Autoclaved aerated concrete slab and preparation method thereof

Abstract

The invention relates to the technical field of autoclaved aerated concrete slabs, in particular to an autoclaved aerated concrete slab and a preparation method thereof, and the autoclaved aerated concrete slab comprises the following raw materials by mass: 110-120 parts of lime; 140 to 150 parts of cement; 50 to 55 parts of desulfurized gypsum; 9-11 parts of aluminum powder; 8-15 parts of functional particles; 0.15 to 0.25 part of a polycarboxylic acid type water reducing agent; 0.08 to 0.12 part of a citric acid retarder; 0.08 to 0.12 part of a rosin thermopolymer air entraining agent; the hardness of the softened water is lower than 50mg / L. Through innovative design of functional particles and regulation and control of a whole-flow process, collaborative improvement of light weight, high strength, excellent durability and process stability of the autoclaved aerated concrete plate is realized; the problems that strength and density of a traditional product are difficult to balance, durability is insufficient due to weak interface bonding, and process fluctuation is caused by mismatching of gas forming and condensation rhythms are solved.

Description

Technical Field

[0001] This invention relates to the field of autoclaved aerated concrete (AAC) panels, and more specifically, to an AAC panel and its preparation method. Background Technology

[0002] Autoclaved aerated concrete (AAC) panels, as a lightweight, heat-insulating, and environmentally friendly new type of wall material, are widely used in the construction industry. However, performance improvement and process optimization remain key research areas in the industry. Traditional AAC production often suffers from a difficulty in balancing strength and density. Pursuing lightweight results in insufficient strength, while increasing strength increases material density, affecting insulation performance. Simultaneously, the material's durability (such as frost resistance and impermeability) is significantly influenced by interface structure and pore distribution. The interface transition zone between the cementitious system and aggregates is often a weak point, prone to structural damage due to stress concentration. Furthermore, the matching of aluminum powder gas generation rate and slurry setting speed during production is difficult to control precisely, often leading to product quality fluctuations due to uneven gas generation, bubble merging, or mold collapse, resulting in poor process stability. Additionally, while the high-value utilization of industrial solid waste (such as steelmaking slag) aligns with the concept of green development, the complex composition and low activity of slag mean that direct incorporation can negatively impact material performance, limiting its application in high-performance AAC. These technological bottlenecks have prompted the industry to explore ways to achieve a synergistic improvement in the lightweight, high-strength, and durable properties of autoclaved aerated concrete (AAC) panels, as well as stable processes and efficient utilization of solid waste, through component innovation and process optimization.

[0003] Existing technology describes an autoclaved aerated concrete (AAC) slab and its preparation method. The AAC slab is produced by combining lime, cement, mining waste, desulfurized gypsum, aluminum powder, and vermiculite powder in a specific ratio, followed by steps including preparing a cementitious slurry, diluting a gas-generating agent, producing a mixed cementitious foam concrete, casting, cutting the slab, and autoclaving. The AAC slab produced by this method exhibits good sound insulation. However, the lack of precise matching and control between the aluminum powder gas generation rate and the slurry setting speed may lead to uneven bubble distribution, affecting the slab's mechanical properties and appearance. Furthermore, while the inclusion of mining waste achieves comprehensive resource utilization, the lack of modification treatment may weaken the overall strength and durability of the concrete slab due to insufficient waste activity.

[0004] Existing technology describes the preparation of a solid waste-based autoclaved aerated concrete (AAC) slab. The addition of modified basalt fiber and modified copper tailings significantly improves the crack resistance and compressive strength of the concrete slab. Simultaneously, the use of 2-phosphonobutane-1,2,4-tricarboxylic acid and ammonium dodecyl sulfate inhibits the hydration reaction and absorbs some of the heat of hydration, thereby enhancing the thermal performance of the concrete slab. However, in this technical solution, the preparation process of the modified copper tailings is relatively complex, increasing production costs and process difficulty. Furthermore, a high dosage of modified basalt fiber may reduce the workability of the concrete slurry, affecting construction performance. In addition, this technical solution does not fully consider the coordination between aluminum powder gas generation and slurry coagulation, which may lead to uneven pore structure, thus affecting the thermal insulation and mechanical properties of the slab.

[0005] The above problems indicate that existing autoclaved aerated concrete (AAC) panels and their preparation methods still have certain shortcomings in terms of the compatibility of aluminum powder gas generation and slurry coagulation, the modification and treatment of industrial solid waste, process stability, and overall performance optimization. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides an autoclaved aerated concrete (AAC) panel and its preparation method. Through innovative design of functional particles and full-process process control, it achieves a synergistic improvement in the lightweight, high-strength, and durable properties of the AAC panel, as well as stable processing. This solves problems such as difficulty in balancing strength and density, insufficient durability due to weak interfacial bonding, and process fluctuations caused by mismatch between gas generation and condensation rhythms in traditional products.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 110-120 parts lime; 140-150 parts cement; 50-55 parts of desulfurized gypsum; 9-11 parts aluminum powder; 8-15 parts of functional particles; 0.15-0.25 parts of polycarboxylate superplasticizer, wherein the solid content of the polycarboxylate superplasticizer is 25%; Citric acid retarder 0.08-0.12 parts, wherein the purity of the citric acid retarder is greater than 99%; Rosin thermal polymer air-entraining agent 0.08-0.12 parts; 65-75 parts of softened water, wherein the hardness of the softened water is less than 50 mg / L; The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 1.5-2.5% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​formed by grinding and granulating converter slag or electric furnace slag, and its chemical composition, by mass, includes 30-60 parts CaO, 10-25 parts SiO2, 5-15 parts Al2O3, 3-12 parts MgO, and 10-20 parts Fe2O3.

[0008] This solution achieves system optimization from the microstructure to the macroscopic properties of materials through the synergistic effect of multiple components and the composite design of functional particles. Its core mechanism lies in constructing a structural framework based on a cementitious system, forming a lightweight porous structure through aluminum powder gas generation, combined with surface modification and interface control of functional particles, and precise control of process performance by admixtures, ultimately achieving a comprehensive improvement in mechanical properties, process stability, and durability. Specifically, the cementitious system composed of lime, cement, and desulfurized gypsum generates hydrated calcium silicate gel, hydrogen CaO, and ettringite during the hydration reaction, forming a continuous structural framework. The desulfurized gypsum also acts as a retarder, delaying setting time and providing a stable process window for aluminum powder gas generation. Aluminum powder, acting as a gas generator, reacts with water to generate hydrogen gas, forming numerous microbubbles in the slurry. The silicone polyether surfactant loaded on the surface of the functional particles inhibits bubble coalescence by reducing the surface tension of the slurry and forms a stable film layer on the bubble surface, ensuring uniform bubble distribution and improving slurry stability.

