A high-strength, high-weather-resistant inorganic artificial stone and its preparation method

Abstract

This invention discloses a high-strength, high-weather-resistant inorganic artificial stone and its preparation method, belonging to the field of building materials technology. This invention achieves excellent density and bonding strength by adding low-alkali silicate cement, metakaolin, and silica fume for synergistic hydration. The addition of modified coarse aggregate and composite fine aggregate, along with gradation optimization, promotes packing density and reduces shrinkage cracking. Reinforcing agent A provides toughening and crack resistance, while reinforcing agent B exhibits a nano-filling effect. A composite accelerator helps improve the strength of the inorganic artificial stone, reducing the risk of cracking and deformation, and shortening the curing period. Furthermore, the weather-resistant PVA fiber in reinforcing agent A has excellent weather resistance, and the synergistic effect of nano-titanium dioxide and nano-zinc oxide in reinforcing agent B also helps delay material aging. The modified coarse aggregate possesses interfacial hydrophobicity. The interaction of the components in the formula results in an inorganic artificial stone with high flexural strength, high compressive strength, and excellent crack resistance.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and more specifically, to a high-strength, high-weather-resistant inorganic artificial stone and its preparation method. Background Technology

[0002] Inorganic artificial stone is a type of building decoration material made from inorganic cementitious materials such as cement, combined with quartz sand, aggregates, etc., through processes such as mixing, molding, curing, and processing. It is widely used for countertops, wall and floor tiles, decorative panels, and irregularly shaped components. Compared with organic artificial stone (resin-based artificial stone), inorganic artificial stone has outstanding advantages such as being environmentally friendly, fireproof, aging-resistant, and non-radioactive, making it an important development direction for replacing natural stone and organic artificial stone.

[0003] Currently, inorganic artificial stone mainly uses silicate cement as the cementing material, and its curing process is generally moist heat curing, that is, curing in a large curing box at 40~70℃ and humidity ≥95% for 24~48 hours. However, this process has the following significant drawbacks: 1. High energy consumption and high carbon emissions. High-temperature moist heat curing requires continuous heating and humidification, resulting in large equipment investment and high operating energy consumption, which does not conform to the green and low-carbon development direction. 2. Long curing cycle and low production efficiency. The 24~48h curing cycle severely restricts production efficiency and capacity, while normal temperature curing requires 7~28 days to reach usable strength. 3. Prone to cracking and deformation. Cement has a large heat of hydration and a high shrinkage rate, which makes the slabs prone to warping and cracking during curing and later use, affecting the product qualification rate and service life. 4. Severe efflorescence and whitening. In traditional silicate cement systems and alkali-activated systems, soluble alkali migrates to the surface with moisture and reacts with CO2 in the air to form carbonates, causing the surface of the slab to turn white, severely affecting its appearance and durability. 5. High water absorption and poor stain resistance. Traditional inorganic artificial stone has high porosity, allowing pollutants to easily penetrate, resulting in insufficient stain resistance.

[0004] To address the aforementioned issues, existing technologies have yielded relevant research. For example, Chinese Patent Publication No. CN112851208B discloses a solid waste-based inorganic artificial stone and its preparation method, employing a moist heat curing process with a curing temperature of 35-45℃ and a humidity of 65-85%, but the curing time remains relatively long. Another example is Chinese Patent Publication No. CN112094084A, which discloses an inorganic artificial stone and its preparation method, obtaining the product by curing in a curing chamber at a temperature of 40-70℃ and a humidity ≥95% for 24-48 hours; however, the curing temperature is too high and the curing cycle is long. None of these existing technologies simultaneously solve the problems of high energy consumption, long curing cycles, and insufficient product performance. For example, Chinese Patent Publication No. CN115650657A discloses a high-toughness inorganic artificial stone reinforced with multiple materials and its manufacturing method. It uses white cement in combination with raw materials such as metakaolin, silica fume, nanomaterials and fibers. Although it improves the toughness and crack resistance of the board to a certain extent, the amount of white cement used is as high as 31.5%~33.5%, and it still relies on conventional curing processes. It fails to solve the problems of curing energy consumption and cycle, and does not propose a systematic solution to the problem of efflorescence and whitening.

[0005] Therefore, providing an inorganic artificial stone that simultaneously possesses high strength, low shrinkage, no efflorescence, and high weather resistance, as well as its preparation method, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] Based on this, in order to solve one of the above-mentioned technical problems, the present invention provides a high-strength, high-weather-resistant inorganic artificial stone and its preparation method, the specific technical solution of which is as follows: A high-strength, high-weather-resistant inorganic artificial stone, comprising the following raw materials in parts by weight: 25-35 parts low-alkali silicate cement, 8-12 parts metakaolin, 5-8 parts silica fume, 25-30 parts modified coarse aggregate, 10-25 parts composite fine aggregate, 1-3 parts reinforcing agent A, 3-7 parts reinforcing agent B, 2-4 parts water-reducing agent, 2-5 parts composite accelerator and early-strength agent, 0.5-3 parts colorant, and 18-25 parts water; The modified coarse aggregate is hydrophobic modified quartz sand; the reinforcing agent A is obtained by mixing weather-resistant PVA fiber with modified glass flakes; and the reinforcing agent B is a weather-resistant reinforcing agent.

