 1.0-4.0 parts by weight of titanium dioxide.

[0016] Optionally, the B component liquid further comprises one or more of the following: 0-10.0 parts by weight of water, 0.1-0.3 parts by weight of wetting agent, 0.2-0.5 parts by weight of defoamer, 1.0-2.0 parts by weight of film-forming aid, 0.1-0.2 parts by weight of preservative, and 0-1.0 parts by weight of thickener.

[0017] Optionally, the B component liquid contains 0.15-0.25 parts by weight of wetting agent, 0.25-0.45 parts by weight of defoamer, 1.2-1.8 parts by weight of film-forming aid, 0.12-0.18 parts by weight of preservative and 0.2-0.8 parts by weight of thickener.

[0018] Optionally, the thickener is a nonionic polyurethane thickener.

[0019] Optionally, the nano-ATO slurry is prepared by mixing nano-ATO powder modified with a surface silane coupling agent and modified nano-TiO2 powder at a volume ratio of 10:1.

[0020] This invention provides a construction method for the aforementioned two-component material, comprising the following steps: (1) Base surface treatment: Remove the attached materials on the concrete base surface and spray inorganic silicate penetrating crystallizing material for curing; (2) Material preparation and construction: Mix the powder of component A and the liquid of component B in proportion and apply them to the treated substrate using a roller coating process; (3) Curing: Dry curing for 7 days after construction to form a complete protective layer.

[0021] Optionally, the removal of deposits on the concrete substrate in step (1) involves using power tools to thoroughly remove loose mortar, sharp corners, debris, and contaminants from the concrete surface.

[0022] The present invention relates to the application of the two-component material described herein in the outer wall protection of thin-walled aqueducts in cold regions.

[0023] (III) Beneficial Effects This invention combines powder and liquid components to form an organic-inorganic hybrid protective coating. The cement hydration products in the powder and the organosilicon-modified acrylic emulsion in the liquid form a hybrid structure combining a rigid framework and a flexible network through interpenetrating crosslinking. This structure not only provides strong adhesion and high bonding strength to the concrete substrate, but more importantly, it combines rigidity and flexibility, effectively coordinating the differences in expansion and contraction between the coating and the concrete substrate caused by temperature changes. This buffers and disperses temperature stress, fundamentally overcoming the cracking and peeling defects easily caused by the mismatch of thermal expansion coefficients in traditional organic coatings, thus improving the coating's crack resistance and long-term durability.

[0024] Furthermore, the nano-ATO slurry in the liquid material exhibits selective properties regarding the solar spectrum—maintaining high transmittance in the visible light region while strongly reflecting and blocking near-infrared light, which accounts for approximately 50% of solar radiation. This characteristic enables the coating to efficiently reflect solar radiation heat, significantly reducing the temperature rise of the aqueduct's outer wall under sunlight. This effectively alleviates the problems of thermal expansion of the outer wall of the aqueduct in cold regions, the huge internal and external temperature differences caused by water freezing, and repeated freeze-thaw cycles, thus suppressing freeze-thaw damage from a thermodynamic perspective.

[0025] Meanwhile, the introduction of silane coupling agents and organosilicon components endows the coating surface with durable and strong hydrophobicity, which can effectively block the intrusion of moisture and harmful ions, and achieve the surface self-cleaning function, maintaining the appearance of the aqueduct for a long time and reducing maintenance costs. Detailed Implementation

[0026] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below through specific embodiments.

[0027] The protective system of this invention is particularly suitable for cold regions with severe winters, large diurnal temperature differences, frequent freeze-thaw cycles, and strong ultraviolet radiation and strong wind erosion in summer, providing long-lasting, reliable, and multifunctional external wall protection for thin-walled aqueduct structures, including heat insulation, impermeability, and self-cleaning.

[0028] The powder of the present invention comprises white silicate cement 52.5R, lime powder, quartz sand, heavy calcium carbonate powder, silica fume, redispersible latex powder, hydroxypropyl methylcellulose, wood fiber, polycarboxylate powder, defoamer and titanium dioxide.

