Lightweight high-strength concrete thermal insulation wallboard for high-rise building and preparation method thereof

Abstract

The invention discloses a lightweight high-strength concrete thermal insulation wallboard for a high-rise building and a preparation method of the lightweight high-strength concrete thermal insulation wallboard. The lightweight high-strength concrete thermal insulation wallboard comprises the following raw materials in parts by weight: 300-500 parts of cement, 60-90 parts of slag powder, 60-100 parts of silica fume, 60-90 parts of microbeads, 100-200 parts of floating beads, 500-900 parts of modified lightweight aggregate, 15-20 parts of alkali-resistant glass fibers, 25-40 parts of a water reducing agent and 180-220 parts of water. According to the invention, a layer of'hard shell 'is formed on the surface after the shale ceramsite is wrapped and reinforced by the light cement paste, the problem of high water absorption rate of the shale ceramsite is improved, meanwhile, the mechanical property of the shale ceramsite is improved, secondly, the self-made lightweight aggregate is low in water absorption rate and high in strength, the density of the self-made lightweight aggregate is close to that of a gelling matrix of the thermal insulation wallboard, and the aggregate can be prevented from floating or sinking; the floating beads are added into the modified lightweight aggregate, so that the prepared lightweight wallboard is good in homogeneity, low in water absorption and good in mechanical property, the weight of the wallboard can be reduced through cooperation of the floating beads in the thermal insulation wallboard and the modified lightweight aggregate, meanwhile, the floating beads have excellent fire resistance and heat insulation performance, and the heat insulation and fire resistance of the lightweight wallboard can be improved through cooperation of the floating beads and the alkali-resistant glass fibers with the high melting temperature.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings and its preparation method. Background Technology

[0002] Precast wall panels offer advantages such as factory prefabrication, simplified construction procedures, reduced on-site wet work, good overall integrity, improved working conditions, and increased labor productivity. With rising building energy efficiency standards, and higher performance requirements for integrated thermal insulation and decorative exterior walls in high-rise buildings, higher demands are placed on precast insulated wall panels for high-rise buildings in terms of thermal insulation, fire resistance, durability, and mechanical strength.

[0003] To improve the performance of precast wall panels, existing technologies have attempted to modify them: Chinese patent CN116044087A, which utilizes glass microspheres and straw fibers to address the issues of high concrete density and improve thermal insulation performance, suffers from a compressive strength of less than 10 MPa, failing to meet the requirements of the extreme environments, complex loads, and functional demands of high-rise buildings. Chinese patent CN111908845A utilizes ultra-high performance concrete to prepare RPC lightweight insulation boards, but the high density of RPC boards does not meet the requirements for lightweight insulation. CN111848213A, which uses aluminum powder foaming, reduces the mechanical strength of concrete and increases the water absorption rate of the wall panel. Traditional concrete exterior wall construction methods can no longer meet the design requirements of high-rise buildings, necessitating the exploration and research of new precast exterior wall preparation technologies to meet the energy-saving requirements of modern buildings. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings mentioned above by providing a lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings and its preparation method.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a lightweight high-strength concrete thermal insulation wall panel for high-rise buildings, comprising the following raw materials in parts by weight: 300-500 parts cement, 60-90 parts slag powder, 60-100 parts silica fume, 60-90 parts microspheres, 100-200 parts cenospheres, 500-900 parts modified lightweight aggregate, 15-20 parts alkali-resistant glass fiber, 25-40 parts water-reducing agent, and 180-220 parts water.

[0006] Furthermore, the cement is P I or P One of the types of O 52.5 cement; The slag powder is S105 slag powder; The silica fume has a specific surface area ≥23000m² / kg, SiO2 content ≥95%, 28d activity index ≥95%, and water requirement ratio ≤110%.

[0007] Furthermore, the microspheres are fly ash microspheres with a specific surface area ≥1200m² / kg, a median diameter of 1.8~2.3μm, a 28d activity index ≥75%, and a water requirement ratio ≤95%.

[0008] Furthermore, the microspheres are thin-walled hollow glass microspheres extracted from fly ash, with a mass ratio of 40-100 mesh and 20-40 mesh of 1:(2-5), and a true density of 0.60-0.70 g / cm³.

[0009] Furthermore, the alkali-resistant glass fiber has a density ≤2.7g / cm³, a softening point ≥850℃, and a melting temperature ≥1500℃.

[0010] Furthermore, the water-reducing agent is a polycarboxylate water-reducing agent with a water reduction rate of 25-40% and a solid content of 30-40%.

