Lightweight fireproof polyphenyl granule concrete

Abstract

The invention relates to light fireproof polyphenyl granule concrete, and relates to the technical field of polyphenyl granule concrete raw materials, the polyphenyl granule concrete comprises cement, sand and water, and further comprises fly ash, a water reducing agent and modified polyphenyl granules, and a preparation method of the modified polyphenyl granules comprises the following steps: carrying out surface pretreatment on the polyphenyl granules; carrying out condensation reaction on the silicon source, the phosphorus source and the silane coupling agent to form a composite system; the composite system forms a coating on the surface of the polyphenyl particles subjected to surface pretreatment, and the modified polyphenyl particles are obtained. The polyphenyl granule concrete has the technical effects of light weight, high compressive strength and good fireproof performance.

Description

Technical Field

[0001] This application relates to the field of polystyrene particle concrete raw material technology, and in particular to a lightweight fireproof polystyrene particle concrete. Background Technology

[0002] With the continuous development of society, more and more super high-rise buildings are located in city centers. In order to ensure the personal safety and property security of people, higher requirements must be placed on the materials used in super high-rise buildings. Lightweight aggregate concrete, with its lightweight and multifunctional characteristics, has broad application prospects in projects such as long-span structures, high-rise structures, and earthquake-prone areas. The most common lightweight aggregate concrete is polystyrene particle lightweight concrete. However, while achieving lightweight properties, polystyrene particle lightweight concrete struggles to meet high strength requirements. Therefore, existing technologies for preparing polystyrene particle lightweight concrete often need to address the contradiction between strength and density. For example, the existing technology "CN117263609A" proposes a polystyrene particle lightweight concrete and its preparation method. This concrete uses polystyrene particles to reduce the concrete density to 700~1600 kg / m³. Simultaneously, it uses water-reducing agents, fibers, silica fume, and quartz sand to enhance the concrete strength, achieving a compressive strength of 5~50 MPa. This successfully resolves the contradiction between density and strength, provides good thermal insulation with a thermal conductivity (average temperature 25±2℃) of 0.1~0.3 W / (m·K), exhibits good processability, and uses fly ash, fibers, and water-reducing agents to prevent the lightweight aggregate from floating, delaminating, and cracking. It also demonstrates good material uniformity, excellent workability, cohesiveness, and water retention. Although the concrete prepared using this technology has reduced density and increased compressive strength to some extent, it does not meet the strength requirements for materials used in super high-rise buildings, and there is no relevant data on its construction performance. In addition, the fire rating of general polystyrene particles is only B2, and the fire resistance of polystyrene particle concrete prepared using polystyrene particles is not high. Summary of the Invention

[0003] The purpose of this application is to address the shortcomings of existing polystyrene particle concrete, which suffers from insufficient strength to meet the requirements of high-rise building materials and poor fire resistance. Therefore, this application proposes a lightweight, fire-resistant polystyrene particle concrete. This invention pre-treats the surface of polystyrene particles to form hydrophilic groups, and uses a specific method to prepare a composite sol with flame-retardant properties. The obtained composite sol is then used to impregnate the pre-treated polystyrene particles, forming a dense flame-retardant coating on the particle surface. Applying this flame-retardant coated polystyrene particle to concrete solves the contradiction between strength and density in existing polystyrene particle concrete, while effectively improving compressive strength and fire resistance.

[0004] In the first aspect, the lightweight fireproof polystyrene particle concrete provided in this application adopts the following technical solution: the raw material components of the polystyrene particle concrete include: cement, sand and water, and also include fly ash, water-reducing agent and modified polystyrene particles. The preparation method of the modified polystyrene particles is as follows: the polystyrene particles are subjected to surface pretreatment; a silicon source, a phosphorus source and a silane coupling agent undergo a condensation reaction to form a composite system; the composite system forms a coating on the surface of the pretreated polystyrene particles to obtain modified polystyrene particles.