[0029] Among them, white silicate cement 52.5R, as the main cementitious material, can penetrate and react with cement hydration products after being sprayed onto the concrete surface, generating insoluble crystals to seal micro-cracks and improve the density of the matrix; lime powder can improve workability and participate in the later carbonation reaction to enhance density; specific mesh size quartz sand and heavy calcium carbonate powder, as aggregates and fillers, can optimize the bulk density and mechanical strength of the coating; the micro-filling effect of silica fume can further refine the pore structure of the coating; redispersible latex powder re-emulsifies after the powder comes into contact with water, and synergistically enhances the toughness of the coating with the emulsion in the liquid; hydroxypropyl methylcellulose and wood fiber work together to improve the water retention, anti-sagging and crack resistance of the slurry; polycarboxylate powder, as a high-efficiency water-reducing agent, ensures good fluidity of the slurry at low water-cement ratios; defoamer is used to eliminate air bubbles introduced during the mixing process to ensure the density of the coating; titanium dioxide mainly provides hiding power and the ability to reflect ultraviolet rays.

[0030] The liquid component of this invention comprises silicone-modified acrylic emulsion, nano-ATO slurry, water, wetting agent, defoamer, film-forming aid, preservative, silane coupling agent, and thickener.

[0031] Organosilicon-modified acrylic emulsion serves as the main film-forming substance and organic phase. The organosiloxane bonds in its molecular chain significantly enhance the coating's resistance to UV aging, hydrophobicity, and low-temperature flexibility. Nano-sized antimony-doped tin oxide particles in the nano-ATO slurry exhibit high reflectivity in the near-infrared band of sunlight, directly reducing the solar radiation heat absorbed by the coating and thus minimizing the temperature rise of the aqueduct's outer wall. Water is used to adjust the viscosity and solids content of the liquid. Wetting agents facilitate the full wetting and dispersion of powder particles by the liquid. Film-forming aids promote the fusion of emulsion particles at lower temperatures, forming a continuous and dense coating. Preservatives prevent mold growth during storage. Silane coupling agents act as a bridge, reacting with the hydroxyl groups on the surface of inorganic powders at one end and binding to organic polymer chains at the other, greatly enhancing the interfacial adhesion between the organic and inorganic phases. Thickeners are used to adjust the application viscosity of the liquid, ensuring good leveling and anti-splatter properties during roller coating.

[0032] In the powder of this invention, the content of white silicate cement 52.5R can be 40.0-50.0 parts by weight, lime powder 3.0-8.0 parts by weight, quartz sand (70-140 mesh) 20.0-30.0 parts by weight, heavy calcium carbonate powder (400 mesh) 10.0-15.0 parts by weight, silica fume 2.0-5.0 parts by weight, redispersible latex powder 1.0-3.0 parts by weight, hydroxypropyl methylcellulose 0.1-0.3 parts by weight, wood fiber 0.2-0.5 parts by weight, polycarboxylate powder 0.2-0.5 parts by weight, defoamer 0.1-0.2 parts by weight, and titanium dioxide 0.1-5.0 parts by weight.

[0033] In the liquid component of this invention, the content of organosilicon-modified acrylic emulsion (50% solid content) can be 70.0-85.0 parts by weight, nano-ATO slurry (20% solid content) can be 15.0-30.0 parts by weight, water can be 0-10.0 parts by weight, wetting agent can be 0.1-0.3 parts by weight, defoamer can be 0.2-0.5 parts by weight, film-forming aid can be 1.0-2.0 parts by weight, preservative can be 0.1-0.2 parts by weight, silane coupling agent can be 0.5-1.5 parts by weight, and thickener (nonionic polyurethane) can be 0-1.0 parts by weight.

[0034] The preparation method of the nano-ATO slurry of the present invention includes the following steps: First, the surface of the nano-ATO powder is modified. The specific steps are as follows: Preparation of modified solution: Weigh 2.0% of the weight of ATO powder silane coupling agent (preferably KH-570), add it to a measured amount of 95% anhydrous ethanol, and stir until the mixture is homogeneous.

[0035] Ultrasonic dispersion: Add nano-ATO powder to the above modified liquid and place it in an ultrasonic dispersion device for 30 minutes to ensure that the ATO powder is fully dispersed.

[0036] Reflux reaction: The ultrasonically treated mixture is transferred to a container equipped with a reflux device and refluxed for 3 hours with continuous stirring. This step aims to promote a chemical reaction between KH-570 and the hydroxyl groups on the surface of ATO powder, achieving surface grafting.

[0037] Washing and drying: After the reaction, the product was repeatedly washed with anhydrous ethanol to remove unreacted coupling agent. Finally, it was vacuum dried at 70-80℃ to obtain preliminarily surface-modified nano-ATO powder.

[0038] Secondly, the modification treatment of nano-TiO2 powder involves the following specific steps: Raw material and parameter selection: Weigh out the measured amount of nano TiO2 powder (preferably rutile type with better UV resistance), and use KH-570 at 4% of the weight of TiO2 powder.

