An aerated concrete floor support plate, a preparation method and application thereof

Abstract

The application relates to the technical field of floor concrete, and particularly discloses an aerated concrete floor support plate and a preparation method and application thereof. The aerated concrete floor support plate is prepared from the following raw materials: cement, fly ash, mortar, modified expanded perlite, composite modified diatomite, metakaolin, composite fiber, a gas-releasing agent, a foam stabilizer, a water-reducing agent and water; the modified expanded perlite is obtained by modifying expanded perlite with a composite modifier, wherein the composite modifier comprises silane coupling agent KH-550, EVA resin powder and an ethanol aqueous solution; and the composite modified diatomite is obtained by modifying diatomite with aluminum chloride and silane coupling agent KH-570 in steps. The aerated concrete floor support plate has better impermeability and fire resistance while ensuring structural strength, thereby providing effective technical support for the popularization and application of the aerated concrete floor support plate.

Description

Technical Field

[0001] This application relates to the field of concrete floor slab technology, and more specifically, to an aerated concrete floor deck, its preparation method, and its application. Background Technology

[0002] Concrete floor slabs are a crucial component of building structures, bearing the important functions of transferring vertical loads and dividing building spaces. Their performance directly affects the safety, comfort, and durability of a building. Traditional concrete floor slabs are mostly made of ordinary Portland cement as the binder, combined with sand and gravel aggregates. While they possess a certain load-bearing capacity, they generally suffer from significant self-weight and poor thermal insulation performance. As modern architecture develops towards green, energy-saving, and lightweight designs, the limitations of traditional concrete floor slabs in meeting building energy efficiency standards and reducing overall structural loads are becoming increasingly apparent, necessitating the development of superior alternative materials and technologies.

[0003] Autoclaved aerated concrete (AAC) is a lightweight, porous building material formed by introducing numerous tiny closed pores into a concrete matrix. Its main raw materials include cement, lime, and siliceous materials, and it is manufactured through processes such as aeration, pouring, and curing. Due to its unique porous structure, AAC has been widely used in the construction industry, especially as wall panels, where it offers significant advantages: Firstly, the closed pores effectively block heat transfer, giving it thermal insulation properties far exceeding those of ordinary concrete, thus significantly reducing building heating and cooling energy consumption. Secondly, its porous structure provides excellent sound absorption and blocking, resulting in superior sound insulation and significantly improving the acoustic environment quality of building interiors, making it an ideal choice for wall materials in green buildings.

[0004] Given the outstanding performance of aerated concrete (APC) in wall panel applications, the industry is gradually exploring its application in floor slab fabrication, hoping to leverage its lightweight properties to reduce structural weight while maintaining thermal insulation and soundproofing performance. However, unlike walls, which primarily serve an enclosure function, floor slabs, as horizontal load-bearing components, place higher demands on the comprehensive performance of materials. APC applications in floor slabs have revealed several problems that urgently need to be addressed. Among these, poor impermeability is particularly prominent. Its porous structure easily allows moisture to penetrate, affecting not only the indoor environment but also potentially accelerating material degradation under environmental conditions such as freeze-thaw cycles. The potential fire resistance issues are equally significant. Although APC itself is a non-combustible material and meets basic fire protection requirements, floor slabs, as critical load-bearing components, experience a rapid decline in strength at high temperatures. Data shows that when temperatures reach above 600℃, the strength loss typically exceeds 50%. Without targeted fire-resistant reinforcement treatment, the rapid strength reduction during a fire can easily lead to structural collapse, thus limiting its large-scale promotion. Summary of the Invention

[0005] To enhance the impermeability and fire resistance of aerated concrete floor decking, this application provides an aerated concrete floor decking, its preparation method, and its application.

[0006] The aerated concrete floor deck provided in this application adopts the following technical solution: An aerated concrete floor deck, characterized in that it includes an aerated concrete slab and a steel mesh cage embedded in the aerated concrete slab for load-bearing. The aerated concrete panel comprises raw materials with the following components: The ingredients are: 30-50 parts cement, 20-30 parts fly ash, 5-12 parts mortar, 10-18 parts modified expanded perlite, 5-10 parts composite modified diatomaceous earth, 5-15 parts metakaolin, 3-8 parts composite fiber, 3-8 parts gypsum paste, 0.3-1.2 parts foaming agent, 0.1-0.5 parts foam stabilizer, 0.5-2.0 parts water-reducing agent, and 30-50 parts water. The modified expanded perlite is obtained by modifying expanded perlite with a composite modifier, which includes silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution. The composite modified diatomaceous earth is obtained by stepwise modification of diatomaceous earth with aluminum chloride and silane coupling agent KH-570.