[0005] Through the above technical solution, the surface of polystyrene particles in the prior art is often hydrophobic, which affects the uniformity and strength of the material. Therefore, the surface of polystyrene particles is pretreated to form hydrophilic groups on the surface of the polystyrene particles. The hydrophilic polystyrene particles are easier to bond with the modified material in the subsequent modification process. At the same time, a composite sol with flame retardant properties and strong interfacial bonding is formed by condensation reaction using silicon source, phosphorus source and silane coupling agent. Then, a coating of composite sol is formed on the surface of the pretreated polystyrene particles. The modified polystyrene particles prepared by this invention can be used in combination with fly ash and water-reducing agent to solve the contradiction between strength and density of polystyrene particle concrete in the prior art, while also having excellent compressive strength and fire resistance.

[0006] In a specific embodiment of the polystyrene particle concrete of the present invention, the cement can be a conventional choice in the art, such as P.O42.5 grade ordinary silicate cement, as long as the cement forms a paste after being mixed with water, can harden in air or better in water, and can firmly bind materials such as sand and modified polystyrene particles together.

[0007] In a specific embodiment of the polystyrene particle concrete of the present invention, the sand can be a conventional choice in the art, such as manufactured sand processed from crushed mine waste rock, with a fineness modulus between 2.3 and 3.0 and an apparent density of 2700 to 2900 kg / m³. 3 .

[0008] In a specific embodiment of the polystyrene particle concrete of the present invention, the fly ash is a fine particulate powder collected from the flue gas after coal combustion in coal-fired power plants. It belongs to industrial solid waste, but after reasonable utilization, it becomes an important green building material and environmentally friendly material. The fly ash used is Class II fly ash.

[0009] In a specific embodiment of the polystyrene particle concrete of the present invention, the water-reducing agent can be a conventional choice in the art, as long as it can improve the fluidity of the concrete mixture, for example, a polycarboxylate high-efficiency water-reducing agent can be used.

[0010] Optionally, the water-reducing agent is 2-acrylamido-2-methylpropanesulfonic acid and / or sodium styrene sulfonate.

[0011] Through the above technical solution, when the water-reducing agent is adjusted to 2-acrylamido-2-methylpropanesulfonic acid and / or sodium styrene sulfonate, the water-reducing agent and the modified polystyrene particles work synergistically to effectively improve the compressive strength of polystyrene particle concrete.

[0012] In a specific embodiment of the polystyrene particle concrete of the present invention, the average particle size of the polystyrene particles is 3-5 mm, and the performance indicators of the polystyrene particles are: apparent density ≤ 6 kg / m³. 3 The polystyrene particles have a thermal conductivity of 0.039 W / (m·K), a tensile strength of 0.12 MPa, a dimensional stability of 0.23%, a combustion rating of B1, a water vapor transmission coefficient of 3.2 ng / (Pa·m·s), a water absorption rate of 2.7%, a compressive strength of 131 kPa, and a fusion bond strength (bending load at break) of 35 N. Using polystyrene particles with appropriate particle size and performance indicators helps reduce the amount of paste used and increase the bulk density, thereby improving the compressive strength of concrete.

[0013] Optionally, the modified polystyrene particles are prepared as follows: polystyrene particles are impregnated in triethanolamine, then the impregnated polystyrene particles are removed and dried to obtain surface-pretreated polystyrene particles; a silicon source, a phosphorus source, and a solvent are mixed, the pH of the mixed system is adjusted to acidic and a first condensation reaction is performed, a silane coupling agent is added to the system after the first condensation reaction and a second condensation reaction is performed to form a composite sol; the surface-pretreated polystyrene particles are impregnated in the composite sol, then the impregnated polystyrene particles are removed and heat-treated to form a coating to obtain modified polystyrene particles.