[0039] Modification treatment: Following the modification process of ATO powder, nano-TiO2 was treated in 95% anhydrous ethanol medium. After ultrasonic dispersion, a reflux stirring reaction was carried out for 2 hours, followed by washing and vacuum drying to finally obtain surface-modified nano-TiO2 powder.

[0040] The "preliminarily modified ATO powder" and "modified nano-TiO2 powder" prepared in the above steps were mechanically mixed at a volume ratio of 10:1. The composite material obtained after uniform mixing is the final nano-ATO material used in this formulation.

[0041] The construction method of the two-component material of the present invention includes the following steps: Step S10, Base Surface Treatment: Remove contaminants from the concrete surface, then spray with an inorganic silicate penetrating crystalline material. Specifically, first, use power tools such as an angle grinder and wire brush to thoroughly remove laitance, dust, oil, loose particles, and biological deposits from the outer surface of the aqueduct concrete, exposing a solid and clean base layer. Then, using a low-pressure spraying device, evenly spray the inorganic silicate penetrating crystalline material onto the treated base surface. This material can penetrate into the capillaries of the concrete surface, reacting to form insoluble crystals, blocking the pores, enhancing the surface strength and impermeability of the substrate, and providing a stronger and denser adhesion base for subsequent protective coatings. The inorganic silicate penetrating crystalline material can be a commercially available cement-based penetrating crystalline waterproof coating.

[0042] Step S20, Coating: Mix the liquid and powder materials evenly and apply them to the treated substrate using a roller coating process. Specifically, first pour the liquid material into a mixing container, and slowly and evenly add the powder material while stirring at a medium speed of 300-500 rpm. After the addition is complete, increase the stirring speed to 800-1200 rpm and continue stirring for 3-5 minutes until a fine slurry with uniform color, no particles, and no lumps is obtained. After stirring, let it stand for 2-3 minutes to defoam. Use a wool roller or similar roller coating tool to evenly coat the mixed slurry onto the outer wall surface of the aqueduct treated in step S10.

[0043] Step S30, Curing: After application, dry cure for 3 to 7 days under ambient conditions. Specifically, after construction, ensure the coating is protected from rain, direct sunlight, or strong winds during the curing period. Allow it to dry naturally at an ambient temperature of 5-35℃ and a relative humidity not exceeding 85%. During curing, the cement in the coating will complete its main hydration process, the polymer emulsion will fully form a film, and the organic-inorganic hybrid structure will tend to stabilize. Typically, the coating will achieve initial hardening after 3 days and obtain all performance requirements after 7 days. This curing process is simple, has low requirements for the construction environment, and is particularly suitable for cold-region outdoor operations.

[0044] Example 1: In the powder of the two-component material described in this embodiment, the content of white silicate cement 52.5R is 45.0 parts by weight, lime powder is 5.0 parts by weight, quartz sand (70-140 mesh) is 25.0 parts by weight, heavy calcium carbonate powder (400 mesh) is 12.0 parts by weight, silica fume is 3.5 parts by weight, redispersible latex powder is 2.0 parts by weight, hydroxypropyl methylcellulose is 0.2 parts by weight, wood fiber is 0.3 parts by weight, polycarboxylate ether powder is 0.3 parts by weight, defoamer polyether modified siloxane is 0.1 parts by weight, and titanium dioxide is 2.0 parts by weight.

[0045] In this embodiment, the liquid component contains 78.0 parts by weight of silicone-modified acrylic emulsion (50% solid content), 18.0 parts by weight of nano-ATO slurry (20% solid content), 2.5 parts by weight of water, 0.2 parts by weight of wetting agent alkyl naphthalene sulfonate, 0.3 parts by weight of defoamer polyether-modified siloxane, 1.2 parts by weight of film-forming aid dodecyl alcohol ester, 0.1 parts by weight of preservative methylisothiazolinone, 0.8 parts by weight of silane coupling agent, and 0.4 parts by weight of thickener (nonionic polyurethane).

[0046] The construction method for the two-component material described in this embodiment includes the following steps: S10. Surface preparation and pretreatment: Before construction, thoroughly clean the surface to remove any loose mortar, sharp protrusions, and contaminants. Then, uniformly spray an inorganic silicate penetrating crystallizing material for curing and pretreatment to enhance the interfacial bonding.

[0047] S20. Coating preparation and application: Mix the powder and liquid components precisely at a mass ratio of 1:1 and stir thoroughly; apply using a roller coating process, and strictly control the coating thickness to 500 μm.

[0048] S30. Curing and shaping: After the coating operation is completed, a 7-day dry curing period is carried out to ensure that the coating is fully cured and shaped.

