Low-crack high-corrosion-resistant concrete for wind power tower and preparation method thereof

Abstract

This application relates to the field of concrete, specifically disclosing a low-crack, high-corrosion-resistant concrete for wind turbine towers and its preparation method. The low-crack, high-corrosion-resistant concrete for wind turbine towers, by weight, comprises the following components: cement, 410-420 parts; mineral powder, 62-67 parts; glass microspheres, 70-75 parts; silica fume, 40-42 parts; basalt gravel, 1050-1150 parts; natural sand, 640-660 parts; admixture composition, 9.5-10 parts; and water, 120-130 parts. The admixture composition includes self-healing capsules, loaded Bacillus spores, and a corrosion-inhibiting complex. The concrete of this application exhibits excellent strength recovery, high impermeability, and high corrosion resistance. During the concrete pouring and molding process, the number of internal and surface microcracks is significantly reduced, resulting in high internal density and a good appearance.

Description

Technical Field

[0001] This application relates to the technical field of concrete, and in particular to a low-crack, high-corrosion-resistant concrete for wind turbine towers and a method for preparing the same. Background Technology

[0002] Concrete, as the most widely used building material globally, plays a crucial role in the construction industry. It is extensively applied in various construction projects, such as high-rise buildings, bridges, tunnels, and marine engineering, providing solid support for modern infrastructure construction. However, the durability of concrete has always been a research hotspot in this field. Under harsh environments, such as the high-salt environment of marine engineering, the complex stress environment of bridges and tunnels, and the low-temperature environment of buildings in high-altitude and cold regions, concrete is prone to strength reduction, durability deterioration, and long-term performance instability due to the formation of micro-cracks. In recent years, self-healing concrete technology has gradually become a key research focus, aiming to solve various problems that occur in concrete during use and improve its service life and performance. However, most existing technologies are limited to a single repair mechanism, making it difficult to simultaneously meet multiple requirements such as strength recovery, impermeability, and corrosion resistance. Moreover, traditional admixtures have limited protective effects on reinforcing steel and cannot adapt to changes in local environments. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a low-crack, high-corrosion-resistant concrete for wind turbine towers and its preparation method.

[0004] In a first aspect, this application provides a low-crack, high-corrosion-resistant concrete for wind turbine towers. By weight, the raw materials used include the following components: cement, 410-420 parts; mineral powder, 62-67 parts; glass microspheres, 70-75 parts; silica fume, 40-42 parts; basalt gravel, 1050-1150 parts; natural sand, 640-660 parts; an admixture composition, 9.5-10 parts; and water, 120-130 parts. The raw materials used in the admixture composition... The materials include: polycarboxylate superplasticizer, 35-45 parts; self-healing capsule, 4-6 parts; supported Bacillus spores, 2-2.5 parts; corrosion inhibitor complex, 3-5 parts; sodium polyacrylate, 0.3-0.8 parts; polyether defoamer, 0.05-0.15 parts; and water, 40-50 parts. The core material of the self-healing capsule includes acrylic acid and acrylic acid derivatives. The carrier used to prepare the supported Bacillus spores includes calcium lactate. The corrosion inhibitor complex is prepared from aniline and zinc phosphate.

[0005] By adopting the above technical solution, this application incorporates self-healing capsules, supported Bacillus spores, and a corrosion-inhibiting complex into the admixture composition. Specifically, this application utilizes acrylic acid and acrylic acid derivatives as the core material of the self-healing capsules. When microcracks appear in the concrete, the self-healing capsules rupture and release the core material. Upon contact with moisture, a polymerization reaction occurs, rapidly filling the microcracks inside the concrete and restoring structural integrity. The calcium lactate in the supported Bacillus spores serves as a calcium source, providing ionic cross-linking points and enhancing the spore wall stability. Upon contact with water, the Bacillus spores metabolize to produce calcium carbonate precipitate, which blocks the microcracks inside the concrete, improving density and impermeability. The corrosion-inhibiting complex, prepared from aniline and zinc phosphate, remains inert in the alkaline environment of the concrete. When the local pH of the concrete decreases due to carbonation or chloride ion intrusion, the corrosion-inhibiting complex dissociates and releases carbonate ions, forming a passivation film that weakens the corrosion of the reinforcing steel within the concrete.