[0014] By using the above technical solution, pretreating the surface of polystyrene particles with triethanolamine can form hydrophilic groups on the surface of the polystyrene particles, thereby increasing the specific surface area and activity of the polystyrene particles. The silicon source hydrolyzes under acidic conditions to generate silanol groups and form silica sol. The phosphorus source condenses with the silica sol to form Si-OP bonds, which improves the flame retardancy. The added silane coupling agent condenses with the silanol groups of the silica sol, introducing the organic functional groups in the silane coupling agent into the silica sol network, thereby enhancing the interfacial bonding force of the composite sol. By impregnating the polystyrene particles with hydrophilic groups on the surface into the composite sol with strong interfacial bonding force, modified polystyrene particles with flame retardant properties and strong interfacial bonding force can be prepared.

[0015] In a specific embodiment of the method for preparing modified polystyrene particles, the impregnated polystyrene particles are taken out and dried. The drying conditions are: temperature of 60~70℃, specifically, for example, 60℃, 65℃ or 70℃; and time of 0.5~1 h, specifically, for example, 0.5 h, 0.75 h or 1 h.

[0016] Optionally, the silicon source is tetraethyl orthosilicate, the phosphorus source is silicon phosphate, and the silane coupling agent is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and / or methacryloxysilane.

[0017] Through the above technical solution, tetraethyl orthosilicate hydrolyzes under acidic conditions to generate silanol groups and form silica sol. Silicon phosphate condenses with silica sol to form Si-OP bonds, which improves flame retardancy. N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and / or methacryloyloxysilane condense with Si-OH in silica sol, bringing the organic functional groups in N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and / or methacryloyloxysilane into the silica sol network, which can effectively enhance the interfacial bonding force of the composite sol.

[0018] Optionally, the mass ratio of the phosphorus source, the silane coupling agent and the silicon source is 1:1 to 2:2 to 4, specifically, for example, it can be 1:1:2, 1:1:3, 1:2:3 or 1:2:4.

[0019] By adjusting the mass ratio of the phosphorus source, the silane coupling agent, and the silicon source to 1:1~2:2~4, more silica sol can be formed from the silicon source. The silica sol can then undergo condensation reactions with the phosphorus source and the silane coupling agent, respectively, to form a composite sol that simultaneously possesses flame-retardant properties and interface-enhancing capabilities.

[0020] Optionally, the mass ratio of the phosphorus source, the silane coupling agent, and the silicon source is 1:1:2.

[0021] By using the above technical solution, the mass ratio of the phosphorus source, the silane coupling agent and the silicon source is limited to 1:1:2, which can enable the concrete to achieve a compressive strength of over 40 MPa and a flame retardant rating of A1 after 28 days.

[0022] Optionally, the conditions for the first condensation reaction are: a temperature of 55~65 ℃, specifically, for example, 55 ℃, 60 ℃ or 65 ℃, and a time of 2~4 h, specifically, for example, 2 h, 3 h or 4 h; the conditions for the second condensation reaction are: a temperature of 70~85 ℃, specifically, for example, 70 ℃, 75 ℃, 80 ℃ or 85 ℃, and a time of 6~10 h, specifically, for example, 6 h, 8 h or 10 h.

[0023] Through the above technical solution, the silicon source is hydrolyzed under acidic conditions to generate silanol groups and form silica sol. The phosphorus source and silica sol are stirred and hydrolyzed at a temperature of 55~65 ℃ for 2~4 h to form Si-OP bonds (first condensation reaction), resulting in a silica sol-phosphorus source mixed sol, which improves flame retardancy. The silane coupling agent is condensed with the silanol groups of the silica sol in the system after the first condensation reaction at a temperature of 70~85 ℃ for 6~10 h, introducing the organic functional groups in the silane coupling agent into the silica sol network and enhancing the interfacial bonding force of the composite sol.

[0024] Optionally, the specific method of the heat treatment is as follows: the impregnated polystyrene particles are dried at 55~65 ℃ for 0.5~1 h, the dried polystyrene particles are heated at 90~110 ℃ for 1~2 h, and finally the heated polystyrene particles are treated at 140~160 ℃ for 0.5~1 h.