[0007] By adopting the above technical solution, addressing the core issue of poor impermeability of aerated concrete floor decks, this solution introduces a synergistic effect of two modified components: "modified expanded perlite + composite modified diatomaceous earth," constructing a gradient-densified impermeability system. The mortar, acting as a highly active microfiller, fills the hydration pores of cement. The modified expanded perlite, after being modified with silane coupling agent KH-550 and EVA resin powder, exhibits significantly improved interfacial bonding between its surface and the cementitious material. The elastic film formed by the EVA resin seals interfacial micro-cracks, and combined with the densifying and reinforcing effect of nano-silica, it blocks the seepage channels easily formed by traditional perlite. The composite modified diatomaceous earth, after being modified with aluminum chloride channels, adsorbs free water and promotes hydration. The hydrophobicity imparted by the silane coupling agent KH-570, synergistically with the perlite, forms a gradient hydrophobic barrier. This dual protection effectively reduces the interconnected porosity of the matrix, thereby significantly enhancing the impermeability of the floor deck.

[0008] Regarding the improvement of fire resistance, the above-mentioned technical solution forms a dual protection of "high-temperature barrier + structural support" through component optimization. Metakaolin undergoes a phase transformation at high temperatures to generate structurally stable mullite crystals, which can form a dense protective layer on the material surface to hinder heat transfer; the basalt fiber in the composite fiber has a fire resistance temperature of over 800℃, which can maintain structural support capacity in a fire, while the polyacrylonitrile-based carbon fiber slowly carbonizes to form a carbon skeleton, which works in conjunction with hydration products to maintain structural integrity, effectively solving the hidden danger of floor slabs collapsing easily at high temperatures.

[0009] The above-mentioned solution enhances the impermeability and fire resistance while precisely preserving the original core advantages of aerated concrete floor decks. Modified expanded perlite and composite modified diatomaceous earth retain their lightweight and porous characteristics, and the uniform closed pores formed by the foaming agent result in thermal insulation performance superior to traditional concrete. The three-dimensional network structure of the composite fibers works synergistically with the porous system to improve sound wave absorption efficiency, effectively ensuring the sound insulation performance of the floor deck. Simultaneously, the reinforcing effects of the mortar, metakaolin, and composite fibers compensate for the strength limitations of lightweight materials, ensuring that the floor deck strength fully meets the requirements for non-load-bearing and auxiliary load-bearing floor decks.

[0010] From a technical, economic, and environmental perspective, the extensive use of fly ash in this solution enables the resource utilization of industrial waste, which aligns with the concept of green building development. The synergistic design of the two modified components avoids the increased cost caused by excessive use of a single modifier, and the preparation process is compatible with existing aerated concrete production equipment, enabling large-scale production without large-scale modifications, thus providing a feasible path for the promotion and application of aerated concrete floor decking.

[0011] Optionally, the composite fiber is composed of basalt fiber and polyacrylonitrile-based carbon fiber in a mass ratio of (2-5):1, and the length of the basalt fiber is 1-3 mm and the length of the polyacrylonitrile-based carbon fiber is 1-3 mm.

[0012] By adopting the above technical solution, the mass ratio of basalt fiber to polyacrylonitrile-based carbon fiber (2-5:1) can meet the dual requirements of high-temperature support and carbonized skeleton formation. The basalt fiber has a larger aspect ratio, which can effectively cross the micro-cracks in the matrix and inhibit crack propagation through bridging, reducing water penetration channels. The two fibers work together to improve the toughness and flexural strength of aerated concrete panels. At the same time, due to the short fiber length, it will not affect the subsequent cutting process of aerated concrete floor decking, and no additional adjustment to cutting equipment and process is required.

[0013] Optionally, the modified expanded perlite is prepared using the following method: (1) Mix silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution, and stir for 10-30 min to obtain composite modifier; (2) Place the expanded perlite in an oven at 80-100℃ and dry for 2-4 hours. Then, immerse the dried expanded perlite in a composite modifier and sonicate it at 50-60℃ for 30-60 minutes. After filtration, dry it at 110-130℃ to obtain active expanded perlite. Then, mix the active expanded perlite with a nano silica dispersion and stir for 1-2 hours. After filtration, take the solid phase and dry it to obtain modified expanded perlite.

[0014] By adopting the above technical solution, the process effectively improves the interfacial bonding strength between perlite and cementitious materials, effectively sealing the interfacial water seepage channels; at the same time, the modified layer can successively play the roles of EVA softening and sealing and nano-silica melting and strengthening at high temperatures, improving thermal stability and preventing perlite from pulverizing at high temperatures.