[0007] Furthermore, the preparation method of the hydrophobically modified quartz sand is as follows: Quartz sand is added to treatment solution A and stirred at 50~100 r / min and 90~120℃ for 20~30 min. After filtration, washing and drying, hydrophobic modified quartz sand is obtained.

[0008] Further, the treatment solution A is an aqueous ethanol solution containing 1-3% by mass of γ-methacryloxypropyltrimethoxysilane, and the volume ratio of ethanol to water in the aqueous ethanol solution is (1-3):(7-9).

[0009] Furthermore, the preparation method of the weather-resistant PVA fiber is as follows: an antioxidant and an ultraviolet absorber are added to the PVA spinning solution, and the solution is stirred at a speed of 100~300r / min for 30~60min. After standing to remove bubbles, the solution is spun, stretched and post-treated to obtain the weather-resistant PVA fiber.

[0010] Furthermore, the amount of antioxidant added accounts for 0.1-1% of the mass of the PVA spinning solution; the amount of ultraviolet absorber added accounts for 0.1-2% of the mass of the PVA spinning solution.

[0011] Furthermore, the modified glass flakes are prepared by adding glass flakes to treatment solution B, soaking for 30-60 minutes, filtering and drying to obtain modified glass flakes.

[0012] Furthermore, the treatment solution B is an aqueous ethanol solution containing 1-2% by mass of vinyl(β-methoxyethoxy)silane, and the volume ratio of ethanol to water in the aqueous ethanol solution is (1-3):(7-9).

[0013] Furthermore, the composite fine aggregate is obtained by mixing marble powder and calcium carbonate in a mass ratio of (10~15):(4~5).

[0014] Furthermore, the composite coagulation and early strength accelerator is obtained by mixing anhydrous gypsum and trisodium citrate in a mass ratio of (8~9):(1~2).

[0015] In addition, the present invention also provides a method for preparing high-strength and high-weather-resistant inorganic artificial stone, the preparation method comprising the following steps: S1. Add low-alkali silicate cement, metakaolin, silica fume, modified coarse aggregate, composite fine aggregate, reinforcing agent A, reinforcing agent B, colorant and composite accelerator to a mixer and mix at a mixing speed of 10~30r / min for 3~5min to obtain a mixture; S2. Add water and water-reducing agent to the mixture, and continue stirring for 5-10 minutes to obtain a slurry; S3. The slurry is laid in the mold and vibrated for 1 to 3 minutes at a vibration frequency of 40 to 60 Hz. After pressure treatment, it is cured for 4 to 8 hours at a temperature of 30 to 50 ℃ and a relative humidity of ≥90%. The mold is then demolded to obtain the blank. S4. After demolding, the blank obtained is cured at room temperature for 3-7 days, and then scraped, sized, and polished to obtain high-strength and high-weather-resistant inorganic artificial stone.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention optimizes the formulation of inorganic artificial stone to obtain inorganic artificial stone with high flexural strength, high compressive strength, and excellent crack resistance. Specifically, through the synergistic hydration of a multi-component cementitious system of low-alkali silicate cement, metakaolin, and silica fume, silica fume microspheres fill the pores, and metakaolin undergoes a pozzolanic reaction to refine the pore structure, significantly improving the matrix density and bonding strength; through the gradation optimization of modified coarse aggregate (hydrophobic modified quartz sand) and composite fine aggregate (marble powder and calcium carbonate compound), the packing density is improved, reducing shrinkage cracking and resulting in better dimensional stability; the addition of reinforcing agent A (modified glass flakes and weather-resistant PVA fiber) has a toughening and crack-resistant effect, and the addition of reinforcing agent B (nano titanium dioxide and nano zinc oxide) has a nano-filling effect; the addition of a composite accelerator helps to improve the strength of inorganic artificial stone, reduce the risk of cracking and deformation of the green body, and shorten the curing cycle.

[0017] 2. The weather-resistant PVA fiber in the reinforcing agent A of the present invention is modified by adding antioxidants and ultraviolet absorbers to give the weather-resistant PVA fiber weather resistance. The nano titanium dioxide and nano zinc oxide in the reinforcing agent B also help to delay the aging of the material. The modified coarse aggregate is hydrophobically modified by silane coupling agent to improve the hydrophobic properties of the interface. The interaction of the components in the formula can significantly increase the aging resistance and long-term stability of inorganic artificial stone.