[0011] Furthermore, the modified lightweight aggregate has an apparent density of 1.60~1.70 g / cm³, a particle size of 0~5 mm, and a 24h water absorption rate of ≤3%.

[0012] Furthermore, the modified lightweight aggregate is made by mixing shale ceramsite and active slurry at a mass ratio of 3 to 6:1, followed by modification, strengthening, and curing.

[0013] Furthermore, the apparent density of the shale ceramsite is 1.3-1.5 g / cm³, the particle size is 0-3 mm, and the water absorption rate is ≤15% after 24 hours. The active slurry is composed of 80-100 parts cement, 15-20 parts silica fume, 10-15 parts cenospheres, 15-20 parts water, and 0.5-2 parts polycarboxylate superplasticizer.

[0014] Another technical solution adopted in this invention is a method for preparing lightweight, high-strength concrete thermal insulation wall panels for high-rise buildings, comprising the following steps: S1. Weigh each raw material according to the weight parts. First, add cement, slag powder, silica fume, microspheres, and cenospheres to the mixer and stir at 100-150 rpm for 3-5 minutes until a uniform dry powder state is reached. Then, dissolve the polycarboxylate superplasticizer in water to form a solution and add it in two parts. The first time, add 70% of the solution and stir at 200 rpm for 2 minutes to form a uniform slurry. The second time, add the remaining 30% of the solution and simultaneously add alkali-resistant glass fiber slowly and stir at 250 rpm for 1 minute to avoid fiber clumping. Finally, a fluid slurry with uniformly dispersed fibers is formed. S2. Immerse the shale ceramsite into the S1 slurry and stir it with a paddle mixer at 80 rpm for 8 minutes to ensure that the slurry fully coats the surface of the aggregate. Then, sieve it through a 5 mm vibrating screen to remove excess slurry and retain the aggregate with a surface slurry coating thickness of 1-2 mm. This process forms a "shell-core" structure. S3. Place the aggregate soaked and screened in S2 into an accelerated curing chamber for curing. The temperature of the curing chamber is 60-90℃ and the curing time is 6-8 hours to obtain the lightweight high-strength concrete insulation wall panel.

[0015] The beneficial effects of this invention are reflected in: This invention utilizes shale ceramsite encapsulated and reinforced in lightweight cement slurry, forming a "hard shell" on its surface. This improves the high water absorption rate of shale ceramsite and enhances its mechanical properties. Furthermore, the self-made lightweight aggregate in this invention has low water absorption and high strength, with a density similar to the cementitious matrix of the insulation wall panel. This prevents the aggregate from floating or sinking, resulting in lightweight wall panels with good homogeneity, low water absorption, and excellent mechanical properties. Additionally, the cenospheres in the insulation wall panel can synergistically modify the lightweight aggregate to reduce the wall panel's weight. The cenospheres also possess excellent fire resistance and thermal insulation properties, which, combined with alkali-resistant glass fibers with high melting temperatures, further enhance the thermal insulation and fire resistance of the lightweight wall. Finally, the prefabricated insulation wall panel of this invention is formaldehyde-free and asbestos-free, does not produce needle-like dust or toxic volatile gases, and contains no other harmful components. It also boasts high tensile strength, low water absorption, no efflorescence, and is environmentally friendly and healthy. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This invention discloses a lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings, comprising the following raw materials in parts by weight: 300-500 parts cement, 60-90 parts slag powder, 60-100 parts silica fume, 60-90 parts microspheres, 100-200 parts cenospheres, 500-900 parts modified lightweight aggregate, 15-20 parts alkali-resistant glass fiber, 25-40 parts water-reducing agent, and 180-220 parts water.

[0018] The innovation of this application lies in resolving the contradiction between lightweight, high strength, and thermal insulation performance by optimizing the raw material ratio system. Compared with the existing technology that relies on a single component to improve a certain aspect of performance, this embodiment achieves high mechanical properties while maintaining low density through the rational combination of multiple raw materials. Furthermore, the introduction of fiber reinforcement and water-reducing agents optimizes structural integrity and workability, thereby meeting the comprehensive performance requirements of prefabricated insulated wall panels for high-rise buildings.