[0015] Optionally, in step (1), the mass ratio of silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution is (3-6):(2-4):(90-95); the mass concentration of ethanol aqueous solution is 92%-96%.

[0016] Optionally, in step (2), the mass ratio of the dried expanded perlite to the composite modifier is 1:(4-6); the mass concentration of the nano silica dispersion is 12%-16%, and the mass ratio of the active expanded perlite to the nano silica dispersion is 1:(3-5).

[0017] Optionally, the composite modified diatomaceous earth is prepared using the following method: A. Mix diatomaceous earth with aluminum chloride solution, stir and react at 70-80℃ for 2-3 hours, filter, wash until neutral, and dry to obtain pore-modified diatomaceous earth; B. Immerse the pore-modified diatomaceous earth in a solution of silane coupling agent KH-570, reflux for 1-2 hours, cool and filter, and dry to obtain composite modified diatomaceous earth.

[0018] By adopting the above technical solution, a precise combination of pore control and hydrophobic modification is achieved through stepwise modification, enhancing the synergistic effect of impermeability. Step A, the aluminum chloride solution treatment, specifically modifies the diatomaceous earth pores, removing impurities and controlling the pore size to 20-50 nm, improving its adsorption capacity for free water and promoting full cement hydration to reduce porosity. Step B, the silane coupling agent reflux reaction, ensures that hydrophobic groups are uniformly grafted onto the inner and outer surfaces of the pores. This process enables diatomaceous earth to both optimize the matrix microstructure through pore adsorption and block water penetration through hydrophobic modification, forming a "microporous adsorption + surface hydrophobicity" impermeability system in synergy with modified perlite, thereby effectively improving the impermeability of the floor slab.

[0019] Optionally, in step A, the mass concentration of the aluminum chloride solution is 8%-12%; the mass ratio of the diatomaceous earth to the aluminum chloride solution is 1:(6-8).

[0020] By adopting the above technical solution, the above ratio can ensure that aluminum chloride fully enters the diatomite pores and undergoes a hydrolysis reaction. The generated aluminum hydroxide precipitate can precisely control the pore size, avoiding insufficient modification due to too low a concentration or pore blockage due to too high a concentration.

[0021] Optionally, in step B, the mass concentration of the silane coupling agent KH-570 solution is 2%-4%; the mass ratio of the pore-modified diatomaceous earth to the silane coupling agent KH-570 solution is 1:(4-6).

[0022] Secondly, this application provides a method for preparing aerated concrete floor decking, employing the following technical solution: A method for preparing aerated concrete floor decking includes the following steps: S1. Mix cement, fly ash, mortar, gypsum paste, metakaolin, modified expanded perlite, composite modified diatomaceous earth, and composite fiber for 3-5 minutes to obtain dry mix. Then add water-reducing agent, foam stabilizer, air-generating agent, and water, and continue mixing for 3-5 minutes to obtain aerated concrete. S2. Place a steel mesh cage in the floor slab mold beforehand, then inject the aerated concrete into the floor slab mold, vibrate to compact, and let it stand for 5-7 hours to generate gas; then send it into an autoclave, pre-cur it at 60-80℃ for 2-3 hours, then raise the temperature to 180-200℃ and cure it for 9-13 hours, cool it to room temperature, and demold to obtain the aerated concrete floor deck.

[0023] By adopting the above technical solution and the above method, the aerated concrete floor deck has stable impermeability and fire resistance. The curing time ensures the interface fusion of the modified components and cementitious materials, so that the floor deck strength and impermeability remain stable.

[0024] This application also provides an application of aerated concrete floor decking, employing the following technical solution: An application of aerated concrete floor decking, wherein the aerated concrete floor decking is used as a non-load-bearing floor slab in civil buildings or an auxiliary load-bearing floor slab in industrial buildings, wherein a 5-10mm expansion joint is reserved between the floor slabs and the joint is filled with elastic sealant.

[0025] The clearly defined application scenarios and installation parameters of the above-mentioned solution ensure the effective performance of the floor slab's impermeability and fire resistance. The design, tailored to non-load-bearing and auxiliary load-bearing applications, matches the floor slab's performance characteristics. The 5-10mm expansion joints and elastic sealant absorb stress caused by the floor slab's drying shrinkage and temperature deformation, preventing cracks and blocking seepage paths. The elastic sealant also possesses fire-resistant properties, preventing the spread of flames through the joints. This application design allows the floor slab to fully demonstrate its impermeability and fire resistance in actual use, avoiding performance degradation due to improper installation and expanding its application range in civil and industrial buildings.