[0009] Functional particles, with steelmaking furnace ash matrix as the core, rely on precise control of their chemical composition: CaO, as the active component, provides calcium ions to participate in the hydration reaction of the cementitious system, generating CSH gel and regulating the alkalinity of the slurry—too low a content will not provide enough calcium ions, leading to insufficient cementitious reaction and inadequate structural strength; too high a content will damage the passivation film on the surface of aluminum powder due to excessive alkalinity (pH>13), accelerating the reaction rate of aluminum powder and causing uneven gas generation or mold collapse. SiO2 mainly comes from silicate minerals in furnace ash. Its active SiO2 can react with cement hydration products CH to generate CSH gel, filling pores and enhancing interfacial adhesion—too low a content will result in insufficient porosity due to insufficient porosity; too high a content will increase the viscosity of the slurry, hindering the dispersion of aluminum powder and the uniform distribution of bubbles. Alumina also participates in the pozzolanic reaction to form calcium aluminate hydrate (CAH), which hydrates faster than CSH, accelerating early strength development. Simultaneously, the presence of alumina buffers the alkalinity of the slurry; aluminum ions combine with hydroxide ions to form complexes, preventing excessive activation of aluminum powder due to localized high alkalinity. MgO, as an auxiliary active component, produces MSH gel, a hydration product with late-stage strength growth characteristics, compensating for the insufficient early strength of silicate cement. However, when its content is too high (>12%), the hydrogen MgO generated during MgO hydration can cause cracking of the green body due to volume expansion (approximately 2.4 times), thus requiring strict control of the upper limit. Although Fe2O3 is an inert component, its iron ions can catalyze cement hydration reactions (e.g., accelerating the hydration rate of C3S) and regulate the bulk density of the ash. Fe2O3 has a high density; excessive amounts can increase the bulk density of the ash matrix, affecting the dispersibility of functional particles. Therefore, a balance between catalytic effect and density control is needed within a range of 10-30 parts.

[0010] The moisture content (≤5%) of the functional particles is achieved by controlling the dryness of the steelmaking furnace ash matrix. The low moisture content avoids the interference of moisture on the water-ash ratio of the cementitious system, ensuring the matching of slurry fluidity and aluminum powder gas generation rate. The surface-loaded silicone polyether surfactant acts on the particle surface through physical adsorption and chemical bonding. On the one hand, it enhances the interfacial adhesion between the particles and the cementitious system and reduces the weak links in the interfacial transition zone. On the other hand, it regulates the rheological properties of the slurry and optimizes the synergistic rhythm of gas generation and coagulation. Polycarboxylate superplasticizers reduce the water-cement ratio and improve slurry fluidity by adsorbing onto the surface of cementitious material particles, ensuring uniform dispersion of all components. Citric acid retarder slows down the hydration rate of tricalcium aluminate by complexing aluminum ions in cement, matching the gas generation rate of aluminum powder and extending the workable time. Rosin thermal polymer air-entraining agent assists in generating uniform microbubbles through the foaming and stabilizing effects of molecular chains, further optimizing the pore structure. Softened water (hardness <50mg / L) prevents calcium and magnesium ions from reacting with sulfate and carbonate ions in cementitious materials to form precipitates, thus interfering with the hydration process.

[0011] Through the synergistic effect of the components, this solution can achieve lightweight and high-strength mechanical properties, functional particle reinforcement and uniform bubbles to reduce stress concentration, stable process performance and excellent durability, while demonstrating environmental advantages through the resource utilization of steelmaking furnace ash.

[0012] Preferably, the steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​350-400 m². 2 After being granulated, the particle size is 0.5-2.0 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 30-50%.

[0013] Preferably, the method for preparing the functional particles includes: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​350-400 m². 2 / kg, to obtain steelmaking furnace ash powder; Granulation and molding: Add 8-12% of the mass of cement and 10-15% of the mass of water to the steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw material particles with a particle size of 0.5-2.0mm. Curing and solidification: The raw material particles are cured at a temperature of 24-26℃ and a relative humidity of 95-100% for 48-72 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Place the steelmaking furnace ash matrix particles in a rotary drum coating machine and spray a silicone polyether emulsion with a solid content of 40-50%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 1.5-2.5% of the matrix particle mass, and the inlet air temperature is 55-65℃. Curing treatment: After spraying, the particles are cured in hot air circulation at 78-82℃ for 1.5-2.0 hours to obtain functional particles.

[0014] The mechanism of this solution lies in enhancing the activity of furnace ash through pretreatment, ensuring particle morphology uniformity through granulation, strengthening the matrix structure through curing and solidification, and improving interfacial performance through surface loading, ultimately achieving synergistic effects between functional particles and the cementitious system. Specifically, in the pretreatment of steelmaking furnace ash, converter slag or electric arc furnace slag is ground to a specific surface area of ​​350-400 m². 2 / kg, through mechanical grinding, the coarse particle structure of the original slag is broken down, increasing the specific surface area to expose more active sites and enhancing its reactivity with the hydration products of the cementitious system; during granulation, 8-12% cement and 10-15% water are added to the ash powder to control the appropriate humidity, and after mixing, it is extruded and granulated to form raw meal particles of 0.5-2.0mm. The addition of cement not only binds the dispersed ash powder into particles with a certain mechanical strength, but also participates in the subsequent hydration reaction through its own cementitious activity, while the 10-15% water content can ensure that To ensure the plasticity of the granules while avoiding excessive moisture leading to high porosity within the raw meal granules; the curing stage is carried out at 24-26℃ and 95-100% relative humidity for 48-72 hours. This temperature and humidity condition is close to the optimal environment for cement hydration, ensuring that the cement in the raw meal granules is fully hydrated to generate hydrated calcium silicate gel and hydrogen CaO, forming a stable matrix structure. This avoids insufficient curing time (<48 hours) resulting in incomplete hydration and low matrix strength, or excessive curing time (>72 hours) leading to particle drying shrinkage and cracking; surface activity The coating agent is applied using a rotary drum coating machine, spraying a silicone polyether emulsion with a solid content of 40-50% at a rate of 1.5-2.5% dry matter. The rotation of the drum ensures uniform tumbling of the particles. Combined with an inlet air temperature of 55-65℃ (which prevents the emulsion from drying and forming a skin due to excessively low temperature, and also prevents it from breaking down due to excessively high temperature), a continuous and uniform coating layer of silicone polyether is formed on the particle surface. This coating layer reduces the interfacial tension between the particle surface and the gelling slurry, enhancing the wettability of the particles and the slurry. Furthermore, the silicone polyether... Long-chain molecules can penetrate into the micropores on the matrix surface, forming a dual effect of mechanical intercalation and chemical bonding, thus enhancing interfacial adhesion strength. The curing treatment is carried out under hot air circulation at 78-82℃ for 1.5-2.0 hours. Appropriately increasing the temperature accelerates the diffusion and cross-linking reaction of silicone polyether molecules, promoting the transformation of the coating layer from "physical adsorption" to "chemical film formation," resulting in a denser and more stable functional film. Simultaneously, it avoids excessively high temperatures (>85℃) causing the silicone polyether to decompose and lose surface activity, or excessively low temperatures (<75℃) causing a slow film formation rate and incomplete coating. Through the synergistic effect of these steps, the matrix structure of the functional particles becomes more stable, and the surface functional layer becomes more uniform, ultimately achieving precise control over the bubble stability, interfacial adhesion, and overall mechanical properties of autoclaved aerated concrete (AAC) panels.