[0018] 3. This invention uses low-alkali silicate cement as a cementitious material, reducing the content of soluble alkali from the source; the pozzolanic activity of metakaolin and silica fume can consume the calcium hydroxide produced by cement hydration, reducing the migration of free alkali; the composite accelerator promotes early hydration and accelerates structural densification; the hydrophobic properties of modified coarse aggregate reduce moisture migration channels. The synergistic effect of these multiple mechanisms effectively solves the industry problem of efflorescence and whitening on the surface of traditional inorganic artificial stone. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] An embodiment of the present invention provides a high-strength, high-weather-resistant inorganic artificial stone, comprising the following raw materials in parts by weight: 25-35 parts of low-alkali silicate cement, 8-12 parts of metakaolin, 5-8 parts of silica fume, 25-30 parts of modified coarse aggregate, 10-25 parts of composite fine aggregate, 1-3 parts of reinforcing agent A, 3-7 parts of reinforcing agent B, 2-4 parts of water-reducing agent, 2-5 parts of composite accelerator and early-strength agent, 0.5-3 parts of colorant, and 18-25 parts of water; The modified coarse aggregate is hydrophobic modified quartz sand; the reinforcing agent A is obtained by mixing weather-resistant PVA fiber with modified glass flakes; and the reinforcing agent B is a weather-resistant reinforcing agent.

[0022] In one embodiment, the low-alkali silicate cement is grade 52.5 silicate cement with an alkali content of ≤0.6%. The cement of this invention has an alkali content of ≤0.6%, which effectively suppresses efflorescence, frost, and whitening problems. It exhibits stable appearance and no weathering or deterioration during long-term outdoor use, significantly extending its weather resistance lifespan.

[0023] In one embodiment, the metakaolin has a fineness of ≥800 mesh.

[0024] In one embodiment, the silica ash has a SiO2 content of ≥90%.

[0025] In one embodiment, the method for preparing the hydrophobically modified quartz sand is as follows: Quartz sand is added to treatment solution A and stirred at 50-100 r / min and 90-120℃ for 20-30 min. After filtration, washing, and drying, hydrophobic modified quartz sand is obtained. The hydrophobic modified quartz sand of this invention can reduce the water absorption rate of aggregates, helping to reduce the intrusion of rainwater, moisture, and harmful ions, thereby providing inorganic artificial stone with resistance to weathering and water seepage.

[0026] In one embodiment, the treatment solution A is an aqueous ethanol solution containing 1-3% by mass of γ-methacryloxypropyltrimethoxysilane, and the volume ratio of ethanol to water in the aqueous ethanol solution is (1-3):(7-9).

[0027] In one embodiment, the weight ratio of the quartz sand to the treatment liquid A is (25~30):(50~100).

[0028] In one embodiment, the quartz sand has a particle size of 20-120 mesh.

[0029] In one embodiment, the quartz sand is graded as follows: 20-40 mesh, 40-80 mesh, and 80-120 mesh, with a mass ratio of (4-7):(1-3):(1-5). This invention uses three-stage graded quartz sand, which helps to improve packing density, reduce internal voids, and further enhance strength and impermeability.

[0030] In one embodiment, the weather-resistant PVA fiber is prepared by adding an antioxidant and a UV absorber to a PVA spinning solution, stirring at 100-300 r / min for 30-60 min, allowing it to stand and degas, and then spinning, stretching, and post-treatment to obtain the weather-resistant PVA fiber. This invention protects the fiber from UV and oxidative aging, preventing fiber embrittlement and failure. Furthermore, the addition of weather-resistant PVA fiber creates a three-dimensional random distribution, which can bridge microcracks under stress and prevent crack propagation. It should be noted that the spinning process is a conventional technique and will not be described in detail here.

[0031] In one embodiment, the amount of antioxidant added is 0.1-1% of the mass of the PVA spinning solution; the amount of ultraviolet absorber added is 0.1-2% of the mass of the PVA spinning solution.

[0032] In one embodiment, the antioxidant is at least one of triphenyl phosphate and phenothiazine.

[0033] In one embodiment, the ultraviolet absorber is at least one of 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-octylbenzophenone.

[0034] In one embodiment, the length of the weather-resistant PVA fiber is 6-15 mm.

[0035] In one embodiment, the modified glass flakes are prepared by adding glass flakes to treatment solution B, soaking for 30-60 minutes, filtering, and drying to obtain modified glass flakes. In this invention, the modified glass flakes not only have better interfacial bonding performance with the cement matrix but also form a labyrinth effect, which helps improve the strength and weather resistance of inorganic artificial stone. The flaky modified glass flakes, in synergy with weather-resistant PVA fibers, further improve the crack resistance of inorganic artificial stone.

[0036] In one embodiment, the treatment solution B is an aqueous ethanol solution containing 1-2% by mass of vinyl(β-methoxyethoxy)silane, and the volume ratio of ethanol to water in the aqueous ethanol solution is (1-3):(7-9).

[0037] In one embodiment, the weight ratio of the glass flakes to the treatment liquid B is (1~5):(20~50).