[0026] Aerated concrete (ACP) floor decks have pre-drilled grooves along their long sides for laying reinforcing cages or trusses in the main load-bearing direction. Reinforcing bars or mesh are then laid on top, followed by the pouring of concrete to form a cast-in-place composite floor slab. This replaces existing precast concrete composite slabs, forming an integral composite floor slab with the cast-in-place concrete, offering excellent thermal insulation and soundproofing performance. Compared to traditional floor slab construction methods, which involve long construction cycles and high consumption of reusable materials with full-span scaffolding support, require non-removable formwork for the floor deck and necessitate additional ceiling construction, increasing costs, and precast composite slabs are heavy, require specialized cranes, and are expensive, the ACP floor decks described in this application effectively avoid these drawbacks, balancing construction convenience, economy, and performance, further enhancing their application value.

[0027] In summary, this application has the following beneficial effects: 1. This application effectively solves the problem of poor impermeability of aerated concrete (APC) floor decks by introducing a dual-modification component of "modified expanded perlite + composite modified diatomaceous earth" for synergistic effect. The mortar fills the cement hydration pores, while metakaolinite activates fly ash to generate more CSH gel, reducing the internal porosity of the matrix. After composite modification, the expanded perlite exhibits improved interfacial bonding with the cementitious material, the EVA resin film seals interfacial micro-cracks, and nano-silica reinforces and blocks seepage channels. The composite modified diatomaceous earth, through stepwise modification, both adsorbs free water to promote hydration and imparts hydrophobicity, forming a gradient hydrophobic barrier in synergy with perlite. This dual protection effectively reduces the interconnected porosity of the matrix, significantly enhances the impermeability of the floor deck, prevents moisture penetration from affecting the indoor environment and material degradation, and provides crucial assurance for the stable application of APC floor decks in buildings.

[0028] 2. This application achieves dual protection through component optimization, forming a "high-temperature barrier + structural support," effectively improving the fire resistance of aerated concrete floor decks. Metakaolin undergoes a phase transformation at high temperatures to generate structurally stable mullite crystals, forming a dense protective layer on the material surface to hinder heat transfer. The basalt fibers in the composite fibers have a fire resistance temperature exceeding 800℃, maintaining structural support capacity during fires. The polyacrylonitrile-based carbon fibers slowly carbonize to form a carbon skeleton, synergistically maintaining structural integrity with hydration products. This dual protection mechanism effectively solves the hidden danger of floor decks collapsing due to a sharp decrease in strength at high temperatures, ensuring that the floor deck maintains a certain degree of structural stability under high-temperature environments such as fires, improving building safety, and providing a reliable solution for the application of aerated concrete floor decks in the field of building fire protection.

[0029] 3. This application, while enhancing impermeability and fire resistance, precisely safeguards the original core advantages of aerated concrete floor decking and expands its application scope. Modified expanded perlite and composite modified diatomaceous earth retain their lightweight and porous characteristics, forming uniform closed pores with the help of a foaming agent, resulting in floor decking thermal insulation performance superior to traditional concrete. The three-dimensional network structure of composite fibers synergistically enhances sound wave absorption efficiency and ensures sound insulation performance. Simultaneously, the reinforcing effects of mortar, metakaolin, and composite fibers compensate for the strength shortcomings of lightweight materials, ensuring the floor deck strength meets the requirements for non-load-bearing and auxiliary load-bearing floor decking. Furthermore, the extensive use of fly ash in the raw materials realizes the resource utilization of industrial waste, the synergistic design of the dual modified components reduces costs, and the preparation process is compatible with existing equipment, providing a feasible path for the large-scale promotion and application of aerated concrete floor decking. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments.

[0031] Preparation example of modified expanded perlite Preparation Example 1 Modified expanded perlite was prepared using the following method: (1) Mix silane coupling agent KH-550, EVA resin powder and 96% ethanol aqueous solution at a mass ratio of 3:2:90 and stir for 10 min to obtain composite modifier; (2) The expanded perlite was placed in an 80℃ oven and dried for 4 hours. Then the dried expanded perlite was immersed in a composite modifier. The mass ratio of the dried expanded perlite to the composite modifier was 1:4. Then it was ultrasonically treated at 50℃ for 60 minutes. After filtration, it was dried at 110℃ for 4 hours to obtain active expanded perlite. The active expanded perlite was then mixed and stirred with a nano silica dispersion for 1 hour. The mass concentration of the nano silica dispersion was 12%, and the mass ratio of the active expanded perlite to the nano silica dispersion was 1:3. After stirring, the mixture was filtered and the solid phase was dried to obtain modified expanded perlite.