[0006] Overall, the admixture composition of this application exhibits a synergistic effect among various substances, including polycarboxylate superplasticizer, self-healing capsules, supported Bacillus spores, corrosion inhibitor complex, sodium polyacrylate, and polyether defoamer. When added to concrete, the resulting concrete for wind turbine towers demonstrates excellent strength recovery, high impermeability, and high corrosion resistance. During the concrete pouring and molding process, the number of internal and surface microcracks is significantly reduced, resulting in high internal density and a good appearance. Tests have shown that its water absorption rate is no higher than 1%, its 28-day compressive strength can reach over 102 MPa, its mass loss rate after 200 freeze-thaw cycles is no higher than 0.8 wt%, and its total cracked area per unit area is no higher than 74 mm². 2 / m 2 .

[0007] Preferably, the core material of the self-healing capsule comprises methyl acrylate and butyl acrylate.

[0008] By adopting the above technical solution, this application utilizes methyl acrylate and butyl acrylate as the core material of the self-healing capsule. The blending of the two materials balances the molecular chain length, thus forming a strong and tight bond in the concrete matrix while avoiding excessive brittleness. They can also complex with metal ions in cement hydration products, accelerating the hydration process and improving the final strength of the concrete. Both materials have certain ester group stability and hydrolysis resistance, exhibiting more stable long-term performance in humid environments. Furthermore, methyl acrylate has a lower molecular weight, allowing it to penetrate more smoothly into the microcracks of concrete, resulting in higher bonding strength. Butyl acrylate has better stress adaptability and lower brittleness. The two materials have a good synergistic effect, forming a high-strength micro-region structure that effectively inhibits concrete shrinkage cracking and further optimizes the appearance of the concrete after molding.

[0009] Preferably, when preparing the corrosion inhibitory compound, the weight ratio of aniline to zinc phosphate is 10:(3-5).

[0010] By adopting the above technical solution, this application controls the weight ratio of aniline and zinc phosphate when preparing the corrosion inhibitory compound, thereby regulating the uniformity of polyaniline coating and nucleation behavior, and optimizing the anti-corrosion synergistic mechanism. If the amount of zinc phosphate is too small, aniline will undergo a self-polymerization reaction to generate independent polyaniline particles instead of a composite coating structure, resulting in weakened interfacial bonding and impaired corrosion inhibition ability. If the amount of zinc phosphate is too large, aniline will not be able to completely cover the surface of zinc phosphate, and the exposed zinc phosphate area will weaken the synergistic corrosion inhibition effect of the corrosion inhibitory compound.

[0011] Secondly, this application also provides a method for preparing the aforementioned low-crack, high-corrosion-resistant concrete for wind turbine towers, comprising the following steps: S1. Preparation of self-healing capsules; S2. Preparation of loaded Bacillus spores; S3. Prepare corrosion-inhibiting composites; S4. Mix polycarboxylate superplasticizer, self-healing capsules, supported Bacillus spores, corrosion inhibitor complex, sodium polyacrylate, polyether defoamer and water to obtain an additive composition; S5. Premix cement, sand, gravel, fly ash and mineral powder, add the admixture composition obtained in S4 and water, and stir evenly to obtain low-crack and high-corrosion-resistant concrete.

[0012] By adopting the above technical solution, this application prepares an admixture composition by blending polycarboxylate superplasticizer, self-healing capsules, supported Bacillus spores, corrosion inhibitor complex, sodium polyacrylate, polyether defoamer, and water in specific weight parts. When added to concrete, this composition enables wind turbine tower concrete to possess excellent strength recovery ability, high impermeability, and high corrosion resistance, with a water absorption rate not exceeding 1%, a 28-day compressive strength exceeding 102 MPa, a mass loss rate not exceeding 0.8 wt% after 200 freeze-thaw cycles, and a total crack area per unit area not exceeding 74 mm². 2 / m 2 .

[0013] Preferably, in step S1, the specific steps for preparing the self-healing capsule include: The core material, bridging agent and surfactant were blended in a weight ratio of (8-12):2:1 to obtain the oil phase; tetraethyl orthosilicate was dispersed in water and the pH was adjusted to 9-10 to obtain the aqueous phase; the oil phase and aqueous phase were blended, emulsified, gelled, centrifuged, washed and dried to obtain the self-healing capsule; wherein the weight ratio of methyl acrylate and tetraethyl orthosilicate was (8-12):(30-40).