[0038] In one embodiment, the aspect ratio of the glass flakes is 50 to 150.

[0039] In one embodiment, the mass ratio of the weather-resistant PVA fiber to the modified glass flakes is (4~8):(1~3).

[0040] In one embodiment, the weather-resistant reinforcing agent is obtained by mixing nano-titanium dioxide and nano-zinc oxide in a mass ratio of (1~3):(1~5). The nano-titanium dioxide and nano-zinc oxide of this invention can form a certain degree of ultraviolet shielding, which helps reduce the damage of ultraviolet rays to inorganic artificial stone, thereby improving weather resistance. Furthermore, the nano-scale weather-resistant reinforcing agent can fill micron-scale pores, refine hydrated crystals, and improve matrix density and compressive strength; it also possesses a certain photocatalytic self-cleaning effect, reducing the adhesion of dirt to outdoor stone surfaces.

[0041] In one embodiment, the nano-titanium dioxide has a particle size of 20-50 nm.

[0042] In one embodiment, the nano-zinc oxide has a particle size of 20-50 nm.

[0043] In one embodiment, the composite fine aggregate is obtained by mixing marble powder and calcium carbonate in a mass ratio of (10~15):(4~5). In the composite fine aggregate of the present invention, marble powder can fill voids, improve the workability of the slurry, enhance the surface texture and gloss after polishing, fine-tune the coefficient of thermal expansion of the system, and reduce shrinkage; calcium carbonate can fill smaller voids, help improve the density of the blank, and improve the performance of subsequent polishing processing.

[0044] In one embodiment, the marble powder has a fineness of 300-325 mesh.

[0045] In one embodiment, the calcium carbonate has a fineness of 1000-1300 mesh.

[0046] In one embodiment, the water-reducing agent is a polycarboxylate-based high-efficiency water-reducing agent. The polycarboxylate-based high-efficiency water-reducing agent of the present invention can efficiently disperse cement and active powder particles, break up agglomerates, significantly reduce the water demand of the system, ensure the fluidity of the slurry, and reduce drying shrinkage and cracking.

[0047] In one embodiment, the composite accelerator is obtained by mixing anhydrous gypsum and trisodium citrate in a mass ratio of (8~9):(1~2). The anhydrous gypsum in the composite accelerator can rapidly react with the cement-alumina phase to form ettringite, significantly increasing the early hydration rate, achieving early strength in a short time, shortening the wet heat curing time, facilitating rapid demolding, and reducing green body deformation and collapse. The trisodium citrate acts as a retarding and regulating component, balancing the problems of rapid slurry setting and poor operability caused by the excessively rapid setting of anhydrous gypsum, helping to ensure sufficient time for slurry spreading and vibration molding, thus ensuring production quality while maintaining production efficiency.

[0048] In addition, the present invention also provides a method for preparing high-strength and high-weather-resistant inorganic artificial stone, the preparation method comprising the following steps: S1. Add low-alkali silicate cement, metakaolin, silica fume, modified coarse aggregate, composite fine aggregate, reinforcing agent A, reinforcing agent B, colorant and composite accelerator to a mixer and mix at a mixing speed of 10~30r / min for 3~5min to obtain a mixture; S2. Add water and water-reducing agent to the mixture, and continue stirring for 5-10 minutes to obtain a slurry; S3. The slurry is laid in the mold and vibrated for 1 to 3 minutes at a vibration frequency of 40 to 60 Hz. After pressure treatment, it is cured for 4 to 8 hours at a temperature of 30 to 50 ℃ and a relative humidity of ≥90%. The mold is then demolded to obtain the blank. S4. After demolding, the blank obtained is cured at room temperature for 3-7 days, and then scraped, sized, and polished to obtain high-strength and high-weather-resistant inorganic artificial stone.

[0049] In one embodiment, in step S3, the pressure of the pressurization process is 5~15MPa, and the time is 1~5min.

[0050] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.