[0015] This solution also proposes a method for preparing the above-mentioned autoclaved aerated concrete slab, including the following steps: Dry mixing of binder: Add lime, cement, and desulfurized gypsum to a mixer and dry mix at a mixing speed of 120-140 rpm for 5.0-7.0 min; Preparation of cementitious slurry: Add 65-75 parts of softened water at a temperature of 24-26℃ to the dry mixture and stir at a stirring speed of 140-150 rpm for 18-22 minutes. Preparation of gas-generating agent suspension: dilute aluminum powder with softened water at a water-to-powder mass ratio of 27-29:1, add 0.15-0.25 parts of saponin retarder, and stir at 600-700 rpm for 1.5-2.5 min at 40-50℃. Additives: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at a stirring speed of 160-180 rpm for 2.5-3.5 min; Adding functional particles: Adjust the stirring speed to 40-60 rpm, add the functional particles and stir for 50-70 seconds, control the slurry flowability to 190-210 mm and the pH value to 11.9-12.6; Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at a stirring speed of 110-130 rpm for 1.5-2.5 min; Static curing: Pour the mixture into the mold and cure for 2.5-3.5 hours at a temperature of 35-37℃, relative humidity of 95-100%, and carbon dioxide concentration below 0.5%. Cutting: When the compressive strength of the billet reaches 0.24-0.36 MPa, cut it into the predetermined size; Autoclaving: The cut blanks are autoclaved.

[0016] Preferably, the autoclaving process specifically includes: Vacuuming: After the billet is placed in the autoclave, vacuum is applied to -0.085 to -0.095 MPa and maintained for 14-16 minutes; Heating and pressurizing: Increase the temperature to 183-187℃ at a rate of 1.2-1.8℃ / min, and cure at a constant temperature and pressure of 1.15-1.25MPa saturated steam pressure for 10.0-12.0h; Cooling and discharging: Cool to 50-60℃ at a rate of 0.3-0.5℃ / min, then release pressure and discharge from the vessel.

[0017] Preferably, the slurry temperature is controlled at 29-36℃ before the functional particles are added.

[0018] Preferably, the ambient temperature fluctuation range during the static curing phase does not exceed ±0.5℃.

[0019] Preferably, the cutting process uses steel wire cutting with a wire diameter of 0.7-1.3 mm and a tension of 280-420 N.

[0020] Preferably, the steam saturation in the autoclave is not less than 95%.

[0021] As a preferred option, the concrete slab after exiting the autoclave is allowed to equilibrate its moisture content for 46-50 hours in an environment with a humidity of 58-72%.

[0022] Compared to existing technologies, the technical advantages of this solution are: 1. In terms of composition, a basic cementitious system is constructed using lime, cement, and desulfurized gypsum. The retarding effect of desulfurized gypsum provides a stable window for the gas generation of aluminum powder. At the same time, functional particles with steelmaking furnace ash as the matrix and silicone polyether loaded on the surface are introduced. This not only realizes the resource utilization of industrial waste residue, but also improves the structural density by utilizing components such as CaO and SiO2 in steelmaking furnace ash to participate in hydration and pozzolanic reactions. The loading of silicone polyether optimizes the interfacial bonding between particles and the cementitious system, enhancing the overall mechanical properties. Combined with polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent, the dispersibility is controlled, the setting time is matched, and the bubble structure is optimized, respectively. The use of softened water avoids the interference of impurity ions on the hydration process.

[0023] 2. In terms of process, a staged stirring strategy is adopted. By controlling the rotation speed and time at different stages, the uniform dry mixing of the binder, sufficient slurry preparation, and reasonable dispersion of additives and functional particles are ensured. The temperature control before the addition of functional particles and the optimization of the order of adding the gas generating agent ensure the synergy of gas generation and condensation rhythm. Strict temperature, humidity and environmental control during the static curing stage promotes uniform hardening of the green body. The precise control of cutting timing and parameters avoids damage to the green body. The process design of vacuuming, gradient heating and pressurization, constant temperature and pressure and slow cooling during autoclaving not only promotes the full hydration reaction, but also reduces structural defects caused by thermal stress. The control of equilibrium moisture content after exiting the autoclave further stabilizes the material properties. The whole system forms a complete system from the synergy of raw material components to the precise control of process parameters, and achieves a comprehensive improvement in the material's lightweight and high strength, excellent durability and process stability. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. To enable those skilled in the art to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0025] An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 110-120 parts lime; 140-150 parts cement; 50-55 parts of desulfurized gypsum; 9-11 parts aluminum powder; 8-15 parts of functional particles; 0.15-0.25 parts of polycarboxylate superplasticizer, with a solid content of 25%; Citric acid retarder 0.08-0.12 parts, citric acid retarder purity greater than 99%; Rosin thermal polymer air-entraining agent 0.08-0.12 parts; 65-75 parts softened water, with a hardness of less than 50 mg / L; The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 1.5-2.5% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag. Its chemical composition, by mass, includes 30-60 parts CaO, 10-25 parts SiO2, 5-15 parts Al2O3, 3-12 parts MgO, and 10-20 parts Fe2O3.

[0026] Steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​350-400 m² 2 After being granulated, the particle size is 0.5-2.0 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 30-50%. Methods for preparing functional particles include: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​350-400 m². 2 / kg, to obtain steelmaking furnace ash powder; Granulation and molding: Add 8-12% of the mass of cement and 10-15% of the mass of water to the steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw material particles with a particle size of 0.5-2.0mm. Curing and solidification: The raw material particles are cured at a temperature of 24-26℃ and a relative humidity of 95-100% for 48-72 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Place the steelmaking furnace ash matrix particles in a rotary drum coating machine and spray a silicone polyether emulsion with a solid content of 40-50%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 1.5-2.5% of the matrix particle mass, and the inlet air temperature is 55-65℃. Curing treatment: After spraying, the particles are cured in hot air circulation at 78-82℃ for 1.5-2.0 hours to obtain functional particles.