[0019] The working principle of this application embodiment is as follows: By optimizing the raw material ratio system, a synergistic improvement in lightweight, high strength, and thermal insulation performance is achieved. Cement, as the basic cementitious material, provides the main strength; slag powder assists in the hydration reaction, enhancing the later strength stability; silica fume fills the micropores, improving the matrix density. Furthermore, the introduction of microspheres and cenospheres significantly reduces the overall density while contributing excellent thermal insulation effects; the hollow structure of the cenospheres further enhances the thermal insulation function. Modified lightweight aggregate, while maintaining low density characteristics, improves the interfacial bonding strength with the matrix through modification treatment, thereby improving overall mechanical properties. Alkali-resistant glass fiber dispersed in the slurry effectively inhibits crack propagation and enhances impact toughness. The addition of water-reducing agent optimizes slurry fluidity, reduces water consumption, and thus improves the strength of the hardened body. Water, as the reaction medium, ensures the full hydration process. Thus, by combining the raw materials in specific proportions, the lightweight components work together to achieve the requirements of low density and thermal insulation, while the cementing system and reinforcing components work together to ensure high strength. This results in a concrete wall panel structure that is both lightweight and high-strength, with excellent thermal insulation performance. This solves the technical problem that prefabricated insulated wall panels in high-rise buildings cannot simultaneously meet the requirements of lightweight, high strength, and good thermal insulation performance.

[0020] This application further proposes that the cement is P I or P O 52.5 cement is one of the following: the slag powder is S105 slag powder; the specific surface area of ​​silica fume is ≥23000m² / kg, the SiO2 content is ≥95%, the 28d activity index is ≥95%, and the water requirement ratio is ≤110%.

[0021] Specifically, cement refers to the main cementing material used in the preparation of concrete wall panels, and can be P... I. Silicate cement or P Ordinary Portland cement is used. The selection of these two types of cement aims to provide excellent early and late strength development, ensuring the wall panels can withstand the complex loads of high-rise buildings. Slag powder refers to a highly active admixture, which can be S105 grade slag powder. Its purpose is to participate in the secondary hydration reaction to generate more cementitious substances, thereby improving the long-term strength and crack resistance of concrete, while reducing cement usage to lower the heat of hydration. In practical applications, silica fume refers to an ultrafine mineral admixture, which can be made from materials with a specific surface area ≥23000m² / kg and SiO2 content ≥95%. Its purpose is to significantly enhance the mechanical properties of concrete by filling micropores and promoting the formation of additional CSH gel through pozzolanic reaction.

[0022] Specifically, the above solution effectively ensures the high strength and stability of the concrete wall panel by precisely specifying the material and performance parameters of cement, slag powder, and silica fume. In practical operation, P is selected. I or P O52.5 cement generates denser hydration products, significantly enhancing the interfacial bond between the matrix and lightweight aggregate, thus preventing structural failure due to insufficient strength. Using S105 slag powder, with its high activity index, ensures its effective participation in secondary hydration reactions, generating more cementitious substances and improving the long-term strength and crack resistance of concrete. Simultaneously, it reduces cement usage to lower the heat of hydration and prevent temperature stress-induced cracking. For silica fume, a limited high specific surface area increases the reactive interface, high SiO2 content ensures purity and pozzolanic reaction efficiency, a high 28-day activity index directly contributes to strength gain, and a low water demand ratio improves the fluidity of the mixture and reduces water consumption. The synergistic effect of these parameters allows silica fume to effectively compensate for the strength loss caused by lightweight aggregate, achieving a balance between lightweight and high strength. In summary, the above technical solution addresses the performance defects caused by material uncertainties in the basic formula by optimizing the performance parameters of key components, thus meeting the comprehensive requirements of high-rise buildings for high strength, lightweight, and thermal insulation performance.

[0023] This application further specifies that the microspheres are fly ash microspheres with a specific surface area ≥1200m² / kg, a median diameter of 1.8~2.3μm, a 28d activity index ≥75%, and a water requirement ratio ≤95%.

[0024] Specifically, microspheres refer to an industrial byproduct with lightweight properties and potential pozzolanic activity, which can be achieved using fly ash microspheres. In practical applications, specific surface area refers to the contact area between the surface of the microsphere particles and a unit mass of material, which can be achieved by selecting high-fineness fly ash microspheres to meet the requirement of not less than 1200 m² / kg. Median diameter refers to the particle size value corresponding to a cumulative mass percentage of 50% in the particle size distribution, which can be controlled within the range of 1.8~2.3 μm by optimizing the grading process of fly ash microspheres. Furthermore, the 28-day activity index refers to the ability of microspheres to participate in secondary hydration reactions during the curing stage, which can be ensured to reach above 75% by adjusting the chemical composition and heat treatment process of the fly ash microspheres. Water demand ratio refers to the degree of water requirement of the microspheres in the concrete system, which can be controlled below 95% by reducing the surface water absorption characteristics of the microspheres.

