Cement-based thermal insulation material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of building materials, and particularly discloses a cement-based thermal insulation material as well as a preparation method and application thereof. According to the invention, resources such as waste tire rubber, steel slag, coal gangue, bagasse and coconut shell are effectively utilized, and rubber and coconut fiber are correspondingly modified and reasonably matched with other raw materials, so that the cement-based thermal insulation material with excellent mechanical properties and thermal insulation properties is provided; the method has good economic benefits, environmental protection benefits and social benefits. The invention further provides a preparation method of the cement-based thermal insulation material. The preparation method has the advantages that the preparation process is simple, raw materials are easy to obtain, popularization and application are easy, and the obtained material is stable in performance. The method can be applied to the field of preparation of thermal insulation building walls.

Description

Technical Field

[0001] The invention belongs to the field of building materials, and in particular relates to a cement-based thermal insulation material, a preparation method and application thereof. Background Art

[0002] The construction industry is a pillar industry in my country, and building energy consumption accounts for about 1 / 3 of the total social energy consumption. With the improvement of people's requirements for building comfort and the acceleration of urbanization, my country's building energy consumption has shown a rapid growth trend and consumed a large amount of natural resources. The increase in energy consumption and the depletion of resources are severe challenges facing mankind. The implementation of a series of building energy-saving policies has promoted the rapid development of thermal insulation materials in the construction industry. Cement-based materials are one of the most widely used building materials in the construction industry. Thermal insulation materials developed based on cement, especially cement-based thermal insulation wall materials developed based on the recycling of waste resources, are of great significance.

[0003] A large amount of steel slag and coal gangue resources in my country cannot be effectively treated, which not only occupies a large amount of land resources, but also seriously pollutes the surrounding environment. According to statistics, about 4 billion tons of tire waste are produced every year worldwide, which causes great harm to the environment due to its non-biodegradability. Therefore, comprehensive utilization of waste steel slag, coal gangue and waste tires and other resources, and development of a new type of cement-based building insulation material and product to address the common shortcomings of cement-based materials such as low flexural strength and poor thermal insulation effect, meet the requirements of building energy-saving buildings for low-carbon economy and energy-saving and emission reduction, and are of great significance to the sustainable development of my country's economy. Summary of the invention

[0004] In view of the shortcomings of low tensile strength and poor thermal insulation effect commonly found in cement-based materials in the prior art, the present invention comprehensively utilizes waste resources such as waste tire rubber, steel slag, coal gangue, bagasse and coconut shell to provide a cement-based thermal insulation material, which improves its flexural strength and thermal insulation performance while meeting the requirements of specific mechanical properties and other indicators, and has good economic and social benefits.

[0005] The second object of the present invention is to provide a method for preparing the above-mentioned cement-based thermal insulation material, and to provide a production scheme suitable for promotion for the preparation of the cement-based thermal insulation material.

[0006] The third object of the present invention is to provide the application of the above-mentioned cement-based thermal insulation material to provide more choices for the selection of thermal insulation building walls.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: In a first aspect, the present invention provides a cement-based thermal insulation material, which comprises the following components in parts by weight: 70 to 76 parts of thermal insulation and environmentally friendly cement, 19 to 22 parts of polystyrene foam particles, 3 to 6 parts of sulfuric acid-modified rubber, 1.5 to 2.5 parts of plant fiber composite, 3 to 5 parts of gypsum and 0.18 to 0.23 parts of water reducing agent; Wherein, the thermal insulation and environmentally friendly cement contains a modified alcoholamine compound; The modified alcoholamine compound is obtained by polymerizing an intermediate obtained by the reaction of pyromellitic anhydride and alcoholamine substances with acrylic acid and methyl allyl alcohol polyoxyethylene ether; The plant fiber composite comprises bagasse fiber and modified coconut shell fiber.

[0008] The present invention provides a novel cement-based thermal insulation material, which belongs to a rubber-fiber-cement composite material. The addition of plant fiber composite and sulfuric acid-modified rubber enables plant fiber and rubber powder to be more effectively combined with cement, and significantly improves the adhesion between plant fiber and cement and between rubber and cement. Compared with cement-based composite materials without sulfuric acid-modified rubber, the water absorption rate and thermal conductivity of the cement-based thermal insulation material provided by the present invention are significantly reduced. Compared with cement-based composite materials without modified coconut shell fibers, the water absorption of the cement-based thermal insulation material provided by the present invention is significantly reduced, which has a positive effect on improving the mechanical properties and durability of the material.