[0027] A method for preparing autoclaved aerated concrete (AAC) panels includes the following steps: Dry mixing of binder: Add lime, cement, and desulfurized gypsum to a mixer and dry mix at a mixing speed of 120-140 rpm for 5.0-7.0 min; Preparation of cementitious slurry: Add 65-75 parts of softened water at a temperature of 24-26℃ to the dry mixture and stir at a stirring speed of 140-150 rpm for 18-22 minutes. Preparation of gas-generating agent suspension: dilute aluminum powder with softened water at a water-to-powder mass ratio of 27-29:1, add 0.15-0.25 parts of saponin retarder, and stir at 600-700 rpm for 1.5-2.5 min at 40-50℃. Additives: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at a stirring speed of 160-180 rpm for 2.5-3.5 min; Adding functional particles: Adjust the stirring speed to 40-60 rpm, add the functional particles and stir for 50-70 seconds, control the slurry flowability to 190-210 mm and the pH value to 11.9-12.6; control the slurry temperature to 29-36℃ before adding the functional particles. Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at a stirring speed of 110-130 rpm for 1.5-2.5 min; Static curing: Pour the mixture into the mold and cure for 2.5-3.5 hours in an environment with a temperature of 35-37℃, relative humidity of 95-100%, and carbon dioxide concentration below 0.5%; the ambient temperature fluctuation range during the static curing stage shall not exceed ±0.5℃. Cutting: When the compressive strength of the billet reaches 0.24-0.36MPa, cut it into the predetermined size; use steel wire cutting, with a wire diameter of 0.7-1.3mm and a tension of 280-420N; Autoclaving: The cut blanks are autoclaved. The specific steps of autoclaving are: Vacuuming: After the billet is placed in the autoclave, vacuum is applied to -0.085 to -0.095 MPa and maintained for 14-16 minutes; Heating and pressurizing: Increase the temperature to 183-187℃ at a rate of 1.2-1.8℃ / min, and maintain constant temperature and pressure for 10.0-12.0h at a saturated steam pressure of 1.15-1.25MPa; the steam saturation in the autoclave should not be less than 95%. Cooling and unloading: Cool the concrete slab to a reactor temperature of 50-60℃ at a rate of 0.3-0.5℃ / min, depressurize and unload the slab. Allow the unloaded concrete slab to equilibrate its moisture content in an environment with a humidity of 58-72% for 46-50 hours.

[0028] Example 1 An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 115 parts lime; 145 parts cement; 52.5 parts desulfurized gypsum; 10 parts aluminum powder; 11.5 parts functional particles; 0.20 parts polycarboxylate superplasticizer with a solid content of 25%; 0.10 parts citric acid retarder with a purity greater than 99%; 0.10 parts rosin thermal polymer air-entraining agent; 70 parts softened water with a hardness of less than 50 mg / L. The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 2.0% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag. Its chemical composition, by mass, includes 45 parts CaO, 17.5 parts SiO2, 10 parts Al2O3, 7.5 parts MgO, and 20 parts Fe2O3. The steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​375 m² / kg and then granulated. The particle size is 1.25 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 40%. Methods for preparing functional particles include: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​375 m² / kg to obtain steelmaking furnace ash powder; Granulation and molding: Add 10% by weight of cement and 12.5% ​​by weight of water to steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw meal particles with a particle size of 1.25mm. Curing and solidification: The raw material particles were cured at 25℃ and 97.5% relative humidity for 60 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Steelmaking furnace ash matrix particles are placed in a rotary drum coating machine and sprayed with a silicone polyether emulsion with a solid content of 45%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 2.0% of the matrix particles, and the inlet air temperature is 60℃. Curing treatment: After spraying, the particles are cured for 1.75 hours under hot air circulation at 80℃ to obtain functional particles.

[0029] A method for preparing autoclaved aerated concrete (AAC) panels includes the following steps: Dry mixing of binder: Add lime, cement and desulfurized gypsum to the mixer and dry mix at a mixing speed of 130 rpm for 6.0 min; Preparation of cementitious slurry: Add 70 parts of softened water at 25°C to the dry mixture and stir at 145 rpm for 20 min. Preparation of gas-generating agent suspension: Aluminum powder was diluted with softened water at a water-to-powder mass ratio of 28:1, and 0.20 parts of saponin retarder were added. The mixture was stirred at 45°C and 650 rpm for 2.0 min. Additive addition: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at 170 rpm for 3.0 min; Adding functional particles: Adjust the stirring speed to 50 rpm, add the functional particles and stir for 60 seconds, control the slurry flowability to 200 mm and the pH value to 12.25; control the slurry temperature to 32.5℃ before adding the functional particles. Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at 120 rpm for 2.0 min; Static curing: Pour the mixture into the mold and cure for 3.0 hours in an environment with a temperature of 36℃, a relative humidity of 97.5%, and a carbon dioxide concentration of less than 0.5%; the ambient temperature fluctuation range during the static curing stage shall not exceed ±0.5℃. Cutting: When the compressive strength of the billet reaches 0.30MPa, it is cut into the predetermined size; steel wire cutting is used, with a wire diameter of 1.0mm and a tension of 350N; Autoclaving: The cut blanks are autoclaved. The specific steps of autoclaving are: Vacuuming: After the billet is placed in the autoclave, vacuum is applied to -0.090 MPa and maintained for 15 min; Heating and pressurizing: Heat to 185℃ at a rate of 1.5℃ / min, and maintain constant temperature and pressure for 11.0h under saturated steam pressure of 1.20MPa; the steam saturation in the autoclave should not be less than 95%; Cooling and unloading: Cool to 55℃ at a rate of 0.4℃ / min, depressurize and unload the concrete slab. After unloading, allow the concrete slab to equilibrate to a moisture content of 65% for 48 hours.

[0030] Example 2 An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 110 parts lime; 140 parts cement; 50 parts desulfurized gypsum; 9 parts aluminum powder; 8 parts functional granules; 0.15 parts polycarboxylate superplasticizer with a solid content of 25%; 0.08 parts citric acid retarder with a purity greater than 99%; 0.08 parts rosin thermal polymer air-entraining agent; 65 parts softened water with a hardness of less than 50 mg / L. The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 1.5% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag. Its chemical composition, by mass, includes 30 parts CaO, 10 parts SiO2, 5 parts Al2O3, 3 parts MgO, and 10 parts Fe2O3. The steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​350 m² / kg and then granulated. The particle size is 0.5 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 30%. Methods for preparing functional particles include: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​350 m² / kg to obtain steelmaking furnace ash powder; Granulation and molding: Add 8% by weight of cement and 10% by weight of water to steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw meal particles with a particle size of 0.5 mm. Curing and solidification: Raw material particles are cured at 24℃ and 95% relative humidity for 48 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Steelmaking furnace ash matrix particles are placed in a rotary drum coating machine and sprayed with a silicone polyether emulsion with a solid content of 40%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 1.5% of the matrix particles, and the inlet air temperature is 55℃. Curing treatment: After spraying, the particles are cured for 1.5 hours under hot air circulation at 78℃ to obtain functional particles.