[0025] In detail, the above technical solution systematically solves the performance defects caused by mismatched properties by precisely defining the core parameters of the microspheres. The selection of fly ash microspheres is based on their inherent lightweight properties and potential pozzolanic activity, which can effectively reduce the overall density of the wall panel and participate in the cementitious reaction, thereby supporting the goal of synergistic improvement in lightweighting and strength. The setting of specific surface area significantly expands the interaction interface between the microspheres and the cement matrix, significantly promoting the generation rate and uniform distribution of hydration products, overcoming the problem of weakened interfacial bonding caused by insufficient surface area in traditional microspheres, and thus strengthening the microstructural density of concrete. Strict control of the median diameter enables refined regulation of particle size distribution, avoiding stress concentration effects caused by coarse particles and fluidity loss caused by fine particles, ensuring that the slurry maintains a stable dispersion state during mixing and molding. The long-term verification mechanism of the 28-day activity index ensures that the microspheres continuously release active ingredients during the curing stage, deeply participating in the secondary hydration reaction and compensating for the lag in strength development in the lightweight aggregate system. Limiting the water requirement ratio reduces the introduction of additional mixing water, inhibits the coarsening and interconnection of the pore structure, thereby improving the material's density and thermal resistance, ultimately achieving simultaneous optimization of thermal insulation and mechanical properties. This solution, combined with the overall design of lightweight, high-strength concrete insulation wall panels for high-rise buildings, further enhances the comprehensive performance of the wall panels under extreme loads and environments.

[0026] This application further proposes that the cenospheres are thin-walled hollow glass microspheres extracted from fly ash, with a fineness of 40~100 mesh and a fineness of 20~40 mesh in a mass ratio of 1:(2~5), and a true density of 0.60~0.70 g / cm³.

[0027] Specifically, cenospheres refer to thin-walled, hollow glass microspheres extracted from fly ash. They can be obtained through the resource utilization of industrial waste. This material naturally possesses a closed-pore structure with low thermal conductivity, thus providing a foundation for its thermal insulation performance. The fineness ratio is designed based on in-depth consideration of particle size distribution. Coarser particles (40-100 mesh) act as a skeleton, providing key support points to enhance overall compressive strength, while finer particles (20-40 mesh) fill the gaps between coarser particles, reducing heat convection paths and increasing slurry density. This ratio ensures that fine particles dominate but are not excessive, avoiding decreased slurry fluidity or loss of lightweight properties due to overfilling. The true density is limited to the range of 0.60-0.70 g / cm³. Based on precise control of the physical properties of the cenospheres, a sufficiently low bulk density is maintained to reduce the self-weight of the wall panel and optimize the thermal insulation effect, while preventing the risk of particle breakage caused by excessively low density.

[0028] In detail, the above solution systematically resolves the contradiction between lightweighting and structural strength in wall panels by precisely defining the source, fineness ratio, and true density of the cenospheres. The thin-walled hollow structure of the cenospheres not only enables the resource utilization of industrial waste but also enhances thermal insulation performance through their naturally formed low thermal conductivity closed pores. The mass ratio of 40-100 mesh particles to 20-40 mesh particles is controlled at 1:(2-5). This ratio effectively enhances overall compressive strength while reducing heat convection paths and increasing slurry density. The defined true density range ensures that the cenospheres synergistically strengthen the mechanical stability and thermal insulation continuity of the wall panel at the microscopic level. Furthermore, when cenospheres work in conjunction with other raw materials such as cement, slag powder, and silica fume, they can further optimize the uniformity of the internal structure of the wall panel, thereby significantly improving its overall performance.

[0029] Through the above technical solutions, the internal structure of the wall panel is more uniform, the strength is enhanced, and the thermal insulation performance is more stable, which meets the comprehensive requirements of high-rise buildings for lightweight, high strength, and reliable thermal insulation under extreme environments and complex loads.

[0030] This application further proposes that the alkali-resistant glass fiber has a density ≤2.7g / cm³, a softening point ≥850℃, and a melting temperature ≥1500℃.

[0031] Alkali-resistant glass fiber refers to a specially treated glass fiber material that maintains stability in alkaline environments. The density limit of no more than 2.7 g / cm³ is primarily achieved by optimizing the fiber's chemical composition and manufacturing process. For example, using a low-density silicate system as the base raw material and adjusting the fiber density by controlling process parameters such as drawing speed and cooling rate. This limitation aims to maintain the fiber's lightweight characteristics to meet the overall lightweight requirements of wall panels while avoiding the increased weight due to excessive density. The softening point of no less than 850℃ can be achieved by introducing appropriate amounts of high-temperature resistant components such as alumina and zirconium oxide into the glass composition. These components effectively improve the fiber's thermal stability. The melting temperature requirement of no less than 1500℃ can be achieved by optimizing the fiber's crystal structure and chemical bonding methods, for example, by using mineral raw materials with higher melting points or by altering the fiber's microstructure through special heat treatment processes.