[0014] By employing the above technical solution, this application obtains an oil phase by blending the core material, bridging agent, and surfactant in a specific weight ratio, disperses tetraethyl orthosilicate in water and adjusts the pH to obtain an aqueous phase, and then blends the oil phase and aqueous phase before preparing a self-healing capsule through emulsification, gelation, and other steps. By controlling the weight ratio of methyl acrylate and tetraethyl orthosilicate, a high-performance self-healing capsule can be obtained. In the specific embodiments of this application, the bridging agent is 3-(trimethoxysilyl)propyl methacrylate, and the surfactant is Span 80. These are merely illustrative examples; those skilled in the art can make reasonable substitutions and adjustments based on actual circumstances. Therefore, this should not be used to limit the scope of protection of this application.

[0015] This application also controls the weight ratio of methyl acrylate and tetraethyl orthosilicate during the preparation of the self-healing capsule, so that the two can exert a better synergistic effect, better form the self-healing capsule structure, improve the performance of the self-healing capsule in concrete, further enhance the impermeability and strength of concrete, more effectively inhibit concrete shrinkage cracking, and improve the appearance quality.

[0016] Preferably, in step S2, the specific steps for preparing the loaded Bacillus spores include: Bacillus substrate was cultured to the spore stage, and Bacillus spores were collected by centrifugation. The Bacillus spores were then resuspended in water to obtain a concentration of 0.9 × 10⁻⁶. 9 CFU / mL -1.1×10 9 The spore suspension was prepared at CFU / mL, and then the carrier was added to the spore suspension at an amount of 9-12% (w / v). The mixture was stirred evenly at 20-30℃ and spray-dried to constant weight under the conditions of inlet air temperature of 150-160℃, outlet air temperature of 75-85℃, atomization pressure of 0.3-0.35MPa, and flow rate of 8-12mL / min to obtain loaded Bacillus spores.

[0017] Preferably, the concentration of the spore suspension is 1×10⁻⁶. 9 CFU / mL, with a carrier addition of 10.5% (w / v).

[0018] By adopting the above technical solution, this application adds the carrier to a spore suspension of a specific concentration, stirs it evenly at a suitable temperature, and then spray-dries it to a constant weight under specific conditions such as inlet air temperature, outlet air temperature, atomization pressure, and flow rate. This allows calcium lactate, as a calcium source, to provide ion cross-linking points, enhance the spore wall stability of Bacillus spores, and produce calcium carbonate precipitate after encountering water, which blocks microcracks inside the concrete, improves the density and impermeability of the concrete, and optimizes the appearance of the concrete. The preparation method of this application is suitable for industrial production, taking into account both high spore survival rate and low process complexity.

[0019] Preferably, when the carrier is added to the spore suspension, inulin and nano-silica are also added, and the weight ratio of the carrier, inulin and nano-silica is 3:2:(0.3-0.4).

[0020] By adopting the above technical solution, this application utilizes a compound of calcium lactate, inulin, and nano silica in a weight ratio of 3:2:(0.3-0.4). Calcium lactate, as a calcium source, provides ionic cross-linking points, enhancing the spore wall stability of Bacillus spores. Inulin, as a polysaccharide protectant, reduces drying damage, improves thermal stability, and lowers the possibility of Bacillus spores becoming inactive under dry conditions and at elevated temperatures. Nano silica significantly improves fluidity. When these three components are mixed with the spore suspension, a more stable powdered loaded Bacillus spore can be obtained.

[0021] Preferably, in step S1, the specific steps for preparing the corrosion-inhibiting compound include: Zinc phosphate was placed in an acidic solution with pH 1-3, stirred, cooled to 0-5℃, aniline was added, stirred, and an oxidant was added while maintaining the temperature for 6-12 hours. The mixture was then filtered, washed, and dried to obtain the corrosion inhibitor complex.

[0022] By adopting the above technical solution, this application places zinc phosphate in an acidic solution to fully disperse and ionize it to a certain extent, providing suitable conditions for the subsequent reaction with aniline. Cooling slows down the reaction rate, making the combination of aniline and zinc phosphate more complete and stable, avoiding uneven products caused by excessively fast reaction. While keeping the temperature, an oxidant is added to ensure the reaction proceeds fully, allowing aniline and zinc phosphate to form a stable composite structure, thereby preparing a corrosion-inhibiting composite with good corrosion inhibition properties. It can remain inert in the alkaline environment of concrete. When the local pH decreases due to carbonization or chloride ion intrusion, it dissociates and releases phosphate ions to form a passivation film to inhibit steel corrosion.