[0031] A method for preparing autoclaved aerated concrete (AAC) panels includes the following steps: Dry mixing of binder: Add lime, cement and desulfurized gypsum to the mixer and dry mix at a mixing speed of 120 rpm for 5.0 min; Preparation of cementitious slurry: Add 65 parts of softened water at 24℃ to the dry mixture and stir at 140 rpm for 18 min. Preparation of gas-generating agent suspension: Aluminum powder was diluted with softened water at a water-to-powder mass ratio of 27:1, and 0.15 parts of saponin retarder were added. The mixture was stirred at 600 rpm for 1.5 min at 40℃. Additive addition: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at 160 rpm for 2.5 min; Adding functional particles: Adjust the stirring speed to 40 rpm, add the functional particles and stir for 50 seconds, control the slurry flowability to 190 mm and the pH value to 11.9; control the slurry temperature to 29℃ before adding the functional particles. Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at 110 rpm for 1.5 min; Static curing: Pour the mixture into the mold and cure for 2.5 hours in an environment with a temperature of 35℃, relative humidity of 95%, and carbon dioxide concentration below 0.5%; the ambient temperature fluctuation range during the static curing stage shall not exceed ±0.5℃. Cutting: When the compressive strength of the billet reaches 0.24MPa, it is cut into the predetermined size; steel wire cutting is used, with a wire diameter of 0.7mm and a tension of 280N; Autoclaving: The cut blanks are autoclaved. The specific steps of autoclaving are: Vacuuming: After the billet is placed in the autoclave, a vacuum is drawn to -0.085 MPa and maintained for 14 min; Heating and pressurizing: Increase the temperature to 183℃ at a rate of 1.2℃ per minute, and maintain constant temperature and pressure for 10.0h under saturated steam pressure of 1.15MPa; the steam saturation in the autoclave should not be less than 95%; Cooling and unloading: Cool the concrete slab to 50°C at a rate of 0.3°C per minute, depressurize and unload the slab. Allow the slab to equilibrate its moisture content in an environment with 58% humidity for 46 hours.

[0032] Example 3 An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 120 parts lime; 150 parts cement; 55 parts desulfurized gypsum; 11 parts aluminum powder; 15 parts functional granules; 0.25 parts polycarboxylate superplasticizer with a solid content of 25%; 0.12 parts citric acid retarder with a purity greater than 99%; 0.12 parts rosin thermal polymer air-entraining agent; 75 parts softened water with a hardness of less than 50 mg / L. The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 2.5% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag. Its chemical composition, by mass, includes 60 parts CaO, 25 parts SiO2, 15 parts Al2O3, 12 parts MgO, and 30 parts Fe2O3. The steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​400 m² / kg and then granulated. The particle size is 2.0 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 50%. Methods for preparing functional particles include: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​400 m² / kg to obtain steelmaking furnace ash powder; Granulation and molding: Add 12% by weight of cement and 15% by weight of water to steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw meal particles with a particle size of 2.0 mm. Curing and solidification: Raw material particles are cured at 26℃ and 100% relative humidity for 72 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Steelmaking furnace ash matrix particles are placed in a rotary drum coating machine and sprayed with a silicone polyether emulsion with a solid content of 50%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 2.5% of the matrix particles, and the inlet air temperature is 65℃. Curing treatment: After spraying, the particles are cured under hot air circulation at 82℃ for 2.0h to obtain functional particles.

[0033] A method for preparing autoclaved aerated concrete (AAC) panels includes the following steps: Dry mixing of binder: Add lime, cement and desulfurized gypsum to the mixer and dry mix at a mixing speed of 140 rpm for 7.0 min; Preparation of cementitious slurry: Add 75 parts of softened water at 26℃ to the dry mixture and stir at 150 rpm for 22 min. Preparation of gas-generating agent suspension: Aluminum powder was diluted with softened water at a water-to-powder mass ratio of 29:1, and 0.25 parts of saponin retarder were added. The mixture was stirred at 700 rpm for 2.5 min at 50℃. Additive addition: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at 180 rpm for 3.5 min; Adding functional particles: Adjust the stirring speed to 60 rpm, add the functional particles and stir for 70 seconds, control the slurry flowability to 210 mm and the pH value to 12.6; control the slurry temperature to 36℃ before adding the functional particles. Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at 130 rpm for 2.5 min; Static curing: Pour the mixture into the mold and cure for 3.5 hours in an environment with a temperature of 37℃, relative humidity of 100%, and carbon dioxide concentration of less than 0.5%; the ambient temperature fluctuation range during the static curing stage shall not exceed ±0.5℃. Cutting: When the compressive strength of the billet reaches 0.36MPa, it is cut into the predetermined size; steel wire cutting is used, with a wire diameter of 1.3mm and a tension of 420N; Autoclaving: The cut blanks are autoclaved. The specific steps of autoclaving are: Vacuuming: After the billet is placed in the autoclave, vacuum is applied to -0.095 MPa and maintained for 16 min; Heating and pressurizing: The temperature is increased to 187℃ at a rate of 1.8℃ per minute, and then cured at a constant temperature and pressure of 1.25MPa saturated steam pressure for 12.0h; the steam saturation in the autoclave is not less than 95%; Cooling and unloading: Cool the concrete slab to 60°C at a rate of 0.5°C per minute, depressurize and unload it from the autoclave. Allow the unloaded concrete slab to equilibrate its moisture content for 50 hours in an environment with 72% humidity.

[0034] Example 4 An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 112 parts lime; 142 parts cement; 51 parts desulfurized gypsum; 9.5 parts aluminum powder; 9 parts functional particles; 0.18 parts polycarboxylate superplasticizer with a solid content of 25%; 0.09 parts citric acid retarder with a purity greater than 99%; 0.09 parts rosin thermal polymer air-entraining agent; 67 parts softened water with a hardness of less than 50 mg / L. The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 1.8% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag. Its chemical composition, by mass, includes 35 parts CaO, 12 parts SiO2, 7 parts Al2O3, 5 parts MgO, and 15 parts Fe2O3. The steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​360 m² / kg and then granulated. The particle size is 0.8 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 35%. Methods for preparing functional particles include: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​360 m² / kg to obtain steelmaking furnace ash powder; Granulation and molding: Add 9% by weight of cement and 11% by weight of water to steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw meal particles with a particle size of 0.8 mm. Curing and solidification: Raw material particles are cured at 24.5℃ and 96% relative humidity for 52 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Steelmaking furnace ash matrix particles are placed in a rotary drum coating machine and sprayed with a silicone polyether emulsion with a solid content of 42%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 1.8% of the matrix particles, and the inlet air temperature is 57℃. Curing treatment: After spraying, the particles are cured for 1.6 hours under hot air circulation at 79℃ to obtain functional particles.