[0051] Example 1: The raw materials for preparing a high-strength, high-weather-resistant inorganic artificial stone in this embodiment are as follows: 28 parts low-alkali silicate cement, 10 parts metakaolin, 6 parts silica fume, 27 parts hydrophobic modified quartz sand, 15 parts composite fine aggregate, 2 parts reinforcing agent A, 5 parts reinforcing agent B, 2 parts polycarboxylate-based high-efficiency water-reducing agent, 3 parts composite accelerator and early strength agent, 1.5 parts colorant, and 21 parts water. The low-alkali silicate cement is grade 52.5 silicate cement with an alkali content ≤0.6%; the metakaolin has a fineness of 1000 mesh; the silica fume has an SiO2 content ≥90%; the composite fine aggregate is obtained by mixing marble powder and calcium carbonate in a mass ratio of 10:5, with the marble powder having a fineness of 325 mesh and the calcium carbonate having a fineness of 1250 mesh; the reinforcing agent A is obtained by mixing weather-resistant PVA fiber and modified glass flakes in a mass ratio of 7:3; the reinforcing agent B is obtained by mixing nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1, with both nano-titanium dioxide and nano-zinc oxide having a particle size of 50 nm; the composite accelerator and early-strength agent is obtained by mixing anhydrous gypsum and trisodium citrate in a mass ratio of 9:1. The preparation method of the hydrophobic modified quartz sand is as follows: 30 parts by weight of quartz sand (graded as follows: 20~40 mesh quartz sand, 40~80 mesh quartz sand and 80~120 mesh quartz sand in a mass ratio of 4:3:3) are added to 50 parts of treatment solution A (containing 2% by mass of γ-methacryloyloxypropyltrimethoxysilane in an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:7). The mixture is stirred at 105℃ for 30 minutes at a speed of 50 r / min. After filtration, washing and drying, hydrophobic modified quartz sand is obtained. The preparation method of the weather-resistant PVA fiber is as follows: 0.5% of triphenyl phosphate and 0.3% of 2-hydroxy-4-methoxybenzophenone by mass of the PVA spinning solution are added to the PVA spinning solution. The solution is stirred at 100 r / min for 40 min. After standing to remove bubbles, the solution is spun, stretched and post-treated to obtain weather-resistant PVA fiber with a length of 12 mm. The modified glass flakes are prepared by adding 5 parts by weight of glass flakes with a diameter-to-thickness ratio of 60 to 20 parts by weight of treatment solution B (containing 1% by weight of vinyl(β-methoxyethoxy)silane in an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:7), soaking for 30 minutes, and then filtering and drying to obtain modified glass flakes. This embodiment describes a method for preparing high-strength, high-weather-resistant inorganic artificial stone, comprising the following steps: S1. Add low-alkali silicate cement, metakaolin, silica fume, modified coarse aggregate, composite fine aggregate, reinforcing agent A, reinforcing agent B, colorant and composite accelerator to a mixer and stir at a stirring speed of 20 r / min for 5 min to obtain a mixture; S2. Add water and water-reducing agent to the mixture, and continue stirring for 10 minutes to obtain a slurry; S3. The slurry is laid in the mold, vibrated at a vibration frequency of 50Hz for 2 minutes, pressurized at a pressure of 10MPa for 1 minute, and then cured at a temperature of 45℃ and a relative humidity of 92% for 5 hours. The mold is then removed to obtain the blank. S4. After demolding, the blank obtained is cured at room temperature for 5 days, and then scraped, sized, and polished to obtain high-strength and high-weather-resistant inorganic artificial stone.

[0052] Example 2: The raw materials for preparing a high-strength, high-weather-resistant inorganic artificial stone in this embodiment are as follows: 30 parts low-alkali silicate cement, 11 parts metakaolin, 7 parts silica fume, 28 parts hydrophobic modified quartz sand, 15 parts composite fine aggregate, 3 parts reinforcing agent A, 4 parts reinforcing agent B, 3 parts polycarboxylate-based high-efficiency water-reducing agent, 4 parts composite accelerator and early strength agent, 1.5 parts colorant, and 23 parts water. The low-alkali silicate cement is grade 52.5 silicate cement with an alkali content ≤0.6%; the metakaolin has a fineness of 1000 mesh; the silica fume has an SiO2 content ≥90%; the composite fine aggregate is obtained by mixing marble powder and calcium carbonate in a mass ratio of 10:5, with the marble powder having a fineness of 325 mesh and the calcium carbonate having a fineness of 1250 mesh; the reinforcing agent A is obtained by mixing weather-resistant PVA fiber and modified glass flakes in a mass ratio of 7:3; the reinforcing agent B is obtained by mixing nano-titanium dioxide and nano-zinc oxide in a mass ratio of 2:3, with both nano-titanium dioxide and nano-zinc oxide having a particle size of 50 nm; the composite accelerator and early-strength agent is obtained by mixing anhydrous gypsum and trisodium citrate in a mass ratio of 9:1. The preparation method of the hydrophobic modified quartz sand is as follows: 30 parts by weight of quartz sand (graded as follows: 20~40 mesh quartz sand, 40~80 mesh quartz sand and 80~120 mesh quartz sand in a mass ratio of 4:3:3) are added to 50 parts of treatment solution A (containing 2% by mass of γ-methacryloyloxypropyltrimethoxysilane in an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:7). The mixture is stirred at 105℃ for 30 minutes at a speed of 50 r / min. After filtration, washing and drying, hydrophobic modified quartz sand is obtained. The preparation method of the weather-resistant PVA fiber is as follows: 0.5% of triphenyl phosphate and 0.3% of 2-hydroxy-4-methoxybenzophenone by mass of the PVA spinning solution are added to the PVA spinning solution. The solution is stirred at 100 r / min for 40 min. After standing to remove bubbles, the solution is spun, stretched and post-treated to obtain weather-resistant PVA fiber with a length of 12 mm. The modified glass flakes are prepared by adding 5 parts by weight of glass flakes with a diameter-to-thickness ratio of 60 to 20 parts by weight of treatment solution B (containing 1% by weight of vinyl(β-methoxyethoxy)silane in an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:7), soaking for 30 minutes, and then filtering and drying to obtain modified glass flakes. This embodiment describes a method for preparing high-strength, high-weather-resistant inorganic artificial stone, comprising the following steps: S1. Add low-alkali silicate cement, metakaolin, silica fume, modified coarse aggregate, composite fine aggregate, reinforcing agent A, reinforcing agent B, colorant and composite accelerator to a mixer and stir at a stirring speed of 20 r / min for 5 min to obtain a mixture; S2. Add water and water-reducing agent to the mixture, and continue stirring for 10 minutes to obtain a slurry; S3. The slurry is laid in the mold, vibrated at a vibration frequency of 50Hz for 2 minutes, pressurized at a pressure of 10MPa for 1 minute, and then cured at a temperature of 45℃ and a relative humidity of 92% for 5 hours. The mold is then removed to obtain the blank. S4. After demolding, the blank obtained is cured at room temperature for 5 days, and then scraped, sized, and polished to obtain high-strength and high-weather-resistant inorganic artificial stone.