[0009] The modified alcoholamine compound used as a grinding aid is prepared by polymerizing an intermediate obtained by the reaction of pyromellitic anhydride and alcoholamine substances with acrylic acid and methyl allyl alcohol polyoxyethylene ether under the action of an initiator benzoyl peroxide; the modified alcoholamine compound has a highly polar functional group and can be adsorbed on the surface of cement particles to form an adsorption film, thereby shielding the attraction between particles and preventing fine particles from reaggregating, and can also promote the formation and expansion of particle cracks, increase the fluidity of cement raw material particles, and make the particles have equal opportunities to be ground, thereby helping to improve the grinding efficiency, optimize the particle size distribution, and improve the dispersibility of the particles.

[0010] According to statistics, around 1 billion tires reach the end of their service life every year, generating about 4 billion tons of tire waste worldwide. Most of them are disposed of by landfill because they are non-biodegradable, which not only causes environmental pollution but also spreads diseases because they provide breeding grounds for pests and insects. Although it has been reported that waste tires can be used as aggregate substitutes in cement-based composites, due to the hydrophobic properties of waste tire rubber, the remaining cement bodies have poor adhesion, resulting in a significant reduction in the strength of cement-based composites. The present invention can make the rubber surface rougher by modifying waste tire rubber particles with sulfuric acid of an appropriate concentration, improve the interface bonding between rubber and cement slurry, and thus improve the bonding performance with the cement matrix. Preliminary experiments have shown that when applied to cement-based materials, sulfuric acid-modified rubber has better comprehensive performance than potassium permanganate-modified rubber.

[0011] As a first limitation of the above-mentioned cement-based thermal insulation material, the thermal insulation and environmentally friendly cement also includes limestone, steel slag, diatomaceous earth, vermiculite, gypsum and coal gangue.

[0012] As a further limitation of the first limitation of the above-mentioned cement-based thermal insulation material, the thermal insulation and environmentally friendly cement includes the following components in parts by weight: 70 to 80 parts of limestone, 3 to 6 parts of steel slag, 1 to 3 parts of diatomaceous earth, 2 to 4 parts of vermiculite, 0.8 to 1.6 parts of gypsum, 6 to 10 parts of coal gangue and 0.4 to 0.6 parts of modified alcohol amine compound.

[0013] Steel slag is an industrial waste discharged during the steelmaking process, and its amount is about 8% to 12% of steel production. Since a large amount of steel slag has not been processed in time, it has brought a heavy burden to mankind, such as occupying a large amount of land, polluting air and water sources, etc. Therefore, it is necessary to conduct research on the reduction, resource utilization and high-value comprehensive utilization of steel slag to turn waste into treasure, so as to achieve the purpose of making full use of steel slag and reducing the pollution of the steel industry to the environment. Coal gangue is an industrial waste slag with a wide range of sources and a relatively low price, and its comprehensive utilization rate needs to be further improved. The present invention is reasonably compounded to turn waste into treasure, and provides an effective way to comprehensively utilize industrial waste slag such as steel slag and coal gangue, which has good economic benefits, environmental benefits and social benefits.

[0014] As another limitation of the first limitation of the above-mentioned cement-based thermal insulation material, the preparation method of the thermal insulation and environmentally friendly cement comprises the following steps: S1. The limestone and vermiculite are crushed separately to obtain corresponding granular materials with a particle size not exceeding 2 cm; mixed according to the ratio to obtain a granular material mixture; S2: coarsely grinding the granular material mixture, adding the steel slag, diatomaceous earth and the first part of the modified alcoholamine compound, and grinding to obtain cement raw material; S3. The raw cement material is dried and fired at a firing temperature of 1300 ℃ ~ 1400 ℃, a firing time of 35min ~ 45min, cooled, rolled, broken up, and the remaining portion of the modified alcoholamine compound is added for grinding to obtain cement clinker; S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0015] Preferably, in step S2, the weight of the first part of the modified ethanolamine compound accounts for 60% to 70% of the total amount of the modified ethanolamine compound.