[0023] In summary, this application has the following beneficial technical effects: 1. The concrete of this application includes a variety of substances that enhance crack resistance and corrosion resistance. Among them, the self-healing capsule can release the core material through cracking, which polymerizes and fills the micro-cracks in the concrete upon contact with water, restoring structural integrity and strength, and solving the problem of strength reduction caused by micro-cracks in concrete. The loaded Bacillus spores metabolize upon contact with water to produce calcium carbonate precipitate, which blocks the micro-cracks inside the concrete, improves density and impermeability, and solves the problem of concrete durability deterioration. The corrosion inhibitory compound dissociates and releases phosphate ions when the local pH decreases to form a passivation film, inhibiting steel corrosion, adapting to local environmental changes, and solving the problem of limited protection effect of traditional admixtures on steel bars. 2. The concrete obtained in this application possesses excellent strength recovery ability, high impermeability, and high corrosion resistance. During the concrete pouring and molding process, the number of internal and surface microcracks is significantly reduced, resulting in high internal density and a good appearance. Tests have shown that its water absorption rate is no higher than 1%, its 28-day compressive strength can reach over 102 MPa, its mass loss rate after 200 freeze-thaw cycles is no higher than 0.8 wt%, and its total cracked area per unit area is no higher than 74 mm. 2 / m 2 . Detailed Implementation

[0024] Material source The cement was purchased from Tianjin Jinyu Zhenxing Environmental Protection Technology Co., Ltd., and the type was PO 52.5. Basalt pebble, with a particle size of 5-20mm, continuously graded; Natural sand, fineness modulus 2.9, mud content ≤1.0%; Mineral powder, purchased from Jining Hengzhi New Building Materials Co., Ltd., grade S95, 7d activity index ≥75%; Glass microspheres, 150 mesh, purchased from Lingshou County Zemin Mineral Products Processing Plant; Silica fume, purchased from Lingshou County Baixin New Material Technology Co., Ltd., 1250 mesh; Polycarboxylate superplasticizer, purchased from Beijing Jinyu Cement Energy Saving Technology Co., Ltd., model number JY-TS-1; Bacillus substrate was purchased from Anhui Zhuantai Biotechnology Co., Ltd. The polyether defoamer was purchased from Beijing Kemete Technology Development Co., Ltd., model number TEGO XP22063.

[0025] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0026] Example 1.1 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers includes the following steps: S1. Preparation of self-healing capsules: 80g of core material (methyl methacrylate), 20g of bridging agent and 10g of Span 80 were mixed to obtain an oil phase. 400g of tetraethyl orthosilicate was dissolved in 2L of water and the pH was adjusted to 9 to obtain an aqueous phase. All the oil phase was added dropwise to the aqueous phase and sheared and emulsified at 10000rpm for 20min to form a microemulsion. The pH was then adjusted to 3 and stirred at 60℃ for 4h. The capsules were then separated by centrifugation, washed with alcohol, and vacuum dried at 60℃ to obtain self-healing capsules. S2. Preparation of loaded Bacillus spores: Bacillus was cultured to the spore stage, and the spores were collected by centrifugation. The spores were then resuspended in water to obtain a concentration of 0.9 × 10⁻⁶ spores per liter. 9 The spore suspension was prepared at CFU / mL, and then 120g of calcium lactate was added to the spore suspension. The mixture was stirred evenly at 30°C and spray-dried to constant weight under the conditions of inlet air temperature of 150°C, outlet air temperature of 75°C, atomization pressure of 0.35MPa and flow rate of 8mL / min to obtain loaded Bacillus spores. S3. Preparation of corrosion inhibitor complex: 30g of zinc phosphate was placed in an acidic solution with pH=1 and ultrasonically stirred for 30min. Then the temperature was lowered to 0℃, 100g of aniline monomer was added, and after stirring for 30min, an equimolar amount of APS was added dropwise. The reaction was continued at 0℃ for 6h. After filtration and washing with alcohol, the mixture was vacuum dried at 60℃ to constant weight to obtain the corrosion inhibitor complex. S4. Mix 450g of polycarboxylate superplasticizer, 40g of self-healing capsules, 25g of loaded Bacillus spores, 30g of corrosion inhibitor complex, 8g of sodium polyacrylate, 0.5g of polyether defoamer and 500mL of water to obtain an additive composition. S4. Weigh 41kg of cement, 67kg of mineral powder, 7kg of glass microspheres, 4.2kg of silica fume, 105kg of basalt gravel, 66kg of natural sand, 0.95kg of the admixture composition obtained in S4, and 13L of water, and mix them evenly to obtain low-crack, high-corrosion-resistant concrete.