[0053] Example 3: The raw materials for preparing a high-strength, high-weather-resistant inorganic artificial stone in this embodiment are as follows: 32 parts low-alkali silicate cement, 12 parts metakaolin, 8 parts silica fume, 30 parts hydrophobic modified quartz sand, 15 parts composite fine aggregate, 3 parts reinforcing agent A, 4 parts reinforcing agent B, 4 parts polycarboxylate-based high-efficiency water-reducing agent, 5 parts composite accelerator and early strength agent, 1.5 parts colorant, and 25 parts water. The low-alkali silicate cement is grade 52.5 silicate cement with an alkali content ≤0.6%; the metakaolin has a fineness of 1000 mesh; the silica fume has an SiO2 content ≥90%; the composite fine aggregate is obtained by mixing marble powder and calcium carbonate in a mass ratio of 10:5, with the marble powder having a fineness of 325 mesh and the calcium carbonate having a fineness of 1250 mesh; the reinforcing agent A is obtained by mixing weather-resistant PVA fiber and modified glass flakes in a mass ratio of 7:3; the reinforcing agent B is obtained by mixing nano-titanium dioxide and nano-zinc oxide in a mass ratio of 3:2, with both nano-titanium dioxide and nano-zinc oxide having a particle size of 50 nm; the composite accelerator and early-strength agent is obtained by mixing anhydrous gypsum and trisodium citrate in a mass ratio of 9:1. The preparation method of the hydrophobic modified quartz sand is as follows: 30 parts by weight of quartz sand (graded as follows: 20~40 mesh quartz sand, 40~80 mesh quartz sand and 80~120 mesh quartz sand in a mass ratio of 4:3:3) are added to 50 parts of treatment solution A (containing 2% by mass of γ-methacryloyloxypropyltrimethoxysilane in an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:7). The mixture is stirred at 105℃ for 30 minutes at a speed of 50 r / min. After filtration, washing and drying, hydrophobic modified quartz sand is obtained. The preparation method of the weather-resistant PVA fiber is as follows: 0.5% of triphenyl phosphate and 0.3% of 2-hydroxy-4-methoxybenzophenone by mass of the PVA spinning solution are added to the PVA spinning solution. The solution is stirred at 100 r / min for 40 min. After standing to remove bubbles, the solution is spun, stretched and post-treated to obtain weather-resistant PVA fiber with a length of 12 mm. The modified glass flakes are prepared by adding 5 parts by weight of glass flakes with a diameter-to-thickness ratio of 60 to 20 parts by weight of treatment solution B (containing 1% by weight of vinyl(β-methoxyethoxy)silane in an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:7), soaking for 30 minutes, and then filtering and drying to obtain modified glass flakes. This embodiment describes a method for preparing high-strength, high-weather-resistant inorganic artificial stone, comprising the following steps: S1. Add low-alkali silicate cement, metakaolin, silica fume, modified coarse aggregate, composite fine aggregate, reinforcing agent A, reinforcing agent B, colorant and composite accelerator to a mixer and stir at a stirring speed of 20 r / min for 5 min to obtain a mixture; S2. Add water and water-reducing agent to the mixture, and continue stirring for 10 minutes to obtain a slurry; S3. The slurry is laid in the mold, vibrated at a vibration frequency of 50Hz for 2 minutes, pressurized at a pressure of 10MPa for 1 minute, and then cured at a temperature of 45℃ and a relative humidity of 92% for 6 hours. The mold is then removed to obtain the blank. S4. After demolding, the blank obtained is cured at room temperature for 5 days, and then scraped, sized, and polished to obtain high-strength and high-weather-resistant inorganic artificial stone.