[0016] The preparation method of the thermal insulation and environmentally friendly cement provided by the present invention adds a grinding aid modified alcohol amine compound in two steps in the conventional cement preparation method, which is beneficial to improving the stability of cement raw materials and cement clinker out of the mill [Z1]. In addition, the raw materials used are inexpensive and easily available, providing a feasible solution for the comprehensive utilization and resource utilization of steel slag and coal gangue.

[0017] As a second limitation of the above-mentioned cement-based thermal insulation material, the preparation method of the sulfuric acid-modified rubber comprises: soaking waste tire particles in 8wt%~10wt% sulfuric acid for 2h~3h; the diameter of the waste tire particles used is 2mm~4mm.

[0018] As a third limitation of the above-mentioned cement-based thermal insulation material, the modified coconut shell fiber is obtained by modifying coconut shell fiber with stearic acid, and the specific preparation method comprises: adding 300 parts of water and 8 parts to 12 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, and soaking in a water bath of 60° C. to 65° C. for 4 h to 6 h to obtain the modified coconut shell fiber.

[0019] Natural fibers absorb water from the system, which can affect cement hydration and its effective performance. In the present invention, stearic acid, a saturated organic acid, is used as a surface modifier for plant fibers, which can interact with the hydroxyl groups in coconut shell fibers, facilitate their adhesion and expose the hydrophobic part, thereby improving their hydrophobic properties. Coconut shell fibers have better fiber-matrix interface adhesion after being treated with stearic acid. After adding modified coconut shell fibers, cement-based thermal insulation materials can have better strength and toughness.

[0020] As a fourth limitation of the above-mentioned cement-based thermal insulation material, the weight ratio of the bagasse fiber to the modified coconut shell fiber is 1:2-4.

[0021] In a second aspect, the present invention also provides a method for preparing the above-mentioned cement-based thermal insulation material, the preparation method comprising mixing the thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, plant fiber composite, gypsum and water reducer to obtain the cement-based thermal insulation material.

[0022] The preparation method of the cement-based thermal insulation material provided by the present invention has the advantages of simple preparation process, readily available raw materials, easy promotion and application, and stable performance of the obtained material.

[0023] In a third aspect, the present invention also provides application of the above-mentioned cement-based thermal insulation material in thermal insulation walls.

[0024] Since the cement-based thermal insulation material provided by the present invention has excellent thermal insulation performance, it can be widely used in the field of thermal insulation building walls. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The steel slag used in the present invention complies with GB / T 20491-2017.

[0027] Example 1 [Z2] This embodiment provides a cement-based thermal insulation material, which includes the following components in parts by weight: 70 parts of environmentally friendly cement, 19 parts of polystyrene foam particles, 3 parts of sulfuric acid-modified rubber, 2.5 parts of plant fiber composite, 3 parts of gypsum and 0.18 parts of sodium lignin sulfonate; The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 75 parts of limestone, 4 parts of steel slag, 2 parts of diatomaceous earth, 3 parts of vermiculite, 1 part of gypsum, 8 parts of coal gangue and 0.5 parts of modified alcoholamine compound; The plant fiber composite is prepared by compounding bagasse fiber and modified coconut shell fiber in a weight ratio of 1:3.

[0028] The preparation method of the above-mentioned raw materials is as follows.

[0029] (1) The preparation method of the modified alcoholamine compound comprises the following steps: Step 1: add pyromellitic anhydride and triethanolamine into a container in a molar ratio of 1:3, add an appropriate amount of toluenesulfonic acid, mix well, and react at 120° C. for 4.5 hours to obtain an intermediate for standby use; Step 2: Add the intermediate, pyromellitic anhydride, methyl allyl alcohol polyoxyethylene ether and acrylic acid in a mass ratio of 5:1:3.5:3.5 to the reactor in sequence, and then add appropriate amounts of 2,4-diphenyl-4-methyl-1-pentene and benzoyl peroxide at 80°C, and control 2,4-diphenyl-4-methyl-1-pentene and ammonium persulfate to account for 0.5% and 2.1% of the mass of methyl allyl alcohol polyoxyethylene ether, respectively. After the addition is completed, react at 65°C for 4.5h. After the reaction is completed, adjust the pH value to 7 with 30% sodium hydroxide to obtain the modified alcoholamine compound.