[0027] Example 1.2 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers includes the following steps: S1. Preparation of self-healing capsules: 120g core material (methyl methacrylate), 20g bridging agent and 10g Span 80 were mixed to obtain an oil phase. 300g tetraethyl orthosilicate was dissolved in 1.5L water and the pH was adjusted to 10 to obtain an aqueous phase. All the oil phase was added dropwise to the aqueous phase and sheared and emulsified at 10000rpm for 20min to form a microemulsion. The pH was then adjusted to 3 and stirred at 60℃ for 4h. The capsules were then separated by centrifugation, washed with alcohol, and vacuum dried at 60℃ to obtain self-healing capsules. S2. Preparation of loaded Bacillus spores: Bacillus was cultured to the spore stage, and the spores were collected by centrifugation. The spores were then resuspended in water to obtain a concentration of 1.1 × 10⁻⁶ spores per liter. 9The spore suspension was prepared at CFU / mL, and then 90g of calcium lactate was added to the spore suspension. The mixture was stirred evenly at 20°C and spray-dried to constant weight under the conditions of inlet air temperature of 160°C, outlet air temperature of 85°C, atomization pressure of 0.3MPa and flow rate of 12mL / min to obtain loaded Bacillus spores. S3. Preparation of corrosion inhibitor complex: 50g of zinc phosphate was placed in an acidic solution with pH=3 and ultrasonically stirred for 30min. Then the temperature was lowered to 0℃, 100g of aniline monomer was added, and after stirring for 30min, an equimolar amount of APS was added dropwise. The reaction was continued at 0℃ for 12h. After filtration and washing with alcohol, the mixture was vacuum dried at 60℃ to constant weight to obtain the corrosion inhibitor complex. S4. Mix 350g of polycarboxylate superplasticizer, 60g of self-healing capsules, 20g of loaded Bacillus spores, 50g of corrosion inhibitor complex, 3g of sodium polyacrylate, 1.5g of polyether defoamer and 400mL of water to obtain an additive composition. S4. Weigh 42kg of cement, 62kg of mineral powder, 7.5kg of glass microspheres, 4kg of silica fume, 115kg of basalt gravel, 64kg of natural sand, 1kg of the admixture composition obtained in S4, and 12L of water, and mix them evenly to obtain low-crack, high-corrosion-resistant concrete.

[0028] Example 1.3 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers includes the following steps: S1. Preparation of self-healing capsules: 100g core material (methyl methacrylate), 20g bridging agent and 10g Span 80 were mixed to obtain an oil phase. 350g tetraethyl orthosilicate was dissolved in 1.75L of water and the pH was adjusted to 9.5 to obtain an aqueous phase. All the oil phase was added dropwise to the aqueous phase and sheared and emulsified at 10000rpm for 20min to form a microemulsion. The pH was then adjusted to 3 and stirred at 60℃ for 4h. The capsules were then separated by centrifugation, washed with alcohol, and vacuum dried at 60℃ to obtain self-healing capsules. S2. Preparation of loaded Bacillus spores: Bacillus was cultured to the spore stage, and the spores were collected by centrifugation. The spores were then resuspended in water to obtain a concentration of 1×10⁻⁶ spores per liter. 9 The spore suspension was prepared at CFU / mL, and then 105g of calcium lactate was added to the spore suspension. The mixture was stirred evenly at 25°C and spray-dried to constant weight under the conditions of inlet air temperature of 155°C, outlet air temperature of 80°C, atomization pressure of 0.32MPa and flow rate of 10mL / min to obtain loaded Bacillus spores. S3. Preparation of corrosion inhibitor complex: 40g of zinc phosphate was placed in an acidic solution with pH=2 and ultrasonically stirred for 30min. Then the temperature was lowered to 0℃, 100g of aniline monomer was added, and after stirring for 30min, an equimolar amount of APS was added dropwise. The reaction was continued at 0℃ for 9h. After filtration and washing with alcohol, the mixture was vacuum dried at 60℃ to constant weight to obtain the corrosion inhibitor complex. S4. Mix 400g of polycarboxylate superplasticizer, 50g of self-healing capsules, 22.5g of loaded Bacillus spores, 40g of corrosion inhibitor complex, 5.5g of sodium polyacrylate, 1g of polyether defoamer and 450mL of water to obtain an additive composition. S4. Weigh 41.6 kg of cement, 65 kg of mineral powder, 7.3 kg of glass microspheres, 4.1 kg of silica fume, 110 kg of basalt gravel, 65 kg of natural sand, 0.97 kg of the admixture composition obtained in S4, and 12.5 L of water, and mix them evenly to obtain low-crack, high-corrosion-resistant concrete.