[0054] Comparative Example 1: The difference between Comparative Example 1 and Example 3 is that the quartz sand in Comparative Example 1 was not modified, but otherwise it was the same as Example 3.

[0055] Comparative Example 2: The difference between Comparative Example 2 and Example 3 is that no metakaolin and silica fume were added in Comparative Example 2, but were made up by equal amounts of low-alkali silicate cement. Otherwise, they were the same as in Example 3.

[0056] Comparative Example 3: The difference between Comparative Example 3 and Example 3 is that no weather-resistant PVA fiber was added to the reinforcing agent A in Comparative Example 3, but otherwise it is the same as Example 3.

[0057] Comparative Example 4: The difference between Comparative Example 4 and Example 3 is that no modified glass flakes were added to the reinforcing agent A in Comparative Example 4, but otherwise it is the same as Example 3.

[0058] Comparative Example 5: The difference between Comparative Example 5 and Example 3 is that no reinforcing agent A was added in Comparative Example 5, but otherwise it is the same as Example 3.

[0059] Comparative Example 6: The difference between Comparative Example 6 and Example 3 is that Comparative Example 6 did not add reinforcing agent B, that is, it did not add nano titanium dioxide and nano zinc oxide, but otherwise it was the same as Example 3.

[0060] Comparative Example 7: The difference between Comparative Example 7 and Example 3 is that no composite coagulation and early strength accelerator was added in Comparative Example 7, while the rest is the same as in Example 3.

[0061] The inorganic artificial stone samples prepared in Examples 1-3 and the inorganic artificial stone samples prepared in Comparative Examples 1-7 were subjected to performance tests, and the results are shown in Table 1 below.

[0062] The flexural strength and compressive strength tests were conducted according to GB / T35160.2-2017; the water absorption test was conducted according to GB / T35160.1-2017; the efflorescence test involved placing the samples in an environment with 90% humidity and 40℃ to accelerate efflorescence for 7 days, and visually inspecting the percentage of whitened area on the surface, classifying it as none (0%), slight (<10%), moderate (10%~30%), and severe (>30%). Weather resistance testing included an ultraviolet aging test (UVA-340 lamp, irradiance 0.89W / m²). 2 After 500 hours of exposure to light at 60℃ for 4 hours and condensation at 50℃ for 4 hours, the flexural strength retention rate (%) was tested.

[0063] Table 1: Performance Test Results

[0064] Analysis of the data in Table 1 shows that the present invention optimizes the formulation of inorganic artificial stone, resulting in inorganic artificial stone with high flexural strength, high compressive strength, and excellent crack resistance. Compared with Example 3, the quartz sand in Comparative Example 1 was not modified, leading to a significant increase in water absorption, lower flexural and compressive strength compared to Example 3, and slight efflorescence. This indicates that the hydrophobic modification of the quartz sand not only reduces the water absorption of the aggregate itself but also helps to hinder water migration channels. Simultaneously, the silane coupling agent improves the interfacial bonding between the aggregate and cement, contributing to increased strength, impermeability, and inhibition of efflorescence. In Comparative Example 2, without the addition of metakaolin and silica fume, the flexural and compressive strengths were supplemented by an equal amount of low-alkali silicate cement. This resulted in significantly lower flexural and compressive strength compared to Example 3, increased water absorption, severe efflorescence, and a lower weather resistance strength retention rate. This indicates that the pozzolanic reaction between metakaolin and silica fume not only consumes Ca(OH)2 generated during cement hydration and reduces free alkali migration, but also refines the pore structure and increases matrix density, thus helping to suppress efflorescence and ensure strength. In Comparative Example 3, without the addition of weather-resistant PVA fibers, the flexural strength, compressive strength, and flexural strength retention rate were lower than in Example 3. This suggests that weather-resistant PVA fibers significantly improve flexural toughness primarily by bridging microcracks and preventing crack propagation. Furthermore, the modification of the weather-resistant PVA fibers with antioxidants and UV absorbers also has a certain impact on the overall weather resistance of the inorganic artificial stone. Comparative Example 4, without the addition of modified glass flakes, resulted in lower flexural and compressive strength compared to Example 3, decreased weather resistance retention, and increased water absorption. This indicates that the labyrinth effect of the glass flakes prolongs the diffusion path of corrosive media, and the silane modification on its surface enhances the interfacial bonding with the matrix, improving mechanical properties and delaying the aging process. Comparative Example 5, without reinforcing agent A (i.e., without weather-resistant PVA fibers and modified glass flakes), resulted in lower flexural and compressive strength and weather resistance retention compared to Example 3, increased water absorption, and slight efflorescence. This indicates that the multi-faceted synergistic reinforcement of weather-resistant PVA fibers and modified glass flakes, including toughening, crack resistance, and shielding effects, significantly improves overall performance. Comparative Example 6, without the addition of reinforcing agent B (nano-titanium dioxide and nano-zinc oxide), showed significantly lower weather resistance and flexural strength retention compared to Example 3, and decreased overall performance. This indicates that nano-titanium dioxide and nano-zinc oxide can significantly delay the photo-oxidative aging of materials through ultraviolet shielding and photocatalytic self-cleaning effects, contributing to improved weather resistance of inorganic artificial stone. In Comparative Example 7, no composite accelerator (anhydrous gypsum and trisodium citrate) was added, resulting in lower flexural and compressive strength than in Example 3. The water absorption rate was increased, and the degree of efflorescence reached a moderate level (21%). This indicates that the rapid formation of ettringite by anhydrous gypsum promotes early hydration, while the retarding effect of trisodium citrate ensures workability. The synergistic effect of the two helps to improve the initial density of the green body, thereby inhibiting later efflorescence and improving the final strength.