[0049] Example 2: In the powder of the two-component material described in this embodiment, the content of white silicate cement 52.5R is 48.0 parts by weight, lime powder is 7.0 parts by weight, quartz sand (70-140 mesh) is 28.0 parts by weight, heavy calcium carbonate powder (400 mesh) is 14.0 parts by weight, silica fume is 4.5 parts by weight, redispersible latex powder is 3.0 parts by weight, hydroxypropyl methylcellulose is 0.3 parts by weight, wood fiber is 0.5 parts by weight, polycarboxylate ether powder is 0.4 parts by weight, polyether-modified siloxane is 0.2 parts by weight, and titanium dioxide is 4.0 parts by weight.

[0050] In this embodiment, the liquid component contains 70.0 parts by weight of silicone-modified acrylic emulsion (50% solid content), 25.0 parts by weight of nano-ATO slurry (20% solid content), 5.0 parts by weight of water, 0.3 parts by weight of wetting agent alkyl naphthalene sulfonate, 0.4 parts by weight of polyether-modified siloxane, 1.8 parts by weight of film-forming aid dodecyl alcohol ester, 0.2 parts by weight of preservative methylisothiazolinone, 1.2 parts by weight of silane coupling agent, and 0.8 parts by weight of thickener (nonionic polyurethane).

[0051] The construction method of the two-component material described in this embodiment is the same as that in Embodiment 1.

[0052] Comparative Example 1 (the silicone-modified acrylic emulsion was replaced with an acrylic emulsion): In the powder of the two-component material described in this comparative example, the content of white silicate cement 52.5R is 45.0 parts by weight, lime powder is 5.0 parts by weight, quartz sand (70-140 mesh) is 25.0 parts by weight, heavy calcium carbonate powder (400 mesh) is 12.0 parts by weight, silica fume is 3.5 parts by weight, redispersible latex powder is 2.0 parts by weight, hydroxypropyl methylcellulose is 0.2 parts by weight, wood fiber is 0.3 parts by weight, polycarboxylate ether powder is 0.3 parts by weight, polyether-modified siloxane is 0.1 parts by weight, and titanium dioxide is 2.0 parts by weight.

[0053] In this comparative example, the liquid composition contains 70.0 parts by weight of acrylic emulsion (50% solid content), 18.0 parts by weight of nano-ATO slurry (20% solid content), 2.5 parts by weight of water, 0.2 parts by weight of wetting agent, 0.3 parts by weight of polyether-modified siloxane, 1.2 parts by weight of film-forming aid, 0.1 parts by weight of preservative methylisothiazolinone, 0.8 parts by weight of silane coupling agent, and 0.4 parts by weight of thickener (nonionic polyurethane).

[0054] The construction method of the two-component material described in this comparative example is the same as that in Example 1.

[0055] Comparative Example 2 (using an equal amount of calcium carbonate instead of nano-ATO slurry): In the powder of the two-component material described in this comparative example, the content of white silicate cement 52.5R is 45.0 parts by weight, lime powder is 5.0 parts by weight, quartz sand (70-140 mesh) is 25.0 parts by weight, heavy calcium carbonate powder (400 mesh) is 12.0 parts by weight, silica fume is 3.5 parts by weight, redispersible latex powder is 2.0 parts by weight, hydroxypropyl methylcellulose is 0.2 parts by weight, wood fiber is 0.3 parts by weight, polycarboxylate ether powder is 0.3 parts by weight, polyether-modified siloxane is 0.1 parts by weight, and titanium dioxide is 2.0 parts by weight.

[0056] In the liquid component of this comparative example, the content of silicone-modified acrylic emulsion (50% solid content) is 78.0 parts by weight, F150 calcium carbonate is 18.0 parts by weight, water is 2.5 parts by weight, wetting agent is 0.2 parts by weight, polyether-modified siloxane is 0.3 parts by weight, film-forming aid is 1.2 parts by weight, preservative methylisothiazolinone is 0.1 parts by weight, silane coupling agent is 0.8 parts by weight, and thickener (nonionic polyurethane) is 0.4 parts by weight.

[0057] The construction method of the two-component material described in this comparative example is the same as that in Example 1.

[0058] Experimental example: This field verification test selected a typical cold-region water conveyance aqueduct located in Ningxia. This aqueduct, with its thin-walled concrete structure, is subjected to harsh service environments, including strong ultraviolet radiation, significant diurnal temperature variations, and winter freeze-thaw cycles, placing extremely high demands on the weather resistance and stability of the protective materials. To scientifically verify the actual protective effect of the materials used in the embodiments and comparative examples of this invention, approximately 300 m of the outer wall of this aqueduct was selected. 2 The area was used as a test section for coating application.