[0032] Specifically, the aforementioned technical solution systematically addresses the performance stability issue of high-rise building wall panels in extreme environments by precisely controlling the key physical property parameters of alkali-resistant glass fibers. Reasonable density control ensures that the fibers maintain strength without significantly increasing the wall panel's weight, aligning with the overall lightweight design goal. The increased softening point ensures the fibers remain morphologically stable during the rapid temperature rise in the initial stages of a fire, providing a crucial window for evacuation. The increased melting temperature prevents the fibers from melting and leaking under direct exposure to extreme high-temperature flames, continuously providing skeletal support and blocking heat conduction into the wall panel. These characteristics, combined with other components in the wall panel, significantly improve its fire resistance and high-temperature stability while maintaining its mechanical properties, meeting the core requirement of high-rise buildings for material durability in sustained high-temperature environments.

[0033] The above technical solution not only solves the problem of fiber softening or melting under high temperature conditions, but also achieves a dual improvement in the structural reliability and fire barrier function of the wall panel under extreme conditions. This design is particularly suitable for fire or high-temperature conditions that high-rise buildings may encounter, effectively preventing the loss of structural integrity of the wall panel, blocking the spread of fire, and meeting the stringent requirements of building fire safety codes for the high-temperature stability of materials.

[0034] This application further proposes that the water-reducing agent is a polycarboxylate water-reducing agent with a water reduction rate of 25-40% and a solid content of 30-40%.

[0035] Specifically, polycarboxylate superplasticizer refers to a high-efficiency water-reducing agent with a comb-like molecular structure, which can be achieved by copolymerizing polyether monomers with different degrees of polymerization and side chain lengths with unsaturated carboxylic acids. In practical applications, the water reduction rate refers to the percentage reduction in water consumption of concrete while maintaining the same fluidity, which can be achieved by adjusting the dosage and molecular structure design of the polycarboxylate superplasticizer. The solid content refers to the mass percentage of the effective components in the water-reducing agent, which can be achieved by controlling the amount of water evaporation during the reaction process or adjusting the concentration of the liquid phase system.

[0036] In detail, during the preparation of lightweight, high-strength concrete insulation wall panels for high-rise buildings, selecting polycarboxylate superplasticizers with specific parameter ranges can significantly improve the workability of concrete. By strictly controlling the water reduction rate within the range of 25% to 40%, sufficient dispersion of cement particles is ensured, while avoiding excessively high paste viscosity caused by excessive water reduction, thus achieving a balance between concrete fluidity and strength. Simultaneously, setting the solid content within the range of 30% to 40% not only guarantees the dissolution efficiency of the superplasticizer during mixing but also effectively avoids the problems of reduced dispersion and increased costs caused by excessive local concentration. Furthermore, when this superplasticizer is used in combination with raw materials such as cement, slag powder, and silica fume, it can form a more uniform and dense microstructure, thereby improving the overall performance of the wall panel.

[0037] The above technical solution successfully solved the problem of improper control of concrete water-cement ratio, enabling the wall panel to maintain a low density while having higher compressive strength and better durability, thus meeting the comprehensive performance requirements of high-rise buildings for lightweight and high-strength thermal insulation wall panels.

[0038] This application further proposes modified lightweight aggregate with an apparent density of 1.60~1.70 g / cm³, a particle size of 0~5 mm, and a 24h water absorption rate of ≤3%.

[0039] Specifically, modified lightweight aggregate refers to lightweight aggregate that has undergone specific treatment to optimize its physical properties. This can be achieved by mixing shale ceramsite and active slurry in a certain proportion, followed by modification, strengthening, and curing. Apparent density refers to the mass of material per unit volume. This parameter is achieved by precisely controlling the internal porosity and surface characteristics of the aggregate, aiming to balance the lightweight requirements of the wall panel with the mechanical strength requirements. Particle size refers to the maximum size range of aggregate particles, which can be achieved through screening and grading or particle shaping techniques, aiming to optimize the dispersion and encapsulation effect of the aggregate in the concrete matrix. 24-hour water absorption rate refers to the percentage by mass of water absorbed by the aggregate under standard conditions within 24 hours. This can be achieved through surface densification treatment or the introduction of a hydrophobic coating, aiming to improve the durability and thermal insulation performance of the wall panel.