[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-strength, high-weather-resistant inorganic artificial stone, characterized in that, The inorganic artificial stone comprises the following raw materials in parts by weight: 25-35 parts of low-alkali silicate cement, 8-12 parts of metakaolin, 5-8 parts of silica fume, 25-30 parts of modified coarse aggregate, 10-25 parts of composite fine aggregate, 1-3 parts of reinforcing agent A, 3-7 parts of reinforcing agent B, 2-4 parts of water-reducing agent, 2-5 parts of composite accelerator and early strength agent, 0.5-3 parts of colorant, and 18-25 parts of water; The modified coarse aggregate is hydrophobic modified quartz sand; the reinforcing agent A is obtained by mixing weather-resistant PVA fiber with modified glass flakes; and the reinforcing agent B is a weather-resistant reinforcing agent.

2. The inorganic artificial stone according to claim 1, characterized in that, The preparation method of the hydrophobic modified quartz sand is as follows: Quartz sand is added to treatment solution A and stirred at 50~100 r / min and 90~120℃ for 20~30 min. After filtration, washing and drying, hydrophobic modified quartz sand is obtained.

3. The inorganic artificial stone according to claim 2, characterized in that, The treatment solution A is an aqueous ethanol solution containing 1-3% by mass of γ-methacryloxypropyltrimethoxysilane, and the volume ratio of ethanol to water in the aqueous ethanol solution is (1-3):(7-9).

4. The inorganic artificial stone according to claim 1, characterized in that, The preparation method of the weather-resistant PVA fiber is as follows: an antioxidant and an ultraviolet absorber are added to the PVA spinning solution, and the solution is stirred at a speed of 100~300r / min for 30~60min. After standing and degassing, the solution is spun, stretched and post-treated to obtain the weather-resistant PVA fiber.

5. The inorganic artificial stone according to claim 4, characterized in that, The amount of the antioxidant added accounts for 0.1-1% of the mass of the PVA spinning solution; the amount of the ultraviolet absorber added accounts for 0.1-2% of the mass of the PVA spinning solution.

6. The inorganic artificial stone according to claim 5, characterized in that, The modified glass flakes are prepared by adding glass flakes to treatment solution B, soaking for 30-60 minutes, filtering and drying to obtain modified glass flakes.

7. The inorganic artificial stone according to claim 6, characterized in that, The treatment solution B is an aqueous ethanol solution containing 1-2% by mass of vinyl(β-methoxyethoxy)silane, and the volume ratio of ethanol to water in the aqueous ethanol solution is (1-3):(7-9).

8. The inorganic artificial stone according to claim 1, characterized in that, The composite fine aggregate is obtained by mixing marble powder and calcium carbonate in a mass ratio of (10~15):(4~5).

9. The inorganic artificial stone according to claim 1, characterized in that, The composite coagulation and early strength accelerator is obtained by mixing anhydrous gypsum and trisodium citrate in a mass ratio of (8~9):(1~2).

10. A method for preparing high-strength, high-weather-resistant inorganic artificial stone, characterized in that, The preparation method is used to prepare high-strength, high-weather-resistant inorganic artificial stone as described in any one of claims 1 to 9, and the preparation method includes the following steps: S1. Add low-alkali silicate cement, metakaolin, silica fume, modified coarse aggregate, composite fine aggregate, reinforcing agent A, reinforcing agent B, colorant and composite accelerator to a mixer and mix at a mixing speed of 10~30r / min for 3~5min to obtain a mixture; S2. Add water and water-reducing agent to the mixture, and continue stirring for 5-10 minutes to obtain a slurry; S3. The slurry is laid in the mold and vibrated for 1 to 3 minutes at a vibration frequency of 40 to 60 Hz. After pressure treatment, it is cured for 4 to 8 hours at a temperature of 30 to 50 ℃ and a relative humidity of ≥90%. The mold is then demolded to obtain the blank. S4. After demolding, the blank obtained is cured at room temperature for 3-7 days, and then scraped, sized, and polished to obtain high-strength and high-weather-resistant inorganic artificial stone.

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