[0025] The purpose of drying the impregnated polystyrene particles at 55-65 ℃ for 0.5-1 h is to allow the solvent in the colloid to fully evaporate. The purpose of heating the dried polystyrene particles at 90-110 ℃ for 1-2 h is to promote the condensation of silica sol to form a dense coating. The purpose of treating the heated polystyrene particles at 140-160 ℃ for 0.5-1 h is to further enhance the chemical bonding between the silica sol and the phosphorus source, thereby effectively improving the interfacial reinforcement ability of the composite sol.

[0026] Optionally, the thickness of the coating is 50~100 μm, specifically, for example, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm.

[0027] By using the above technical solution, the thickness of the coating is controlled to be 50~100 μm, and the modified polystyrene particles obtained in the final preparation are applied to concrete, which can effectively improve the compressive strength and fire resistance of the concrete while making it lightweight.

[0028] Optionally, based on the weight of each cubic meter of the polystyrene particle concrete, the raw material components of the polystyrene particle concrete include: cement at 200~300 kg / m³. 3 Fly ash content is 90~150 kg / m³ 3 The sand content is 600~1200 kg / m³ 3 The water-reducing agent is 3~10 kg / m³. 3 Water content is 200~230 kg / m³ 3 The modified polystyrene particles have a density of 3~5 kg / m³. 3 .

[0029] By adjusting the components of each raw material in concrete using the above technical solutions, the workability of concrete can be improved, which is beneficial for pumping large-span structures and high-rise buildings, and can also effectively improve the compressive strength of concrete.

[0030] In summary, this application includes at least one of the following beneficial technical effects: 1. This invention utilizes a specific method to prepare modified polystyrene particles with flame-retardant properties and interface-enhancing capabilities. The modified polystyrene particles, in synergy with fly ash and water-reducing agents, resolve the contradiction between the strength and density of polystyrene particle concrete, while also exhibiting good workability, thermal insulation, and fire resistance. 2. In preferred cases, by further defining the preparation conditions of the modified polystyrene particles and the composition of fly ash and water-reducing agent, the compressive strength and fire resistance of concrete can be effectively improved.

[0031] The present application will be further described in detail below with reference to specific embodiments.

[0032] The following examples further illustrate the lightweight fire-resistant polystyrene particle concrete of the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0033] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0034] Cement: Purchased from Hebei Chengda Environmental Protection Technology Co., Ltd., Product No.: Diamond Brand P.O42.5 Cement; Sand: Purchased from Fengning Xinyuan Mining Co., Ltd., Product No.: Zone II Medium Sand; Fly Ash: Purchased from Langfang Thermal Power Plant of China Energy Investment Corporation North China Electric Power Co., Ltd., Specification: Grade II Fly Ash; Water Reducing Agent: 2-Acrylamido-2-Methylpropanesulfonic Acid, Purchased from Shouguang Lianmeng Petrochemical Co., Ltd.; Polystyrene Particles: Purchased from Hebei Baoding Mingcheng Hengyuan Building Materials Sales Co., Ltd., Average Particle Size: 2~4mm; Silane Coupling Agent: N-(2-Aminoethyl)-3-Aminopropyltrimethoxysilane, Purchased from Hubei Jianghan New Materials Co., Ltd.