[0032] Preparation Example 2 Modified expanded perlite was prepared using the following method: (1) Mix silane coupling agent KH-550, EVA resin powder and 96% ethanol aqueous solution in a mass ratio of 4.5:3:92 and stir for 20 min to obtain composite modifier; (2) The expanded perlite was placed in a 90℃ oven and dried for 3 hours. Then the dried expanded perlite was immersed in a composite modifier. The mass ratio of the dried expanded perlite to the composite modifier was 1:5. Then it was ultrasonically treated at 55℃ for 45 minutes. After filtration, it was dried at 120℃ for 3 hours to obtain active expanded perlite. The active expanded perlite was then mixed and stirred with a nano silica dispersion for 1.5 hours. The mass concentration of the nano silica dispersion was 14%, and the mass ratio of the active expanded perlite to the nano silica dispersion was 1:4. After stirring, the mixture was filtered and the solid phase was dried to obtain modified expanded perlite.

[0033] Preparation Example 3 Modified expanded perlite was prepared using the following method: (1) Mix silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution with a mass concentration of 96% at a mass ratio of 6:4:95 and stir for 30 min to obtain a composite modifier; (2) The expanded perlite was placed in a 100℃ oven and dried for 2 hours. Then the dried expanded perlite was immersed in a composite modifier. The mass ratio of the dried expanded perlite to the composite modifier was 1:6. Then it was ultrasonically treated at 60℃ for 30 minutes. After filtration, it was dried at 130℃ for 2 hours to obtain active expanded perlite. The active expanded perlite was then mixed and stirred with a nano silica dispersion for 2 hours. The mass concentration of the nano silica dispersion was 16%, and the mass ratio of the active expanded perlite to the nano silica dispersion was 1:5. After stirring, the mixture was filtered and the solid phase was dried to obtain modified expanded perlite.

[0034] Preparation example of composite modified diatomite Preparation Example 4 Composite modified diatomaceous earth was prepared using the following method: A. Mix 10 kg of diatomaceous earth with 60 kg of aluminum chloride solution with a mass concentration of 8%, stir and react at 70°C for 3 h, filter, wash with deionized water until neutral, and dry to constant weight to obtain pore-modified diatomaceous earth. B. Immerse 10 kg of pore-modified diatomaceous earth in 40 kg of 2% KH-570 silane coupling agent solution, reflux for 1 h, cool and filter, and dry to obtain composite modified diatomaceous earth.

[0035] Preparation Example 5 Composite modified diatomaceous earth was prepared using the following method: A. Mix 10 kg of diatomaceous earth with 70 kg of 10% aluminum chloride solution, stir and react at 75°C for 2.5 h, filter, wash with deionized water until neutral, and dry to constant weight to obtain pore-modified diatomaceous earth. B. Immerse 10 kg of pore-modified diatomaceous earth in 50 kg of 3% KH-570 silane coupling agent solution, reflux for 1.5 h, cool and filter, and dry to obtain composite modified diatomaceous earth.

[0036] Preparation Example 6 Composite modified diatomaceous earth was prepared using the following method: A. Mix 10 kg of diatomaceous earth with 80 kg of 12% aluminum chloride solution, stir and react at 80°C for 2 h, filter, wash with deionized water until neutral, and dry to constant weight to obtain pore-modified diatomaceous earth. B. Immerse 10 kg of pore-modified diatomaceous earth in 60 kg of 4% KH-570 silane coupling agent solution, reflux for 2 h, cool and filter, and dry to obtain composite modified diatomaceous earth.

[0037] Preparation Example 7 The difference between the composite modified diatomaceous earth and preparation example 6 is that the mass concentration of the aluminum chloride solution used in step A of this preparation example is 15%.

[0038] Mortar preparation: Sand is selected as the siliceous material and ground into 100-120 mesh in a ball mill. Water is added at a solid-liquid mass ratio of 2:1 and stirred in a mixing device for 15 minutes to obtain a uniform, particle-free mortar with good fluidity for later use.

[0039] Preparation of gypsum slurry: Select gypsum as a hydration regulator, add water at a solid-liquid mass ratio of 1:0.7~0.9, stir until it becomes a paste, and stir throughout the process without any lumps to obtain a uniform gypsum slurry for later use.

[0040] Example Example 1 An aerated concrete floor deck includes an aerated concrete slab and a steel mesh cage embedded in the aerated concrete slab for load-bearing. The raw material composition and proportion of the aerated concrete slab are shown in Table 1. The modified expanded perlite is the modified expanded perlite prepared in Preparation Example 1, and the composite modified diatomite is the composite modified diatomite prepared in Preparation Example 4. The composite fiber is composed of basalt fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 2:1. The length of the basalt fiber is 3 mm, the length of the polyacrylonitrile-based carbon fiber is 1 mm, and the gas generating agent is aluminum powder paste.