[0030] (2) The method for preparing the thermal insulation and environmentally friendly cement comprises the following steps: S1. The limestone and vermiculite are crushed separately to obtain corresponding granular materials with a particle size not exceeding 2 cm; mixed according to the ratio to obtain a granular material mixture; S2. The granular material mixture was crushed to a particle size of 30 to 80 mm using a jaw crusher, and the steel slag, diatomaceous earth and a total amount of 60% of the modified alcohol amine compound were added and mixed evenly, ground with a ball mill, and the residue was not more than 10% through a 40 μm square hole sieve to obtain cement raw material; S3. The raw cement material is dried and fired at a firing temperature of 1300 ° C and a firing time of 45 min, and then rapidly cooled in a grate cooler, followed by roller pressing, breaking up, and then grinding the remaining portion of the modified alcoholamine compound to obtain cement clinker; S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0031] (3) The method for preparing bagasse fiber comprises the following steps: The bagasse was chopped and bagasse fibers with a length of 2 mm to 4 mm and a diameter not greater than 0.2 mm were selected and dried in an oven at 105°C for 4 h.

[0032] (4) The preparation method of the modified coconut shell fiber comprises the following steps: Add 300 parts of water and 10 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, soak in a water bath at 65° C. for 4 hours, wash, and dry under reduced pressure at 80° C. for 2 hours to obtain modified coconut shell fiber; (5) The preparation method of the sulfuric acid modified rubber comprises the following steps: taking waste tire particles with a diameter of 2 mm to 4 mm and no impurities on the surface, soaking them in an 8% sulfuric acid solution of 3 times the weight of the waste tire particles for 2 hours to modify their surfaces, and drying them to obtain the sulfuric acid modified rubber.

[0033] This embodiment also provides a preparation method of the above-mentioned cement-based thermal insulation material, and the preparation method comprises the following steps: mixing the above-mentioned thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, bagasse fiber, modified coconut shell fiber, gypsum and water reducer to obtain a cement-based thermal insulation material, which is recorded as cement-based thermal insulation material I.

[0034] Example 2 This embodiment provides a cement-based thermal insulation material, which includes the following components in parts by weight: 76 parts of environmentally friendly cement, 22 parts of polystyrene foam particles, 6 parts of sulfuric acid-modified rubber, 2 parts of plant fiber composite, 5 parts of gypsum and 0.23 parts of sodium lignin sulfonate; The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 70 parts of limestone, 6 parts of steel slag, 3 parts of diatomaceous earth, 2 parts of vermiculite, 0.8 parts of gypsum, 6 parts of coal gangue and 0.4 parts of modified alcoholamine compound; The plant fiber composite is prepared by compounding bagasse fiber and modified coconut shell fiber in a weight ratio of 1:2.

[0035] The preparation method of the above-mentioned raw materials is as follows.

[0036] (1) The preparation method of the modified alcoholamine compound comprises the following steps: Step 1: add pyromellitic anhydride and triethanolamine in a molar ratio of 1:3.5 into a container, add an appropriate amount of toluenesulfonic acid, mix well, and react at 115° C. for 5 hours to obtain an intermediate for standby use; Step 2: Add the intermediate, pyromellitic anhydride, methyl allyl alcohol polyoxyethylene ether and acrylic acid in a mass ratio of 5:1:4:4 to the reactor in sequence, and then add appropriate amounts of 2,4-diphenyl-4-methyl-1-pentene and benzoyl peroxide at 80°C, and control 2,4-diphenyl-4-methyl-1-pentene and ammonium persulfate to account for 0.5% and 2.0% of the mass of methyl allyl alcohol polyoxyethylene ether, respectively. After the addition is completed, react at 62°C for 5h. After the reaction is completed, adjust the pH value to 7 with 30% sodium hydroxide to obtain the modified alcohol amine compound.