[0029] Example 2.1 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 100g of methyl acrylate, and the rest is the same as in Example 1.3.

[0030] Example 2.2 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 100g of butyl acrylate, and the rest is the same as in Example 1.3.

[0031] Example 2.3 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 100g of hydroxyethyl acrylate, and the rest is the same as in Example 1.3.

[0032] Example 2.4 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 50g of methyl acrylate and 50g of butyl acrylate, while the rest are the same as in Example 1.3.

[0033] Example 2.5 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 50g of methyl methacrylate and 50g of butyl acrylate, while the rest are the same as in Example 1.3.

[0034] Example 2.6 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 50g of methyl acrylate and 50g of hydroxyethyl acrylate, while the rest are the same as in Example 1.3.

[0035] Example 2.7 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 30g of methyl acrylate and 70g of butyl acrylate, while the rest are the same as in Example 1.3.

[0036] Example 2.8 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S1, the core material is 70g of methyl acrylate and 30g of butyl acrylate, while the rest are the same as in Example 1.3.

[0037] Example 3.1 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S2, 70g of inulin and 10.5g of nano-silica are added when calcium lactate is added to the spore suspension; otherwise, the method is the same as in Example 1.3.

[0038] Example 3.2 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S2, 70g of inulin and 14g of nano-silica are added when calcium lactate is added to the spore suspension; otherwise, the method is the same as in Example 1.3.

[0039] Example 4.1 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S3, the amount of zinc phosphate used is 20g, while the rest are the same as in Example 1.3.

[0040] Example 4.2 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S3, the amount of zinc phosphate used is 40g, while the rest are the same as in Example 1.3.

[0041] Example 4.3 A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers differs from Example 1.3 in that: in S3, the amount of zinc phosphate used is 60g, while the rest are the same as in Example 1.3.

[0042] Comparative Example 1.1 The difference from Example 1.3 is that in S4, the self-repair capsule is removed, and everything else is the same as in Example 1.3.

[0043] Comparative Example 1.2 The difference from Example 1.3 is that in S4, the loaded Bacillus spores are removed, and the rest is the same as in Example 1.3.

[0044] Comparative Example 1.3 The difference from Example 1.3 is that in S4, the corrosion inhibitor complex is removed, and everything else is the same as in Example 1.3.

[0045] Comparative Example 2.1 The difference from Example 1.3 is that in S4, the self-repairing capsule and the loaded Bacillus spores are removed, while the rest are the same as in Example 1.3.

[0046] Comparative Example 2.2 The difference from Example 1.3 is that in S4, the corrosion inhibitory complex and the loaded Bacillus spores are removed, while the rest are the same as in Example 1.3.

[0047] Comparative Example 2.3 The difference from Example 1.3 is that in S4, the corrosion inhibitory compound and the self-healing capsule are removed, while the rest are the same as in Example 1.3.

[0048] Performance testing The low-crack, high-corrosion-resistant concrete obtained in the examples and comparative examples was poured into a steel reinforcement cage (the steel reinforcement content was 3% of the total weight of the low-crack, high-corrosion-resistant concrete), and concrete specimens were prepared for the following tests: 1. Water absorption rate test: Take a 100mm×100mm×100mm concrete test block, dry it at 105℃ for 72 hours, weigh it and record it as m1. Then immerse the test block completely in water until the mass is constant. After taking it out, wipe off the surface moisture and weigh it again and record it as m2. The water absorption rate calculation formula is: Water absorption rate = (m2-m1) / m1×100%; 2. Compressive strength test: The 28-day compressive strength of concrete specimens with dimensions of 150mm×150mm×150mm was tested using a pressure testing machine, and the operation was carried out in accordance with GB / T 50081-2016 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete"; 3. Freeze-thaw cycle test: The freeze-thaw cycle test was conducted according to GB / T 50082-2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete". Concrete specimens with dimensions of 100mm×100mm×400mm were placed in a temperature range of -18℃ to 4℃ and cyclically tested for 200 cycles. After the cycle, the mass loss rate was measured. Mass loss rate = (initial mass - mass after cycle) / initial mass × 100%; 4. Crack resistance test: The crack resistance of concrete was determined by the "crack resistance plate test". The test time point was 28 days after the concrete block was formed. The test results were expressed as the total crack area per unit area calculated.