[0035] A method for preparing autoclaved aerated concrete (AAC) panels includes the following steps: Dry mixing of binder: Add lime, cement and desulfurized gypsum to the mixer and dry mix at a mixing speed of 125 rpm for 5.5 minutes; Preparation of cementitious slurry: Add 67 parts of softened water at 24.5℃ to the dry mixture and stir at 142 rpm for 19 min. Preparation of gas-generating agent suspension: Aluminum powder was diluted with softened water at a water-to-powder mass ratio of 27.5:1, and 0.18 parts of saponin retarder were added. The mixture was stirred at 42℃ and 620 rpm for 1.8 min. Additive addition: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at 165 rpm for 2.8 min; Adding functional particles: Adjust the stirring speed to 45 rpm, add the functional particles and stir for 55 seconds, control the slurry flowability to 195 mm and the pH value to 12.0; control the slurry temperature to 30℃ before adding the functional particles. Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at 115 rpm for 1.8 min; Static curing: Pour the mixture into the mold and cure for 2.8 hours in an environment with a temperature of 35.5℃, a relative humidity of 96%, and a carbon dioxide concentration of less than 0.5%; the ambient temperature fluctuation range during the static curing stage shall not exceed ±0.5℃. Cutting: When the compressive strength of the billet reaches 0.25MPa, it is cut into the predetermined size; steel wire cutting is used, with a wire diameter of 0.8mm and a tension of 320N; Autoclaving: The cut blanks are autoclaved. The specific steps of autoclaving are: Vacuuming: After the billet is placed in the autoclave, a vacuum is drawn to -0.087 MPa and maintained for 14.5 min; Heating and pressurizing: The temperature is increased to 184℃ at a rate of 1.3℃ per minute, and then cured at a constant temperature and pressure of 1.18MPa saturated steam pressure for 10.5 hours; the steam saturation in the autoclave is not less than 95%; Cooling and unloading: Cool the concrete slab to 52°C at a rate of 0.35°C per minute, depressurize and unload the slab. Allow the unloaded concrete slab to equilibrate its moisture content for 47 hours in an environment with 62% humidity.

[0036] Example 5 An autoclaved aerated concrete (AAC) panel comprises the following raw materials in parts by weight: 118 parts lime; 148 parts cement; 54 parts desulfurized gypsum; 10.5 parts aluminum powder; 14 parts functional particles; 0.22 parts polycarboxylate superplasticizer with a solid content of 25%; 0.11 parts citric acid retarder with a purity greater than 99%; 0.11 parts rosin thermal polymer air-entraining agent; 73 parts softened water with a hardness of less than 50 mg / L. The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 2.3% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag. Its chemical composition, by mass, includes 55 parts CaO, 22 parts SiO2, 13 parts Al2O3, 10 parts MgO, and 25 parts Fe2O3. The steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​390 m² / kg and then granulated. The particle size is 1.8 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 45%. Methods for preparing functional particles include: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​390 m² / kg to obtain steelmaking furnace ash powder; Granulation and molding: 11% of the mass of cement and 14% of the mass of water are added to steelmaking furnace ash powder, mixed evenly, and then extruded and granulated to obtain raw meal particles with a particle size of 1.8mm. Curing and solidification: Raw material particles are cured at 25.5℃ and 99% relative humidity for 68 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Steelmaking furnace ash matrix particles are placed in a rotary drum coating machine and sprayed with a silicone polyether emulsion with a solid content of 48%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 2.3% of the matrix particles, and the inlet air temperature is 63℃. Curing treatment: After spraying, the particles are cured for 1.9 hours under hot air circulation at 81℃ to obtain functional particles.

[0037] A method for preparing autoclaved aerated concrete (AAC) panels includes the following steps: Dry mixing of binder: Add lime, cement and desulfurized gypsum to the mixer and dry mix at a mixing speed of 138 rpm for 6.8 minutes; Preparation of cementitious slurry: Add 73 parts of softened water at 25.5℃ to the dry mixture and stir at 148 rpm for 21 min. Preparation of gas-generating agent suspension: Aluminum powder was diluted with softened water at a water-to-powder mass ratio of 28.5:1, and 0.22 parts of saponin retarder were added. The mixture was stirred at 48℃ and 680 rpm for 2.3 min. Additive addition: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at 175 rpm for 3.3 min; Adding functional particles: Adjust the stirring speed to 55 rpm, add the functional particles and stir for 65 seconds, control the slurry flowability to 205 mm and the pH value to 12.5; control the slurry temperature to 35℃ before adding the functional particles. Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at 125 rpm for 2.3 min; Static curing: Pour the mixture into the mold and cure for 3.3 hours in an environment with a temperature of 36.5℃, relative humidity of 99%, and carbon dioxide concentration below 0.5%; the ambient temperature fluctuation range during the static curing stage shall not exceed ±0.5℃. Cutting: When the compressive strength of the billet reaches 0.34MPa, it is cut into the predetermined size; steel wire cutting is used, with a wire diameter of 1.2mm and a tension of 400N; Autoclaving: The cut blanks are autoclaved. The specific steps of autoclaving are: Vacuuming: After the billet is placed in the autoclave, a vacuum is drawn to -0.093 MPa and maintained for 15.5 min; Heating and pressurizing: The temperature is increased to 186℃ at a rate of 1.7℃ per minute, and then cured at a constant temperature and pressure of 1.22MPa saturated steam pressure for 11.5 hours; the steam saturation in the autoclave is not less than 95%; Cooling and unloading: Cool the concrete slab to 58°C at a rate of 0.45°C per minute, depressurize and unload the slab. Allow the unloaded concrete slab to equilibrate to a moisture content of 49 hours in an environment with 70% humidity.

[0038] Comparative Example 1 The only difference from Example 1 is that there are no functional particles.

[0039] Comparative Example 2 The only difference from Example 1 is that the amount of functional particles added is 20 parts.

[0040] Comparative Example 3 The only difference from Example 1 is that silicone polyether was not sprayed on the surface during the preparation of the functional particles.

[0041] Comparative Example 4 The only difference from Example 1 is that the amount of silicone polyether sprayed on the surface during the preparation of functional particles is 3%.

[0042] Comparative Example 5 The only difference from Example 1 is that the slurry temperature is controlled at 38°C before the functional particles are added.