[0037] (2) The method for preparing the thermal insulation and environmentally friendly cement comprises the following steps: S1. The limestone and vermiculite are crushed separately to obtain corresponding granular materials with a particle size not exceeding 2 cm; mixed according to the ratio to obtain a granular material mixture; S2. The granular material mixture was crushed to a particle size of 30 to 80 mm using a jaw crusher, and the steel slag, diatomaceous earth and a total amount of 70% of the modified alcohol amine compound were added and mixed evenly, ground with a ball mill, and the residue was not more than 10% through a 40 μm square hole sieve to obtain cement raw material; S3. The raw cement material is dried and fired at a firing temperature of 1400 ° C and a firing time of 35 min, and then rapidly cooled in a grate cooler, followed by rolling, breaking up, and grinding the remaining portion of the modified alcoholamine compound again to obtain cement clinker; S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0038] (3) The method for preparing bagasse fiber comprises the following steps: The bagasse was chopped and bagasse fibers with a length of 2 mm to 4 mm and a diameter not greater than 0.2 mm were selected and dried in an oven at 105°C for 4 h.

[0039] (4) The preparation method of the modified coconut shell fiber comprises the following steps: Add 300 parts of water and 8 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, soak in a 60° C. water bath for 6 hours, wash, and dry under reduced pressure at 80° C. for 2 hours to obtain modified coconut shell fiber; (5) The preparation method of the sulfuric acid modified rubber comprises the following steps: taking waste tire particles with a diameter of 2 mm to 4 mm and no impurities on the surface, soaking them in a 10% sulfuric acid solution of 3 times the weight of the waste tire particles for 3 hours to modify their surfaces, and drying them to obtain the sulfuric acid modified rubber.

[0040] This embodiment also provides a method for preparing the above-mentioned cement-based thermal insulation material, and the preparation method comprises the following steps: mixing the above-mentioned thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, bagasse fiber, modified coconut shell fiber, gypsum and water reducer to obtain a cement-based thermal insulation material, which is recorded as cement-based thermal insulation material II.

[0041] Example 3 This embodiment provides a cement-based thermal insulation material, which includes the following components in parts by weight: 74 parts of environmentally friendly cement, 21 parts of polystyrene foam particles, 5 parts of sulfuric acid-modified rubber, 1.5 parts of plant fiber composite, 4 parts of gypsum and 0.2 parts of sodium lignin sulfonate; The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 80 parts of limestone, 3 parts of steel slag, 1 part of diatomaceous earth, 4 parts of vermiculite, 1.6 parts of gypsum, 10 parts of coal gangue and 0.6 parts of modified alcoholamine compound; The plant fiber composite is prepared by compounding bagasse fiber and modified coconut shell fiber in a weight ratio of 1:4.

[0042] The preparation method of the above-mentioned raw materials is as follows.

[0043] (1) The preparation method of the modified alcoholamine compound comprises the following steps: Step 1: add pyromellitic anhydride and triethanolamine into a container in a molar ratio of 1:4, add an appropriate amount of toluenesulfonic acid, mix well, and react at 120° C. for 4.5 hours to obtain an intermediate for standby use; Step 2: Add the intermediate, pyromellitic anhydride, methyl allyl alcohol polyoxyethylene ether and acrylic acid in a mass ratio of 4:1:3.8:3.5 to the reactor in sequence, and then add appropriate amounts of 2,4-diphenyl-4-methyl-1-pentene and benzoyl peroxide at 80°C, and control 2,4-diphenyl-4-methyl-1-pentene and ammonium persulfate to account for 0.5% and 2.0% of the mass of methyl allyl alcohol polyoxyethylene ether, respectively. After the addition is completed, react at 65°C for 4.5h. After the reaction is completed, adjust the pH value to 7 with 30% sodium hydroxide to obtain the modified alcoholamine compound.