[0041] An aerated concrete floor deck is prepared by the following method: S1. Mix cement, fly ash, mortar, gypsum paste, metakaolin, modified expanded perlite, composite modified diatomaceous earth, and composite fiber for 3 minutes to obtain dry mix. Then add water-reducing agent, foam stabilizer, air-generating agent, and water, and continue mixing for 3 minutes to obtain aerated concrete. S2. Place a steel mesh cage in the floor slab mold beforehand, then inject the aerated concrete into the floor slab mold, vibrate to compact, and let it stand for 5 hours to generate gas; then send it into an autoclave, pre-cur it at 60℃ for 2 hours, then raise the temperature to 180℃ and cure it for 9 hours, cool it to room temperature, and demold to obtain the aerated concrete floor deck.

[0042] It should be noted that, in addition to the method of directly adding composite fibers to the raw material ratio in this embodiment, the improvement of toughness and flexural strength can also be achieved by pre-embedding fiber cloth in the aerated concrete slab. The preparation processes of the two methods are different, and the specific differences are as follows: When using the fiber cloth pre-embedding method, in step S2, the steel mesh cage is first placed in the floor slab mold, and then the fiber cloth is fixed on the steel mesh cage according to the design position to ensure that the fiber cloth is tightly attached to the steel mesh cage and the position is accurate. Then, aerated concrete is injected, and the subsequent vibration, aeration, autoclaving and other steps are the same as in this embodiment. However, in the fiber addition method in this embodiment, it is only necessary to mix the composite fibers with other dry materials evenly in step S1, without the need for additional pre-embedding and fixing procedures.

[0043] Example 2 An aerated concrete floor deck includes an aerated concrete slab and a steel mesh cage embedded in the aerated concrete slab for load-bearing. The raw material composition and formula of the aerated concrete slab are shown in Table 1. The modified expanded perlite is the modified expanded perlite prepared in Preparation Example 2, the composite modified diatomite is the composite modified diatomite prepared in Preparation Example 5, the composite fiber is composed of basalt fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 3.5:1, the length of the basalt fiber is 2 mm, the length of the polyacrylonitrile-based carbon fiber is 2 mm, and the gas generating agent is aluminum powder paste.

[0044] An aerated concrete floor deck is prepared by the following method: S1. Mix cement, fly ash, mortar, gypsum paste, metakaolin, modified expanded perlite, composite modified diatomaceous earth, and composite fiber for 4 minutes to obtain dry mix. Then add water-reducing agent, foam stabilizer, air-generating agent, and water, and continue mixing for 4 minutes to obtain aerated concrete. S2. Place a steel mesh cage in the floor slab mold beforehand, then inject the aerated concrete into the floor slab mold, vibrate and compact it, and let it stand for 6 hours to generate gas; then send it into an autoclave, pre-cur it at 70℃ for 2.5 hours, then raise the temperature to 190℃ and cure it for 11 hours, cool it to room temperature, and demold to obtain the aerated concrete floor slab.

[0045] Example 3 An aerated concrete floor deck includes an aerated concrete slab and a steel mesh cage embedded in the aerated concrete slab for load-bearing. The raw material composition and proportions of the aerated concrete slab are shown in Table 1. The modified expanded perlite is selected from the modified expanded perlite prepared in Preparation Example 3, and the composite modified diatomite is selected from the composite modified diatomite prepared in Preparation Example 6. The composite fiber is composed of basalt fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 5:1. The length of the basalt fiber is 1 mm, the length of the polyacrylonitrile-based carbon fiber is 3 mm, and the gas generating agent is aluminum powder paste.

[0046] An aerated concrete floor deck is prepared by the following method: S1. Mix cement, fly ash, mortar, gypsum paste, metakaolin, modified expanded perlite, composite modified diatomaceous earth, and composite fiber for 5 minutes to obtain dry mix. Then add water-reducing agent, foam stabilizer, air-generating agent, and water, and continue mixing for 5 minutes to obtain aerated concrete. S2. Place a steel mesh cage in the floor slab mold beforehand, then inject the aerated concrete into the floor slab mold, vibrate to compact, and let it stand for 7 hours to generate gas; then send it into an autoclave, pre-cur it at 80°C for 3 hours, then raise the temperature to 200°C and cure it for 13 hours, cool it to room temperature, and demold to obtain the aerated concrete floor slab.

[0047] Table 1. Raw material composition and proportions (kg) of aerated concrete floor decking in Examples 1-3

[0048] Example 4 An aerated concrete floor deck differs from Example 2 in that the air-generating agent in this example is sodium fatty alcohol alkyl sulfonate.