[0035] Preparation Example 1 Preparation of modified polystyrene particles: 5.0 kg of polystyrene particles were immersed in 10 L of 3% triethanolamine solution (triethanolamine solution is a mixture of triethanolamine and water) for 1 h. Then, the immersed polystyrene particles were taken out and dried at 60 °C for 30 min to obtain surface-pretreated polystyrene particles. 1.0 kg of tetraethyl orthosilicate and 0.5 kg of silicon phosphate were mixed. Then, 15 L of ethanol solution (a mixture of anhydrous ethanol and water with a concentration of 30%) was added to the mixture to form a mixed system. Acetic acid was added to the mixed system to adjust the pH to 4, and the mixture was stirred in a 60 °C water bath for 3 h to carry out the first condensation reaction, forming a silica sol-silicon phosphate mixed sol. 0.5 kg of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was added to 9.5 kg of the silica sol-silicon phosphate mixed sol, and the temperature was raised to 80 °C. The second condensation reaction was carried out at 80 °C for 8 h to form a composite sol. Three kg of the pretreated polystyrene particles were immersed in six kg of the composite sol and pulled at a speed of 0.5 m / min to form a uniform wet film on the surface of the polystyrene particles. The polystyrene particles with the uniform wet film were first dried at 60 °C for 30 min, then heated at 100 °C for 1 h, and finally treated at 150 °C for 0.5 h to obtain modified polystyrene particles with a surface coating thickness of 80 μm.

[0036] Preparation Example 2 The preparation method is the same as in Example 1, except that the silane coupling agent is methacryloxysilane.

[0037] Preparation Example 3 The preparation was carried out in the same manner as in Example 1, except that the first condensation reaction was carried out by stirring in a water bath at 55 °C for 4 h, and the second condensation reaction was carried out at 70 °C for 6 h.

[0038] Comparative Preparation Example 1 The preparation method of Example 1 was followed, except that no surface pretreatment of the polystyrene particles was performed. Specifically: 1.0 kg of tetraethyl orthosilicate and 0.5 kg of silicon phosphate were mixed. Then, 15 L of ethanol solution (a mixture of anhydrous ethanol and water with a concentration of 30%) was added to the mixture to form a mixed system. Acetic acid was added to the mixed system to adjust the pH to 4, and the mixture was stirred in a 60 °C water bath for 3 h to carry out the first condensation reaction, forming a silica sol-silicon phosphate mixed sol. 0.5 kg of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was added to 9.5 kg of the silica sol-silicon phosphate mixed sol, and the temperature was raised to 80 °C. The second condensation reaction was carried out at 80 °C for 8 h to form a composite sol. Three kg of polystyrene particles were immersed in 6 kg of the composite sol and pulled at a speed of 0.5 m / min to form a uniform wet film on the surface of the polystyrene particles. The polystyrene particles with the uniform wet film were first dried at 60 °C for 30 min, and then heated at 100 °C for 1 h. Finally, the heated polystyrene particles were treated at 150 °C for 0.5 h to obtain modified polystyrene particles with a surface coating thickness of 80 μm.

[0039] Comparative Preparation Example 2 The preparation method of Example 1 was followed, except that the silane coupling agent was replaced with a silicon source, specifically: 5.0 kg of polystyrene particles were immersed in 10 L of 3% triethanolamine solution (triethanolamine solution is a mixture of triethanolamine and water) for 1 h. Then, the immersed polystyrene particles were taken out and dried at 60 °C for 30 min to obtain surface-pretreated polystyrene particles. 1.0 kg of tetraethyl orthosilicate and 0.5 kg of silicon phosphate were mixed. Then, 15 L of ethanol solution (a mixture of anhydrous ethanol and water with a concentration of 30%) was added to the mixture to form a mixed system. Acetic acid was added to the mixed system to adjust the pH to 4, and the mixture was stirred in a 60 °C water bath for 3 h to carry out the first condensation reaction, forming a silica sol-silicon phosphate mixed sol. 0.5 kg of tetraethyl orthosilicate was added to 9.5 kg of the silica sol-silicon phosphate mixed sol, and the temperature was raised to 80 °C and reacted at 80 °C for 8 h to form a composite sol. Three kg of the pretreated polystyrene particles were immersed in six kg of the composite sol and pulled at a speed of 0.5 m / min to form a uniform wet film on the surface of the polystyrene particles. The polystyrene particles with the uniform wet film were first dried at 60 °C for 30 min, then heated at 100 °C for 1 h, and finally treated at 150 °C for 0.5 h to obtain modified polystyrene particles with a surface coating thickness of 60 μm. Example 1