[0044] (2) The method for preparing the thermal insulation and environmentally friendly cement comprises the following steps: S1. The limestone and vermiculite are crushed separately to obtain corresponding granular materials with a particle size not exceeding 2 cm; mixed according to the ratio to obtain a granular material mixture; S2. The granular material mixture was crushed to a particle size of 30 to 80 mm using a jaw crusher, and the steel slag, diatomaceous earth and a total amount of 65% of the modified alcohol amine compound were added and mixed evenly, ground with a ball mill, and the residue was not more than 10% through a 40 μm square hole sieve to obtain cement raw material; S3. The raw cement material is dried and fired at a firing temperature of 1350 ° C and a firing time of 40 min, and then rapidly cooled in a grate cooler, followed by rolling, breaking up, and then adding the remaining portion of the modified alcoholamine compound to grind to obtain cement clinker; S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0045] (3) The method for preparing bagasse fiber comprises the following steps: The bagasse was chopped and bagasse fibers with a length of 2 mm to 4 mm and a diameter not greater than 0.2 mm were selected and dried in an oven at 105°C for 4 h.

[0046] (4) The preparation method of the modified coconut shell fiber comprises the following steps: Add 300 parts of water and 12 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, soak in a water bath at 62° C. for 5 hours, wash, and dry under reduced pressure at 80° C. for 2 hours to obtain modified coconut shell fiber; (5) The preparation method of the sulfuric acid modified rubber comprises the following steps: taking waste tire particles with a diameter of 2 mm to 4 mm and no impurities on the surface, soaking them in a 10% sulfuric acid solution of 3 times the weight of the waste tire particles for 2 hours to modify their surfaces, and drying them to obtain the sulfuric acid modified rubber.

[0047] This embodiment also provides a preparation method of the above-mentioned cement-based thermal insulation material, and the preparation method comprises the following steps: mixing the above-mentioned thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, bagasse fiber, modified coconut shell fiber, gypsum and water reducer to obtain a cement-based thermal insulation material, which is recorded as cement-based thermal insulation material III.

[0048] Comparative Example 1 Comparative Example 1 provides a cement-based thermal insulation material. The raw materials and preparation method of the cement-based thermal insulation material in this comparative example are basically the same as those in Example 3. The only difference is that: in terms of raw materials, sulfuric acid-modified rubber is not added, and the types and amounts of other raw materials are the same as those in Example 3. The obtained product is recorded as cement-based thermal insulation material comparative example I.

[0049] Comparative Example 2 Comparative Example 2 provides a cement-based thermal insulation material. The raw materials and preparation method of the cement-based thermal insulation material in this comparative example are basically the same as those in Example 3, with the only difference being that: in terms of raw materials, "1.5 parts of plant fiber composite" is replaced by "1.5 parts of bagasse fiber", and "sulfuric acid modified rubber" is replaced by an equal amount of "potassium permanganate modified rubber", and the types and amounts of other raw materials are the same as those in Example 3. The obtained product is recorded as cement-based thermal insulation material comparison II.

[0050] The preparation method of potassium permanganate modified rubber is as follows: take waste tire particles with a diameter of 2mm-4mm and no impurities on the surface, add 5wt% potassium permanganate solution with a weight of 3 times that of the waste tire particles, soak for 2h to modify the surface, and dry to obtain the potassium permanganate modified rubber.

[0051] Effect example The cement-based thermal insulation materials prepared in Examples 1 to 3 and Comparative Examples 1-2 were added with water at a water-cement ratio of 0.5 to prepare slurries. The five slurries were grouted, left to stand for 24 hours to demould and subjected to standard curing for 28 days to prepare test blocks, and the performance of different test blocks was further measured.

[0052] The dry density of the sample was tested according to the method recommended by JG158-2019; the compressive strength and flexural strength test methods of cement mortar were tested according to the national standard GB / T 17671-1999 "Test Method for Strength of Cement Mortar" (ISO method), and the compressive strength test was carried out by controlling the loading rate, and the loading rate was 2kN / s. The load sensor records, and when the loading stops, wait for 3s to read; the flexural strength test was carried out by hydraulic loading, and the reading accuracy was 0.1MPa. The thermal conductivity of the sample was tested by YG-DRL02 thermal conductivity measuring instrument, the water absorption was tested according to the method described in GB / T 11970-1997, and the compression shear bond strength was tested according to the method described in JC / T 547-2017. The specific test results are shown in Table 1.