[0043] Comparative Example 6 The only difference from Example 1 is that the steelmaking furnace ash matrix is ​​made by grinding and granulating converter slag or electric furnace slag, and its chemical composition, by mass, includes 65 parts CaO, 15 parts SiO2, 8 parts Al2O3, 5 parts MgO, and 37 parts Fe2O3. Comparative Example 7 The only difference from Example 1 is that softened water was not used, and the water hardness was 60 mg / L.

[0044] Comparative Example 8 The only difference from Example 1 is that the gas-generating agent is added first, followed by the functional particles: Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at 120 rpm for 2.0 min; Adding functional particles: Adjust the stirring speed to 50 rpm, add the functional particles and stir for 60 seconds, control the slurry flowability to 200 mm and the pH value to 12.25; control the slurry temperature to 32.5℃ before adding the functional particles.

[0045] Comparative Example 9 The only difference from Example 1 is that the stirring speed is controlled at 150 rpm throughout the entire preparation process of the autoclaved aerated concrete slab.

[0046] Comparative Example 10 The only difference from Example 1 is that the ambient temperature fluctuation range during the static curing phase is ±2℃.

[0047] Comparative Example 11 The only difference from Example 1 is the heating and pressurization: the temperature is increased to 190°C at a rate of 12°C / min, and then cured at a constant temperature and pressure of 1.3MPa saturated steam pressure for 11.0h.

[0048] Comparative Example Twelve The only difference from Example 1 is the heating and pressurization: the temperature is increased to 180°C at a rate of 1°C / min, and then cured at a constant temperature and pressure of 1.0MPa saturated steam pressure for 11.0h.

[0049] Comparative Example Thirteen The only difference from Example 1 is that the temperature was reduced to 55°C at a rate of 0.8°C / min, the pressure was released and the concrete slab was removed from the reactor. The concrete slab was then allowed to equilibrate its moisture content for 48 hours in an environment with 75% humidity.

[0050] Comparative Example 14 The only difference from Example 1 is that the temperature was reduced to 65°C at a rate of 0.4°C / min, the pressure was released and the concrete slab was removed from the reactor. The concrete slab was then allowed to equilibrate its moisture content for 48 hours in an environment with 65% humidity.

[0051] Test method reference: GB / T11969-2020 "Test Methods for Performance of Autoclaved Aerated Concrete".

[0052] The test results are shown in Table 1.

[0053] Table 1. Test results of the examples and comparative examples. The performance characteristics of the embodiments stem from the synergistic control of raw material ratios, functional particle design, and process parameters. From the perspective of raw materials, the cementitious system composed of lime, cement, and desulfurized gypsum provides the basis for the hydration reaction. The amounts of lime and cement determine the production of hydrated calcium silicate, CaO, and ettringite, while desulfurized gypsum provides a stable window for aluminum powder gas generation through its retarding effect. Functional particles, as the core reinforcing phase, are synergistically enhanced by their dosage, surface silicone polyether loading, and the composition of the steelmaking furnace ash matrix. This not only promotes CSH formation by supplementing calcium ions with CaO and filling pores through the pozzolanic reaction of SiO2 and CH, but also reduces the surface tension between the particles and the cementitious system through the interfacial modification effect of silicone polyether, enhancing interfacial adhesion and reducing defects in the transition zone. Furthermore, the catalytic effect of Fe2O3 and the later-stage strength contribution of MgO further optimize structural integrity. The preparation process of functional particles ensures the stability of the matrix activity and the surface functional layer, enabling them to be uniformly dispersed in the slurry. These particles act as a rigid framework to bear the load, and through the foam-stabilizing effect of silicone polyether and the synergistic effect of rosin thermal polymer air-entraining agent, they regulate bubble size and distribution, achieving a balance between lightweight and high strength. At the process level, stirring parameters and temperature control ensure the uniformity of component dispersion and the matching of gas generation-condensation rhythms. The gradient parameters of autoclaving promote further formation and interweaving of CSH gel through sufficient hydration reaction and structural densification, reducing porosity. Therefore, with the increase of functional particle dosage, the increase of active ingredient content, and the optimization of process parameters, such as extended autoclaving time and increased silicone polyether loading, the performance of the examples shows a trend of decreased dry density, increased compressive strength, and decreased water absorption and drying shrinkage. Furthermore, the optimization of freeze resistance and carbonization coefficient confirms the decisive role of structural uniformity and interface integrity in durability, ultimately demonstrating a multi-scale synergistic enhancement mechanism.

[0054] Comparative Example 1, lacking functional particles, lacks their interfacial reinforcement and bubble stabilization effects, leading to a weak transition zone between the gelation system and the bubble structure. This results in increased dry density and decreased compressive strength, increased water absorption and shrinkage, and deteriorated freeze-thaw resistance and carbonation performance. Comparative Example 2 contains excessive functional particles, exceeding the reasonable dispersion threshold. This leads to particle agglomeration, forming stress concentration points and disrupting structural uniformity. Although rigidity is improved, overall strength and durability are inferior to Example 1. Comparative Example 3's functional particles are not loaded with silicone polyether, resulting in high surface energy and poor compatibility with the gelation system. This leads to weak interfacial adhesion, easy bubble coalescence and growth, increased porosity, and all performance characteristics inferior to Example 1. Example 4: The excessive loading of silicone polyether weakened the mechanical interlocking force between the particles and the matrix due to excessive lubrication, resulting in a decrease in interfacial bonding strength. Although the foam stabilization effect was slightly better, the overall performance was still inferior to Example 1. Comparative Example 5: The slurry temperature was too high before the addition of functional particles, accelerating the aluminum powder reaction rate, causing an imbalance between gas generation and condensation rhythms, uneven bubble distribution, and a tendency to form large bubbles, increasing structural defects and significantly reducing strength and freeze resistance. Comparative Example 6: Excessive CaO in steelmaking furnace ash caused excessive alkalinity in the slurry, damaging the aluminum powder passivation film, resulting in violent and uncontrolled gas generation. The billet was prone to mold collapse or honeycomb structure, leading to a sharp drop in strength and a significant increase in water absorption and shrinkage. Comparative Example 7: No softened water was used, and calcium and magnesium... Ions react with cementitious materials to form precipitates, interfering with the hydration process, reducing structural density, and weakening strength and durability. In Comparative Example 8, the addition of a gas-generating agent before the addition of functional particles disrupts the already formed bubble film, leading to severe bubble aggregation, coarsening of the pore structure, and performance inferior to Example 1. In Comparative Example 9, with a constant stirring speed, the functional particles and cementitious materials are unevenly dispersed, resulting in local aggregation or insufficient dispersion, poor structural uniformity, and decreased strength and frost resistance. In Comparative Example 10, excessive fluctuations in the static temperature cause the gas generation rate to fluctuate wildly with temperature changes, resulting in disordered bubble size and distribution, compromised structural integrity, and overall performance degradation. In Comparative Example 11, autoclaving and heating... Excessive speed and high temperature and pressure caused thermal stress concentration inside the green body, resulting in microcracks, damage to structural integrity, and significant deterioration in strength and freeze resistance. Comparative Example 12 had slow autoclaving and insufficient temperature and pressure, resulting in incomplete hydration reaction, low CSH gel formation, poor structural density, and lower strength and durability than Example 1. Comparative Example 13 experienced excessively rapid cooling and high ambient humidity, causing shrinkage stress due to temperature differences inside the green body, leading to cracking. Excessive moisture absorption after exiting the autoclave increased porosity and reduced performance. Comparative Example 14 had an excessively high final cooling temperature, resulting in a large temperature gradient when the green body exited the autoclave, which easily caused microdefects. Although the impact was less than that of the other comparative examples, the performance was still inferior to Example 1.