[0049] Table 1 Data Record Table

[0050] Data Analysis: As shown in Table 1, the water absorption rate of the low-crack, high-corrosion-resistant concrete obtained in Examples 1.1-1.3 was reduced to 0.82-0.87%, the 28-day compressive strength was increased to 103.5-105.3 MPa, and the total crack area per unit area was reduced to 59-63 mm. 2 / m 2 This reduces the freeze-thaw cycle mass loss rate to 0.67-0.72%. It is evident that the polycarboxylate superplasticizer, self-healing capsules, supported Bacillus spores, corrosion inhibitor, sodium polyacrylate, and polyether defoamer in the admixture composition of this application fully exert their synergistic effect. When added to concrete, the concrete used in wind turbine towers exhibits excellent strength recovery, high impermeability, and high corrosion resistance. During the concrete pouring and molding process, the number of internal and surface microcracks is greatly reduced, resulting in high internal density and a good appearance.

[0051] In Examples 2.1-2.8, this application changed the raw materials of the core material. The results showed that the low-crack, high-corrosion-resistant concrete of Examples 2.4 and 2.7-2.8 had lower water absorption, higher 28-day compressive strength, and higher total crack area per unit area. It can be seen that this application uses methyl acrylate and butyl acrylate as the core material of the self-healing capsule. The blending of the two balances the molecular chain length, so it can form a strong and tight bond in the concrete matrix, avoid excessive brittleness, and complex with metal ions in cement hydration products, accelerating the hydration process and improving the final strength of concrete. Both have certain ester group stability and hydrolysis resistance, and have more stable long-term performance in humid environments. In addition, methyl acrylate has a lower molecular weight, which can penetrate into the micro-cracks of concrete more smoothly and has higher bonding strength. Butyl acrylate has better stress adaptability and lower brittleness. The two have a good synergistic effect and can form a high-strength micro-zone structure, effectively inhibiting concrete shrinkage cracking.

[0052] In Examples 3.1-3.2, this application also added inulin and nano-silica when adding calcium lactate to the spore suspension. The results showed that the water absorption rate of the low-crack, high-corrosion-resistant concrete was reduced to below 0.74%. It can be seen that inulin can act as a polysaccharide protectant to reduce drying damage, improve thermal stability, and reduce the possibility of Bacillus spores becoming inactive in dry environments and at elevated temperatures. Nano-silica significantly improves fluidity. The combination of calcium lactate, inulin, and nano-silica with the spore suspension can produce more stable powdered loaded Bacillus spores.

[0053] In Examples 4.1-4.3, this application adjusted the amount of zinc phosphate. The water absorption rate of the low-crack, high-corrosion-resistant concrete obtained in Examples 4.1 and 4.3 increased, while the 28-day compressive strength and the total crack area per unit area decreased. It can be seen that this application controlled the weight ratio of aniline and zinc phosphate when preparing the corrosion-inhibiting composite, thereby regulating the uniformity of polyaniline coating and nucleation behavior, and optimizing the anti-corrosion synergistic mechanism. If the amount of zinc phosphate is too small, aniline will undergo a self-polymerization reaction to generate independent polyaniline particles instead of a composite coating structure, resulting in weakened interfacial bonding and impaired corrosion inhibition ability. If the amount of zinc phosphate is too large, aniline will not be able to completely cover the surface of zinc phosphate, and the exposed zinc phosphate area will weaken the synergistic corrosion inhibition effect of the corrosion-inhibiting composite.

[0054] In Comparative Examples 1.1-2.3, the composition of the admixture composition was adjusted in this application. The results showed that the water absorption rate, mass loss rate, and total crack area per unit area of ​​the low-crack, high-corrosion-resistant concrete increased dramatically, while the 28-day compressive strength decreased significantly. It can be seen that the self-healing capsule will rupture and release the core material when microcracks occur in the concrete. After contact with water, a polymerization reaction occurs, which quickly fills the microcracks inside the concrete and restores the integrity of the structure. The calcium lactate in the loaded Bacillus spores can provide ionic cross-linking points as a calcium source, which enhances the stability of the spore wall of Bacillus spores. After Bacillus spores come into contact with water, they metabolize to produce calcium carbonate precipitate, which blocks the microcracks inside the concrete and improves the density and impermeability. The corrosion inhibitor complex prepared by aniline and zinc phosphate can remain inert in the alkaline environment of concrete. When the local pH of the concrete decreases due to carbonation or chloride ion intrusion, the corrosion inhibitor complex dissociates and releases carbonate ions to form a passivation film, thereby weakening the degree of corrosion of the steel reinforcement in the concrete.