[0053] Table 1

[0054] From the data in Table 1, it can be seen that compared with the test blocks with only plant fiber composites and no sulfuric acid modified rubber, the test blocks with both plant fiber composites and sulfuric acid modified rubber have better mechanical properties and lower thermal conductivity and water absorption resistance. Replacing the "modified coconut shell fiber" in the "plant fiber composite" with an equal amount of "bagasse fiber" will significantly increase the water absorption of the resulting test block, and the increase in water absorption will increase the risk of fiber expansion, degradation or detachment from the cement matrix at the interface, which will have an adverse effect on the mechanical properties and durability of the composite material; at the same time, sulfuric acid modified rubber has a positive effect on improving compressive strength and compression-shear bond strength compared with potassium permanganate rubber.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0056] [Z1] The inventors have sought to improve the stability of the raw material, which is reflected here [Z2] As this patent is based on existing public literature, the inventor is kindly requested to read and consider the raw material ratios and experimental conditions in the examples based on his / her experience in the field, and to determine whether there are any unreasonable aspects or details of the present invention.

Claims

1. A cement-based thermal insulation material, characterized in that: The invention comprises the following components in parts by weight: 70 to 76 parts of thermal insulation and environmentally friendly cement, 19 to 22 parts of polystyrene foam particles, 3 to 6 parts of sulfuric acid modified rubber, 1.5 to 2.5 parts of plant fiber composite, 3 to 5 parts of gypsum and 0.18 to 0.23 parts of water reducing agent; Wherein, the thermal insulation and environmentally friendly cement contains a modified alcoholamine compound; The modified alcoholamine compound is obtained by polymerizing an intermediate obtained by the reaction of pyromellitic anhydride and alcoholamine substances with acrylic acid and methyl allyl alcohol polyoxyethylene ether; The plant fiber composite comprises bagasse fiber and modified coconut shell fiber.

2. The cement-based thermal insulation material according to claim 1, characterized in that: The thermal insulation and environmentally friendly cement also includes limestone, steel slag, diatomaceous earth, vermiculite, gypsum and coal gangue.

3. The cement-based thermal insulation material according to claim 2, characterized in that: The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 70 to 80 parts of limestone, 3 to 6 parts of steel slag, 1 to 3 parts of diatomaceous earth, 2 to 4 parts of vermiculite, 0.8 to 1.6 parts of gypsum, 6 to 10 parts of coal gangue and 0.4 to 0.6 parts of modified alcohol amine compound.

4. The cement-based thermal insulation material according to claim 2 or 3, characterized in that: The preparation method of the thermal insulation and environmentally friendly cement comprises the following steps: S1. Crush limestone and vermiculite separately to obtain corresponding granular materials with a particle size not exceeding 2 cm, and mix them to obtain a granular material mixture; S2, coarsely grinding the granular material mixture, adding the steel slag, diatomaceous earth and the first part of the modified alcoholamine compound, and grinding to obtain cement raw material; S3, drying the cement raw material, firing it at 1300° C. to 1400° C. for 35 min to 45 min, cooling, rolling, breaking it up, adding the remaining modified alcoholamine compound and grinding it to obtain cement clinker; S4. Mixing the cement clinker, gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

5. The cement-based thermal insulation material according to claim 4, characterized in that: In step S2, the weight of the first part of the modified alcoholamine compound accounts for 60% to 70% of the total amount of the modified alcoholamine compound.

6. The cement-based thermal insulation material according to claim 1, characterized in that: The preparation method of the sulfuric acid modified rubber comprises: soaking waste tire particles in 8wt%-10wt% sulfuric acid for 2h-3h to obtain the sulfuric acid modified rubber.

7. The cement-based thermal insulation material according to claim 1, characterized in that: The preparation method of the modified coconut shell fiber comprises: adding water and stearic acid to the coconut shell fiber, and soaking the coconut shell fiber at 60° C. to 65° C. for 4 hours to 6 hours to obtain the modified coconut shell fiber.

8. The cement-based thermal insulation material according to claim 1 or 7, characterized in that: The weight ratio of the bagasse fiber to the modified coconut shell fiber is 1:2-4.

9. The method for preparing the cement-based thermal insulation material according to any one of claims 1 to 8, characterized in that: The preparation method comprises: uniformly mixing the heat-insulating and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, plant fiber composite, gypsum and a water reducing agent to obtain a cement-based heat-insulating material.

10. Use of the cement-based thermal insulation material according to any one of claims 1 to 8 in thermal insulation walls.

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