[0040] In detail, the above technical solution effectively solves the core defect caused by unstable aggregate performance in lightweight high-strength concrete insulation wall panels for high-rise buildings by systematically limiting the key physical properties of modified lightweight aggregates. The apparent density is controlled within the range of 1.60~1.70 g / cm³, allowing the modified lightweight aggregates to provide sufficient structural support while maintaining a low self-weight, avoiding the problem of insufficient strength due to excessively low density or excessive density leading to excessive bulk density. The particle size is limited to 0~5mm, optimizing the aggregate particle size distribution to achieve uniform dispersion and full encapsulation of particles in the concrete matrix, which is conducive to forming a dense and continuous microstructure, thereby reducing internal porosity and weak interfaces. The 24-hour water absorption rate does not exceed 3%, effectively blocking the erosion of insulation performance by environmental moisture through strict control of the water intrusion path, while reducing the risk of freeze-thaw cycles and chemical corrosion. Based on this, the modified lightweight aggregate works together with raw materials such as cement, slag powder, and silica fume to ensure that the wall panels meet the dual constraints of self-weight and load-bearing capacity of high-rise buildings while possessing excellent thermal insulation performance and long-term durability.

[0041] This application further proposes that the modified lightweight aggregate is made by mixing shale ceramsite and active slurry at a mass ratio of 3 to 6:1, followed by modification, strengthening, and curing.

[0042] Specifically, modified lightweight aggregate refers to materials formed by mixing and modifying shale ceramsite with an active slurry in a specific ratio. In practical applications, shale ceramsite serves as the core skeleton material, and its natural lightweight properties provide basic thermal insulation for wall panels. However, its original high water absorption rate easily leads to water penetration problems. The active slurry can be composed of 80-100 parts cement, 15-20 parts silica fume, 10-15 parts cenospheres, 15-20 parts water, and 0.5-2 parts polycarboxylate superplasticizer. Its purpose is to achieve a deep cementitious reaction with the aggregate interface under low dosage conditions through a highly reactive design, ensuring that the slurry fully coats the shale ceramsite without significantly increasing the overall density. The precise control of the mixing mass ratio of 3-6:1 is to maintain the lightweight advantage and block water migration channels, overcoming the contradiction in traditional modification where excessive slurry leads to increased density or insufficient slurry leads to high water absorption. The modification, strengthening, and curing process can promote interfacial chemical bonding through thermal activation, and optimize the curing parameters to rapidly densify the shell and form a stable structure with the core.

[0043] In detail, this solution modifies the aggregate by mixing shale ceramsite with an active slurry in a specific ratio to construct a surface-strengthening layer, effectively balancing the requirements of lightweight and low water absorption. The shale ceramsite has an apparent density of 1.3-1.5 g / cm³, a particle size of 0-3 mm, and a 24-hour water absorption rate of ≤15%. These parameters ensure that while providing lightweight properties, the overall performance is not affected by excessive water absorption. The synergistic effect of the components in the active slurry forms a dense barrier on the aggregate surface, avoiding uneven coverage defects caused by relying solely on physical coating. Through modification, strengthening, and curing processes, thermal activation promotes interfacial chemical bonding, rapidly densifying the shell and forming a stable "shell-core" structure with the core, thereby significantly improving the overall impermeability and structural integrity of the aggregate. This technology solves the key bottlenecks in strength and durability of high-rise building insulation wall panels, providing reliable assurance for the long-term performance of the wall panels under complex loads.

[0044] Through the above technical solutions, modified lightweight aggregates not only achieve a balance between low water absorption and high strength and lightweight characteristics, but also effectively solve the problem that conventional lightweight aggregate modification methods are prone to causing excessive water absorption or insufficient structural strength, thus meeting the thermal insulation performance and durability requirements of high-rise buildings.

[0045] This application further proposes that the apparent density of shale ceramsite is 1.3-1.5 g / cm³, the particle size is 0-3 mm, and the water absorption rate is ≤15% in 24 hours; the active slurry is composed of 80-100 parts cement, 15-20 parts silica fume, 10-15 parts cenospheres, 15-20 parts water, and 0.5-2 parts polycarboxylate superplasticizer.

[0046] Shale ceramsite refers to a lightweight aggregate made primarily from shale through high-temperature sintering. The desired apparent density and water absorption can be achieved by controlling the sintering temperature and time, ensuring that the lightweight aggregate provides necessary structural support while reducing overall density. Particle size can be controlled through screening processes to optimize particle distribution and promote uniform contact with the slurry. Active slurry is a composite material system used to modify the surface of lightweight aggregates. It can be achieved through precise proportioning of its components to form a dense and high-strength modified layer.