[0049] Example 5 An aerated concrete floor deck differs from Example 2 in that the composite modified diatomaceous earth used in this example is the composite modified diatomaceous earth prepared in Preparation Example 7.

[0050] Example 6 An aerated concrete floor deck differs from Example 2 in that the composite fiber in this example is composed of basalt fiber and polyacrylonitrile-based carbon fiber in a mass ratio of 1:1.

[0051] Comparative Example Comparative Example 1 Aerated concrete was prepared according to the embodiments in the application document with publication number CN120774735A entitled "An Aerated Concrete Applied to Floor Slab Sound Insulation and Thermal Insulation and Its Preparation Method Thereof", and then aerated concrete floor deck was obtained.

[0052] Comparative Example 2 An aerated concrete floor deck differs from Example 2 in that, in the aerated concrete raw materials of this comparative example, an equal amount of untreated expanded perlite is used instead of modified expanded perlite.

[0053] Comparative Example 3 An aerated concrete floor deck differs from Example 2 in that, in the aerated concrete raw materials of this comparative example, an equal amount of unmodified diatomaceous earth is used instead of composite modified diatomaceous earth.

[0054] Comparative Example 4 An aerated concrete floor deck differs from Example 2 in that no composite fibers are added to the aerated concrete raw materials in this comparative example.

[0055] Performance testing The aerated concrete floor deckings prepared in Examples 1-6 and Comparative Examples 1-4 were cut into standard specimens for performance testing. The strength loss rate test method was as follows: the specimens were placed in a high-temperature furnace and heated to 600℃ at a rate of 10℃ / min. After holding at that temperature for 2 hours, they were naturally cooled to room temperature. The compressive strength of the cooled specimens was tested using a pressure testing machine and compared with the compressive strength of specimens from the same batch at room temperature (20℃) to calculate the strength loss rate. The relevant test results are shown in Table 2.

[0056] Table 2 Test Results

[0057] As shown in Table 2, the flexural strength values ​​of Examples 1-6 of this application are all in the range of 2.51-2.78 MPa, significantly better than Comparative Example 1 (1.23 MPa) and Comparative Example 4 (1.87 MPa), with Example 2 reaching a peak strength of 2.78 MPa. In the technical solution of this application, the CSH gel generated by filling cement hydration pores with mortar and activating fly ash with metakaolin enhances the density from within the matrix. In the composite fibers, basalt fibers bridge microcracks, and polyacrylonitrile-based carbon fibers fill pores to form a three-dimensional support network; both work together to compensate for the strength shortcomings of lightweight materials. Comparative Examples 2-3, lacking modified perlite or diatomaceous earth, exhibited decreased interfacial bonding strength, with flexural strengths only ranging from 2.13 to 2.17 MPa, further confirming the auxiliary value of the dual-modification system in improving strength.

[0058] As shown in Table 2, the anti-seepage pressure data clearly demonstrates the outstanding effect of the "modified expanded perlite + composite modified diatomite" dual-modification system. The anti-seepage pressure of Examples 1-6 is ≥0.87MPa, and Example 2 reaches 1.05MPa, which is 200% higher than Comparative Example 1 (0.35MPa) and 133%-150% higher than Comparative Examples 2-3 (0.42-0.45MPa). After treatment with EVA resin and nano-silica, the micro-cracks at the interface of the modified expanded perlite are effectively sealed, while the composite modified diatomite forms a gradient barrier through "aluminum chloride pore adsorption + KH-570 hydrophobic modification". The dual effect significantly reduces the interconnected porosity. In Example 5, the high aluminum chloride concentration (15%) caused blockage of the diatomaceous earth pores, and the anti-seepage pressure dropped to 0.87 MPa, confirming the necessity of the preferred range of aluminum chloride concentration in the technical solution. In contrast, in Comparative Examples 2-3, the porous structure of traditional perlite and diatomaceous earth became a water seepage channel because no modified components were used, resulting in a significant reduction in anti-seepage performance.

[0059] The strength loss rate data clearly reflects the fire resistance advantages of the aerated concrete floor decking of this application. The strength loss rates of Examples 1-6 after reaching 600℃ were only 10.6%-13.5%, far lower than Comparative Example 1 (55.7%), Comparative Example 2 (42.3%), and Comparative Example 3 (40.1%). This result stems from the mullite crystals generated during the high-temperature phase transformation of metakaolinite, which form a dense protective layer on the material surface to hinder heat transfer; the basalt fibers (fire-resistant above 800℃) in the composite fibers maintain structural support, while the polyacrylonitrile-based carbon fibers slowly carbonize to form a continuous carbon skeleton; both work synergistically to suppress high-temperature strength decay.