[0040] A lightweight fire-resistant polystyrene particle concrete, wherein the raw material components of the polystyrene particle concrete, based on the weight of each cubic meter of the polystyrene particle concrete, include: 280 kg / m³ of cement. 3 120 kg / m³ of fly ash 3 900 kg / m³ of sand 3 Water-reducing agent (a mixture of 2-acrylamido-2-methylpropanesulfonic acid and sodium styrene sulfonate, wherein the mass ratio of 2-acrylamido-2-methylpropanesulfonic acid to sodium styrene sulfonate is 2:1) 7 kg / m 3 220 kg / m³ of water3 The modified polystyrene particles prepared in Example 1 were 5 kg / m³. 3 .

[0041] Example 2 The procedure was carried out in accordance with Example 1, except that the modified polystyrene particles prepared in Preparation Example 1 were replaced with the modified polystyrene particles prepared in Preparation Example 2.

[0042] Example 3 The procedure was carried out in accordance with Example 1, except that the modified polystyrene particles prepared in Preparation Example 1 were replaced with the modified polystyrene particles prepared in Preparation Example 3.

[0043] Comparative Example 1 The procedure was carried out as described in Example 1, except that 5 kg / m 3 Preparation Example 1: The modified polystyrene particles prepared were replaced with 5 kg / m³ 3 Polystyrene particles.

[0044] Comparative Example 2 The procedure was carried out as described in Example 1, except that 120 kg / m 3 The fly ash was replaced with 120 kg / m³ 3 The water-reducing agent (2-acrylamido-2-methylpropanesulfonic acid and sodium styrene sulfonate in a mass ratio of 2:1) in the lightweight fireproof polystyrene particle concrete totals 127 kg / m³. 3 Water-reducing agent.

[0045] Comparative Example 3 The procedure was carried out as described in Example 1, except that 7 kg / m 3 The water-reducing agent was replaced with 7 kg / m³ 3 The fly ash in the lightweight fireproof polystyrene particle concrete totals 127 kg / m³. 3 fly ash.

[0046] Comparative Example 4 The procedure was carried out as described in Example 1, except that 5 kg / m 3 Preparation Example 1: The modified polystyrene particles prepared were replaced with 5 kg / m³ 3 Compare the modified polystyrene particles prepared in Preparation Example 1.

[0047] Comparative Example 5 The procedure was carried out as described in Example 1, except that 5 kg / m 3 Preparation Example 1: The modified polystyrene particles prepared were replaced with 5 kg / m³ 3 Compare the modified polystyrene particles prepared in Preparation Example 2.

[0048] Test case Dry apparent density: Tested according to JGJ51-2002 "Technical Specification for Lightweight Aggregate Concrete"; Compressive strength: Tested according to GB / T 50081-2019 "Test Methods for Physical and Mechanical Properties of Concrete" at a standard curing age of 28 days. Thermal conductivity: average temperature 25 ℃, according to JGJ51-2002 "Technical Specification for Lightweight Aggregate Concrete"; Construction performance: Initial slump, spread, and air release time were all tested according to GB / T 50080-2016 "Test Methods for Performance of Concrete Mixtures"; Flame retardancy: The test method is GB / T8624-2012 "Classification of Combustion Performance of Building Materials and Products". Flame retardancy level: A1: Non-combustible material; A2: Non-combustible material, but may release toxic fumes under certain conditions; B1: Flame-retardant material; B2: Combustible material; B3: Flammable material.