[0047] Specifically, this technical solution effectively addresses the problems of excessive water absorption, decreased thermal insulation performance, and insufficient structural strength in lightweight aggregates by strictly controlling key parameters of shale ceramsite. Furthermore, the precise proportioning of each component in the active slurry ensures the modification effect and interfacial bonding strength. Cement provides basic cementitious action, silica fume enhances the micro-filling effect and pozzolanic reaction, cenospheres reduce slurry density and improve thermal insulation, water regulates workability, and polycarboxylate superplasticizer optimizes fluidity. These components work together to form a uniform coating layer on the surface of the shale ceramsite, constructing a stable "shell-core" structure, thereby significantly improving the mechanical properties and durability of the wall panel. The combination of this technical solution with the aforementioned wall panel raw material system comprehensively enhances the overall performance of the modified lightweight aggregate, thus ensuring the lightweight, high-strength, and thermal insulation properties of the wall panel.

[0048] In another embodiment, this application also discloses a method for preparing lightweight high-strength concrete thermal insulation wall panels for high-rise buildings, comprising the following steps: S1. Weigh each raw material according to the weight parts. First, add cement, slag powder, silica fume, microspheres, and cenospheres to the mixer and stir at 100-150 rpm for 3-5 minutes until a uniform dry powder state is reached. Then, dissolve the polycarboxylate superplasticizer in water to form a solution and add it in two parts. The first time, add 70% of the solution and stir at 200 rpm for 2 minutes to form a uniform slurry. The second time, add the remaining 30% of the solution and simultaneously and slowly add alkali-resistant glass fiber, pre-dispersing it into 12-18 mm short chopped fibers. Stir at 250 rpm for 1 minute to avoid fiber clumping. Finally, a fluid slurry with uniformly dispersed fibers is formed, and the spread is controlled at 250-300 mm. S2. Immerse the shale ceramsite into the S1 slurry and stir it with a paddle mixer at 80 rpm for 8 minutes to ensure that the slurry fully coats the surface of the aggregate. Then, sieve it through a 5 mm vibrating screen to remove excess slurry and retain the aggregate with a surface slurry coating thickness of 1-2 mm. This process forms a "shell-core" structure. S3. Place the aggregate soaked and screened in S2 into an accelerated curing chamber for curing. The temperature of the curing chamber is 60-90℃ and the curing time is 6-8 hours to obtain a lightweight high-strength concrete thermal insulation wall panel.

[0049] The core innovation of this embodiment lies in combining an optimized mixing process with a "shell-core" structural design and introducing accelerated curing technology. This solves the problems of uneven fiber dispersion, weak interfacial bonding, and slow strength development in the preparation of lightweight, high-strength concrete insulation wall panels, achieving a synergistic effect of lightweight, high strength, thermal insulation, fire resistance, and durability. Specifically, in S1, dry powder mixing ensures uniform mixing of cement, slag powder, silica fume, microspheres, and cenospheres, laying the foundation for subsequent slurry formation. The water-reducing agent solution is added in two stages, combined with the gradual introduction of alkali-resistant glass fibers, effectively preventing fiber agglomeration and enhancing the crack resistance and overall strength of the wall panel. The spread is controlled at 250-300 mm to ensure moderate slurry fluidity, facilitating subsequent operations. In S2, the slurry coats shale ceramsite, and the surface coating thickness is precisely controlled, forming a good interfacial bond. At the same time, the "shell-core" structure achieves a balance between lightweight and high strength. In S3, accelerated curing is carried out at 60-90℃ for 6-8 hours, which significantly improves early strength, increases production efficiency, and ensures the long-term durability of the wall panels.

[0050] Through the above technical solutions, the embodiments of this application successfully solve the technical problem that it is difficult to take into account the lightweight, high strength, thermal insulation, fire resistance and durability of lightweight high-strength concrete insulated wall panels for high-rise buildings during the preparation process, and meet the comprehensive performance requirements of prefabricated exterior walls for building energy conservation in the new era.

[0051] Example 1 The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings of the present invention comprises the following components in parts by weight: 300-500 parts cement, 60-90 parts slag powder, 60-100 parts silica fume, 60-90 parts microspheres, 100-200 parts cenospheres, 500-900 parts modified lightweight aggregate, 15-20 parts alkali-resistant glass fiber, 25-40 parts water-reducing agent, and 180-220 parts water.

[0052] Comparative Example 2 The difference between this comparative example and Example 1 is that the unmodified shale ceramsite of Comparative Example 1 is used.

[0053] Comparative Example 3 The difference between this comparative example and Example 1 is that the alkali-resistant glass fiber in Comparative Example 1 is replaced with PVA fiber.