[0055] 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 any equivalent structural transformations made under the concept of the present invention and using the content of the present invention specification should be covered within the scope of protection of the claims of the present invention.

Claims

1. An autoclaved aerated concrete (AAC) slab, characterized in that, The raw materials include the following parts by weight: 110-120 parts lime; 140-150 parts cement; 50-55 parts of desulfurized gypsum; 9-11 parts aluminum powder; 8-15 parts of functional particles; 0.15-0.25 parts of polycarboxylate superplasticizer; Citric acid retarder 0.08-0.12 parts; Rosin thermal polymer air-entraining agent 0.08-0.12 parts; 65-75 parts of softened water, wherein the hardness of the softened water is less than 50 mg / L; The functional particles are composite particles with steelmaking furnace ash matrix as the core and silicone polyether surfactant loaded on the surface. The silicone polyether surfactant loading is 1.5-2.5% of the total mass of the functional particles, and the moisture content of the functional particles is less than or equal to 5%. The steelmaking furnace ash matrix is ​​formed by grinding and granulating converter slag or electric furnace slag, and its chemical composition, by mass, includes 30-60 parts CaO, 10-25 parts SiO2, 5-15 parts Al2O3, 3-12 parts MgO, and 10-20 parts Fe2O3.

2. The autoclaved aerated concrete slab as described in claim 1, characterized in that: The steelmaking furnace ash matrix is ​​ground to a specific surface area of ​​350-400 m². 2 After being granulated, the particle size is 0.5-2.0 mm, the compressive strength is not less than 5.0 MPa, and the water absorption rate is 30-50%.

3. The autoclaved aerated concrete slab as described in claim 1 or 2, characterized in that: The method for preparing the functional particles includes: Steelmaking furnace ash pretreatment: Grind converter slag or electric furnace slag to a specific surface area of ​​350-400 m². 2 / kg, to obtain steelmaking furnace ash powder; Granulation and molding: Add 8-12% of the mass of cement and 10-15% of the mass of water to the steelmaking furnace ash powder, mix evenly, and then extrude and granulate to obtain raw material particles with a particle size of 0.5-2.0mm. Curing and solidification: The raw material particles are cured at a temperature of 24-26℃ and a relative humidity of 95-100% for 48-72 hours to obtain steelmaking furnace ash matrix particles; Surfactant loading: Place the steelmaking furnace ash matrix particles in a rotary drum coating machine and spray a silicone polyether emulsion with a solid content of 40-50%. The spraying amount is controlled according to the dry matter of silicone polyether accounting for 1.5-2.5% of the matrix particle mass, and the inlet air temperature is 55-65℃. Curing treatment: After spraying, the particles are cured in hot air circulation at 78-82℃ for 1.5-2.0 hours to obtain functional particles.

4. A method for preparing autoclaved aerated concrete (AAC) panels according to any one of claims 1-3, characterized in that, Includes the following steps: Dry mixing of binder: Add lime, cement, and desulfurized gypsum to a mixer and dry mix at a mixing speed of 120-140 rpm for 5.0-7.0 min; Preparation of cementitious slurry: Add 65-75 parts of softened water at a temperature of 24-26℃ to the dry mixture and stir at a stirring speed of 140-150 rpm for 18-22 minutes. Preparation of gas-generating agent suspension: dilute aluminum powder with softened water at a water-to-powder mass ratio of 27-29:1, add 0.15-0.25 parts of saponin retarder, and stir at 600-700 rpm for 1.5-2.5 min at 40-50℃. Additives: Add polycarboxylate superplasticizer, citric acid retarder, and rosin thermal polymer air-entraining agent to the cementitious slurry, and stir at a stirring speed of 160-180 rpm for 2.5-3.5 min; Adding functional particles: Adjust the stirring speed to 40-60 rpm, add the functional particles and stir for 50-70 seconds, control the slurry flowability to 190-210 mm and the pH value to 11.9-12.6; Adding the gas-generating agent: Add the gas-generating agent suspension to the slurry and stir at a stirring speed of 110-130 rpm for 1.5-2.5 min; Static curing: Pour the mixture into the mold and cure for 2.5-3.5 hours at a temperature of 35-37℃, relative humidity of 95-100%, and carbon dioxide concentration below 0.5%. Cutting: When the compressive strength of the billet reaches 0.24-0.36 MPa, cut it into the predetermined size; Autoclaving: The cut blanks are autoclaved.

5. The method for preparing autoclaved aerated concrete (AAC) panels as described in claim 4, characterized in that: The autoclaving process specifically includes: Vacuuming: After the billet is placed in the autoclave, vacuum is applied to -0.085 to -0.095 MPa and maintained for 14-16 minutes; Heating and pressurizing: Increase the temperature to 183-187℃ at a rate of 1.2-1.8℃ / min, and cure at a constant temperature and pressure of 1.15-1.25MPa saturated steam pressure for 10.0-12.0h; Cooling and discharging: Cool to 50-60℃ at a rate of 0.3-0.5℃ / min, then release pressure and discharge from the vessel.

6. The method for preparing autoclaved aerated concrete (AAC) panels as described in claim 4, characterized in that: The slurry temperature before the functional particles are added is controlled at 29-36℃.

7. The method for preparing autoclaved aerated concrete (AAC) panels as described in claim 4, characterized in that: The ambient temperature fluctuation range during the static shutdown and maintenance phase shall not exceed ±0.5℃.

8. The method for preparing autoclaved aerated concrete (AAC) panels as described in claim 4, characterized in that: The cutting process uses steel wire cutting with a wire diameter of 0.7-1.3mm and a tension of 280-420N.

9. The method for preparing autoclaved aerated concrete (AAC) panels as described in claim 4, characterized in that: The steam saturation level inside the autoclave is not less than 95%.

10. The method for preparing autoclaved aerated concrete (AAC) panels as described in claim 4, characterized in that: After exiting the autoclave, the concrete slabs are allowed to equilibrate to a moisture content of 46-50 hours in an environment with a humidity of 58-72%.

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