[0049] The concrete prepared using Examples 1-3 and Comparative Examples 1-5 were tested for dry apparent density, compressive strength, thermal conductivity, workability, and flame retardancy. The test results are shown in Table 1. Table 1

[0050] As shown in Table 1, when the modified polystyrene particles prepared by the method of the present invention are used in combination with fly ash and water-reducing agents, the concrete can not only solve the contradiction between strength and density in the existing polystyrene particle concrete, but also have excellent compressive strength and fire resistance, as well as good workability and thermal insulation performance. However, if no surface pretreatment is performed when preparing the modified polystyrene particles, the bonding force between the polystyrene particles and the composite sol is weak, resulting in weak flame retardancy and interfacial bonding ability of the prepared modified polystyrene particles. Therefore, the compressive strength and flame retardancy of the prepared concrete are not good. Furthermore, if the silane coupling agent is replaced with a silicon source when preparing the modified polystyrene particles, the interfacial bonding force of the prepared modified polystyrene particles will be reduced, resulting in low compressive strength of the prepared concrete.

[0051] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A lightweight fireproof polystyrene aggregate concrete, raw material components of the polystyrene aggregate concrete comprising: Cement, sand and water, characterized in that it further comprises fly ash, water reducing agent and modified polystyrene particles, wherein the modified polystyrene particles are prepared by: surface pretreatment of polystyrene particles; condensation reaction of a silicon source, a phosphorus source and a silane coupling agent to form a composite system; and formation of a coating on the surface of the surface pretreated polystyrene particles by the composite system to obtain the modified polystyrene particles.

2. Lightweight fireproof polyphenyl granulate concrete according to claim 1, characterized in that, The modified polystyrene particles are prepared by: immersing polystyrene particles in triethanolamine, then taking out the immersed polystyrene particles and drying to obtain surface pretreated polystyrene particles; mixing a silicon source, a phosphorus source and a solvent, adjusting the pH value of the mixed system to be acidic and performing a first condensation reaction, adding a silane coupling agent to the system after the first condensation reaction and performing a second condensation reaction to form a composite sol; immersing the surface pretreated polystyrene particles in the composite sol, then taking out the immersed polystyrene particles and performing a heating treatment to form a coating to obtain the modified polystyrene particles.

3. Lightweight fireproof polyphenyl granulate concrete according to claim 2, characterized in that, The silicon source is tetraethyl orthosilicate, the phosphorus source is silicon phosphate, and the silane coupling agent is N-(2-aminoethyl)-3-aminopropyl trimethoxysilane and / or methacryloyloxysilane.

4. Lightweight fireproof polyphenyl granulate concrete according to claim 2 or 3, characterized in that The first condensation reaction is performed at a temperature of 55-65 ℃ for 2-4 h, and the second condensation reaction is performed at a temperature of 70-85 ℃ for 6-10 h.

5. Lightweight fireproof polyphenyl granulate concrete according to claim 2 or 3, characterized in that, The heating treatment is performed by drying the immersed polystyrene particles at 55-65 ℃ for 0.5-1 h, then heating the dried polystyrene particles at 90-110 ℃ for 1-2 h, and finally treating the heated polystyrene particles at 140-160 ℃ for 0.5-1 h.

6. The lightweight fireproof polyphenyl granulate concrete according to claim 1 or 2, characterized in that, The thickness of the coating is 50-100 μm.

7. Lightweight fireproof polyphenyl granulate concrete according to claim 2 or 3, characterized in that, The mass ratio of the phosphorus source, the silane coupling agent and the silicon source is 1:1-2:2-4.

8. Lightweight fireproof polyphenyl granulate concrete according to claim 1 or 2, characterized in that The mass ratio of the phosphorus source, the silane coupling agent and the silicon source is 1:1:

2.

9. The lightweight fireproof polyphenyl granulate concrete according to claim 1, characterized by that The water reducing agent is 2-acrylamido-2-methylpropanesulfonic acid and / or sodium styrene sulfonate.

10. The lightweight fireproof polyphenyl particle concrete according to claim 1, wherein The raw material components of the polystyrene particle concrete include cement 200-300 kg / m 3 , fly ash 90-150 kg / m 3 , sand 600-1200 kg / m 3 , water reducing agent 3-10 kg / m 3 , water 200-230 kg / m 3 , and modified polystyrene particles 3-5 kg / m 3 .

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