[0054] Comparative Example 4 The difference between this comparative example and Example 1 is that the modified slurry ratio in Comparative Example 1 is changed to 80 parts cement, 25 parts silica fume, 5 parts cenospheres and 30 parts water.

[0055] Table 1 Performance test results of concrete thermal insulation wall panels

[0056] As can be seen from the results in Table 1, the compressive strength can reach 110-120 MPa when the bulk density is 1700-1800 kg / m3 using the present invention; By comparing Example 1 and Comparative Example 2, it can be found that Comparative Example 2 uses unmodified shale ceramsite. The strength of unmodified shale ceramsite is not high, which reduces the mechanical properties of the prepared concrete. At the same time, the water absorption rate increases to 12.1%, affecting the use of the wall. By comparing Example 1 and Comparative Example 3, it can be found that although the mechanical strength of the prepared concrete is slightly reduced, the PVA fiber has a low melting point and low fire resistance. Examples 1 and 4 show that improperly formulated modified slurry not only increases the density of modified shale ceramsite and results in high-density thermal insulation concrete, but also reduces the mechanical properties of the concrete.

[0057] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0058] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0059] Additionally, "multiple" refers to two or more.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings, characterized in that, The raw materials include the following parts by weight: 300-500 parts cement, 60-90 parts slag powder, 60-100 parts silica fume, 60-90 parts microspheres, 100-200 parts cenospheres, 500-900 parts modified lightweight aggregate, 15-20 parts alkali-resistant glass fiber, 25-40 parts water-reducing agent, and 180-220 parts water.

2. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 1, characterized in that: The cement is P. I or P One of the types of O 52.5 cement; The slag powder is S105 slag powder; The silica fume has a specific surface area ≥23000m² / kg, SiO2 content ≥95%, 28d activity index ≥95%, and water requirement ratio ≤110%.

3. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 1, characterized in that: The microspheres are fly ash microspheres with a specific surface area ≥1200m² / kg, a median diameter of 1.8~2.3μm, a 28d activity index ≥75%, and a water requirement ratio ≤95%.

4. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 1, characterized in that: The microspheres are thin-walled hollow glass microspheres extracted from fly ash, with a mass ratio of 40-100 mesh and 20-40 mesh of 1:(2-5), and a true density of 0.60-0.70 g / cm³.

5. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 1, characterized in that: The alkali-resistant glass fiber has a density ≤2.7g / cm³, a softening point ≥850℃, and a melting temperature ≥1500℃.

6. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 1, characterized in that: The water-reducing agent is a polycarboxylate water-reducing agent with a water reduction rate of 25-40% and a solid content of 30-40%.

7. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 1, characterized in that: The modified lightweight aggregate has an apparent density of 1.60~1.70 g / cm³, a particle size of 0~5 mm, and a 24h water absorption rate of ≤3%.

8. The lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 7, characterized in that: The modified lightweight aggregate is made by mixing shale ceramsite and active slurry at a mass ratio of 3 to 6:1, followed by modification, strengthening, and curing.

9. A lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to claim 8, characterized in that: The apparent density of the shale ceramsite is 1.3-1.5 g / cm³, the particle size is 0-3 mm, and the water absorption rate is ≤15% after 24 hours. The active slurry is composed of 80-100 parts cement, 15-20 parts silica fume, 10-15 parts cenospheres, 15-20 parts water, and 0.5-2 parts polycarboxylate superplasticizer.

10. A method for preparing a lightweight, high-strength concrete thermal insulation wall panel for high-rise buildings according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Weigh each raw material according to the weight parts. First, add cement, slag powder, silica fume, microspheres, and cenospheres to the mixer and stir at 100-150 rpm for 3-5 minutes until a uniform dry powder state is reached. Then, dissolve the polycarboxylate superplasticizer in water to form a solution and add it in two parts. The first time, add 70% of the solution and stir at 200 rpm for 2 minutes to form a uniform slurry. The second time, add the remaining 30% of the solution and simultaneously add alkali-resistant glass fiber slowly at 250 rpm for 1 minute to avoid fiber clumping. Finally, a fluid slurry with uniformly dispersed fibers is formed. S2. Immerse the shale ceramsite into the S1 slurry and stir it with a paddle mixer at 80 rpm for 8 minutes to ensure that the slurry fully coats the surface of the aggregate. Then, sieve it through a 5 mm vibrating screen to remove excess slurry and retain the aggregate with a surface slurry coating thickness of 1-2 mm. This process forms a "shell-core" structure. S3. Place the aggregate soaked and screened in S2 into an accelerated curing chamber for curing. The temperature of the curing chamber is 60-90℃ and the curing time is 6-8 hours to obtain the lightweight high-strength concrete insulation wall panel.

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