[0055] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A low-crack, high-corrosion-resistant concrete for wind turbine towers, characterized in that, The raw materials used, by weight, include the following components: Cement, 410-420 parts; mineral powder, 62-67 parts; glass microspheres, 70-75 parts; Silica fume, 40-42 parts; basalt gravel, 1050-1150 parts; natural sand, 640-660 parts; Additive composition, 9.5-10 parts; Water, 120-130 parts; the raw materials used in the additive composition include: polycarboxylate superplasticizer, 35-45 parts; self-healing capsule, 4-6 parts; supported Bacillus spores, 2-2.5 parts; corrosion inhibitor complex, 3-5 parts; sodium polyacrylate, 0.3-0.8 parts; polyether defoamer, 0.05-0.15 parts; water, 40-50 parts; the core material of the self-healing capsule includes acrylic acid and acrylic acid derivatives, the carrier for preparing the supported Bacillus spores includes calcium lactate, and the corrosion inhibitor complex is prepared from aniline and zinc phosphate; The specific steps for preparing the corrosion inhibitory compound include: Zinc phosphate was placed in an acidic solution with pH 1-3, stirred, cooled to 0-5℃, aniline was added, stirred, and an oxidant was added while maintaining the temperature for 6-12 hours. The mixture was then filtered, washed, and dried to obtain the corrosion inhibitor complex.

2. The low-crack, high-corrosion-resistant concrete for wind turbine towers according to claim 1, characterized in that, The core material of the self-healing capsule includes methyl acrylate and butyl acrylate.

3. The low-crack, high-corrosion-resistant concrete for wind turbine towers according to claim 1, characterized in that, When preparing the corrosion inhibitory compound, the weight ratio of aniline to zinc phosphate is 10:(3-5).

4. A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Preparation of self-healing capsules; S2. Preparation of loaded Bacillus spores; S3. Prepare corrosion-inhibiting composites; S4. Mix polycarboxylate superplasticizer, self-healing capsules, supported Bacillus spores, corrosion inhibitor complex, sodium polyacrylate, polyether defoamer and water to obtain an additive composition; S5. Mix cement, mineral powder, glass microspheres, silica fume, basalt stones and natural sand, add the admixture composition obtained in S4 and water, and stir evenly to obtain low-crack and high-corrosion-resistant concrete.

5. The method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers according to claim 4, characterized in that, In step S1, the specific steps for preparing the self-healing capsule include: The core material, bridging agent and surfactant were blended in a weight ratio of (8-12):2:1 to obtain the oil phase; tetraethyl orthosilicate was dispersed in water and the pH was adjusted to 9-10 to obtain the aqueous phase; the oil phase and aqueous phase were blended, emulsified, gelled, centrifuged, washed and dried to obtain the self-healing capsule; wherein the weight ratio of methyl acrylate and tetraethyl orthosilicate was (8-12):(30-40).

6. The method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers according to claim 4, characterized in that, In step S2, the specific steps for preparing the loaded Bacillus spores include: Bacillus substrate was cultured to the spore stage, and Bacillus spores were collected by centrifugation. The Bacillus spores were then resuspended in water to obtain a concentration of 0.9 × 10⁻⁶. 9 CFU / mL -1.1×10 9 The spore suspension was prepared at CFU / mL, and then the carrier was added to the spore suspension at an amount of 9-12% (w / v). The mixture was stirred evenly at 20-30℃ and spray-dried to constant weight under the conditions of inlet air temperature of 150-160℃, outlet air temperature of 75-85℃, atomization pressure of 0.3-0.35MPa, and flow rate of 8-12mL / min to obtain loaded Bacillus spores.

7. The method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers according to claim 6, characterized in that, The concentration of the spore suspension was 1×10⁻⁶. 9 CFU / mL, with a carrier addition of 10.5% (w / v).

8. A method for preparing low-crack, high-corrosion-resistant concrete for wind turbine towers according to claim 6, characterized in that, When the carrier is added to the spore suspension, inulin and nano-silica are also added, and the weight ratio of the carrier, inulin and nano-silica is 3:2:(0.3-0.4).

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