[0060] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An aerated concrete floor deck, characterized in that, This includes aerated concrete panels and steel mesh cages embedded within the aerated concrete panels for load-bearing purposes. The aerated concrete panel comprises raw materials with the following components: The ingredients are: 30-50 parts cement, 20-30 parts fly ash, 5-12 parts mortar, 10-18 parts modified expanded perlite, 5-10 parts composite modified diatomaceous earth, 5-15 parts metakaolin, 3-8 parts composite fiber, 3-8 parts gypsum paste, 0.3-1.2 parts foaming agent, 0.1-0.5 parts foam stabilizer, 0.5-2.0 parts water-reducing agent, and 30-50 parts water. The modified expanded perlite is obtained by modifying expanded perlite with a composite modifier, which includes silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution. The composite modified diatomaceous earth is obtained by stepwise modification of diatomaceous earth with aluminum chloride and silane coupling agent KH-570.

2. The aerated concrete floor decking according to claim 1, characterized in that: The composite fiber is composed of basalt fiber and polyacrylonitrile-based carbon fiber in a mass ratio of (2-5):1, with the basalt fiber having a length of 1-3 mm and the polyacrylonitrile-based carbon fiber having a length of 1-3 mm.

3. An aerated concrete floor deck according to claim 1, characterized in that, The modified expanded perlite was prepared using the following method: (1) Mix silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution, and stir for 10-30 min to obtain composite modifier; (2) Place the expanded perlite in an oven at 80-100℃ and dry for 2-4 hours. Then, immerse the dried expanded perlite in a composite modifier and sonicate it at 50-60℃ for 30-60 minutes. After filtration, dry it at 110-130℃ to obtain active expanded perlite. Then, mix the active expanded perlite with a nano silica dispersion and stir for 1-2 hours. After filtration, take the solid phase and dry it to obtain modified expanded perlite.

4. An aerated concrete floor deck according to claim 3, characterized in that, In step (1), the mass ratio of silane coupling agent KH-550, EVA resin powder and ethanol aqueous solution is (3-6):(2-4):(90-95); the mass concentration of ethanol aqueous solution is 92%-96%.

5. An aerated concrete floor deck according to claim 3, characterized in that, In step (2), the mass ratio of dried expanded perlite to composite modifier is 1:(4-6); the mass concentration of nano silica dispersion is 12%-16%, and the mass ratio of active expanded perlite to nano silica dispersion is 1:(3-5).

6. An aerated concrete floor deck according to claim 1, characterized in that, The composite modified diatomaceous earth was prepared using the following method: A. Mix diatomaceous earth with aluminum chloride solution, stir and react at 70-80℃ for 2-3 hours, filter, wash until neutral, and dry to obtain pore-modified diatomaceous earth; B. Immerse the pore-modified diatomaceous earth in a solution of silane coupling agent KH-570, reflux for 1-2 hours, cool and filter, and dry to obtain composite modified diatomaceous earth.

7. An aerated concrete floor deck according to claim 6, characterized in that: In step A, the mass concentration of the aluminum chloride solution is 8%-12%; the mass ratio of the diatomaceous earth to the aluminum chloride solution is 1:(6-8).

8. An aerated concrete floor deck according to claim 6, characterized in that: In step B, the mass concentration of the silane coupling agent KH-570 solution is 2%-4%; the mass ratio of the pore-modified diatomaceous earth to the silane coupling agent KH-570 solution is 1:(4-6).

9. A method for preparing aerated concrete floor decking according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Mix cement, fly ash, mortar, gypsum paste, metakaolin, modified expanded perlite, composite modified diatomaceous earth, and composite fiber for 3-5 minutes to obtain dry mix. Then add water-reducing agent, foam stabilizer, air-generating agent, and water, and continue mixing for 3-5 minutes to obtain aerated concrete. S2. Place a steel mesh cage in the floor slab mold beforehand, then inject the aerated concrete into the floor slab mold, vibrate to compact, and let it stand for 5-7 hours to generate gas; then send it into an autoclave, pre-cur it at 60-80℃ for 2-3 hours, then raise the temperature to 180-200℃ and cure it for 9-13 hours, cool it to room temperature, and demold to obtain the aerated concrete floor deck.

10. An application of the aerated concrete floor decking according to any one of claims 1-8, characterized in that, The aerated concrete floor deck is used as a non-load-bearing floor slab in civil buildings or an auxiliary load-bearing floor slab in industrial buildings. When using it, a 5-10mm expansion joint is reserved between the floor slabs and the joint is filled with elastic sealant.

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