[0059] After the coating has cured and hardened, the overall appearance is smooth and the color is uniform. After a complete irrigation cycle, on-site visual inspection showed that the coating surface had no peeling, bulging, or discoloration, and the appearance remained intact, demonstrating excellent weather resistance.

[0060] To objectively and quantitatively evaluate the protective effect, systematic performance tests were conducted on Examples 1-2 and Comparative Examples 1-2. The main test results are summarized below: Table 1: Performance test results of the two-component materials used in Examples 1-2 and Comparative Examples 1-2

[0061] As shown in Table 1, compared with Comparative Example 1, the bonding strength of Example 1 was significantly improved and the impermeability reached W12. This confirms that after introducing the silicone-modified acrylic emulsion, it formed a hybrid network with inorganic hydration products, which greatly improved the density and adhesion. Comparing Example 1 and Comparative Example 2, it can be seen that Comparative Example 2, which lacks nano-ATO slurry, showed an increased carbonization depth to 33.0 mm and a decrease in freeze-thaw resistance to F150 after carbonization and freeze-thaw cycles. This indicates that the addition of nano-ATO effectively reflected solar radiation heat, reduced the thermal stress caused by the temperature difference between the inside and outside of the coating, and fundamentally improved the freeze-thaw resistance.

[0062] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A two-component material for the outer wall protection of thin-walled aqueducts in cold regions, characterized in that, It consists of component A powder and component B liquid, wherein the mass ratio of component A powder to component B liquid is 1:1-1.2; The A component powder comprises the following components in parts by weight: 40.0-50.0 parts of white silicate cement; Quartz sand 20.0-30.0 parts; 10.0-15.0 parts of heavy calcium carbonate powder; 2.0-5.0 parts silica fume; 1.0-3.0 parts of redispersible latex powder; The B component liquid contains the following components in parts by weight: 70.0-85.0 parts of silicone-modified acrylic emulsion; Nano ATO slurry, 15.0-30.0 parts; 0.5-1.5 parts of silane coupling agent.

2. The two-component material according to claim 1, characterized in that, In the powder component A, the white silicate cement has a strength grade of 42.5R, 52.5R, or 62.5R; The particle size range of the quartz sand is 70-140 mesh; The particle size of the heavy calcium carbonate powder is 350-400 mesh.

3. The two-component material according to claim 1 or 2, characterized in that, In the B component liquid, the solid content of the organosilicon-modified acrylic emulsion is 40-50%; The solid content of the nano-ATO slurry is 20-25%.

4. The two-component material according to claim 1 or 2, characterized in that, In the liquid component B, the amount of the silane coupling agent is 0.8-1.2 parts by weight.

5. The two-component material according to claim 1 or 2, characterized in that, The A component powder also contains 3.0-8.0 parts by weight of lime powder.

6. The two-component material according to claim 1 or 2, characterized in that, The A component powder also contains one or more of the following components: 0.1-0.3 parts by weight of hydroxypropyl methylcellulose, 0.2-0.5 parts by weight of wood fiber, 0.2-0.5 parts by weight of polycarboxylate powder water-reducing agent, 0.1-0.2 parts by weight of defoamer, and 0.1-5.0 parts by weight of titanium dioxide.

7. The two-component material according to claim 1 or 2, characterized in that, The B component liquid also contains one or more of the following components: 0-10.0 parts by weight of water, 0.1-0.3 parts by weight of wetting agent, 0.2-0.5 parts by weight of defoamer, 1.0-2.0 parts by weight of film-forming aid, 0.1-0.2 parts by weight of preservative and 0-1.0 parts by weight of thickener.

8. The two-component material according to claim 7, characterized in that, The thickener is a nonionic polyurethane thickener; The nano-ATO slurry is prepared by mixing nano-ATO powder modified with a surface silane coupling agent and modified nano-TiO2 powder at a volume ratio of 10:

1.

9. A method for constructing a two-component material as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Surface preparation: Remove any adhering substances from the concrete surface and spray an inorganic silicate penetrating crystallizing material for curing. S2. Material preparation and application: Mix component A powder and component B liquid in a certain proportion and apply them to the treated substrate using a roller coating process. S3. Maintenance: Dry curing for 3-7 days after construction to form a complete protective layer.

10. The application of a two-component material as described in any one of claims 1 to 8 in the protection of the outer wall of a thin-walled aqueduct in cold regions.

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