Thermal insulation lightweight concrete and method for producing the same

Abstract

The application relates to the technical field of building thermal insulation materials, and particularly discloses a thermal insulation lightweight concrete and a preparation method thereof. The thermal insulation lightweight concrete comprises the following components in parts by weight: 340-360 parts of cement, 85-95 parts of fly ash, 20-40 parts of rice husk ash, 250-270 parts of sand, 12-16 parts of EPS particles, 9-12 parts of expanded perlite particles, 5-8 parts of sepiolite fibers, 8-12 parts of an anti-floating agent, 7-9 parts of a water reducing agent and 165-180 parts of water, wherein the anti-floating agent is prepared by mixing corn starch, starch phosphate, polyethylene oxide and sodium lignosulfonate. The application adds the anti-floating agent into the lightweight concrete, so that the structural stability and mechanical properties of the lightweight concrete are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building insulation materials, in particular to a thermal insulation lightweight concrete and a preparation method thereof. BACKGROUND

[0002] With the continuous development of China's construction industry, more and more building construction has integrated the concept of energy saving and environmental protection. The insulation technology plays a crucial role in building energy saving, and the lightweight concrete has a lower thermal conductivity than ordinary concrete, which also makes it an ideal insulation material in the field of building.

[0003] In the prior art, in order to reduce the unit weight of concrete, light aggregate is generally added to realize the lightweight of concrete. EPS (polystyrene foam) particles have the advantages of lightweight and low thermal conductivity, and when they are added to concrete as light aggregate, the lightweight of concrete can be well realized, and lightweight concrete with good thermal insulation performance can be obtained. However, EPS particles are hydrophobic organic materials, which have poor compatibility with inorganic materials such as concrete, and the density of EPS particles is small, which is easy to float during the mixing and molding process. These phenomena can easily lead to uneven dispersion of EPS particles in lightweight concrete, resulting in uneven density of lightweight concrete and reducing the structural stability of lightweight concrete, which has a certain impact on the mechanical properties of lightweight concrete.

[0004] Therefore, in order to further enhance the mechanical properties of lightweight concrete, it is necessary to further improve the dispersity of EPS particles in lightweight concrete. SUMMARY

[0005] In order to further improve the dispersity of EPS particles in lightweight concrete, the present application provides a thermal insulation lightweight concrete and a preparation method thereof. By adding an anti-floating agent to the lightweight concrete, the present application effectively inhibits the aggregation and floating of EPS particles in the concrete, effectively improves the dispersity of EPS particles in the concrete, ensures the uniformity and quality of the lightweight concrete, and thus improves the structural stability and mechanical properties of the lightweight concrete.

[0006] In a first aspect, the present application provides a thermal insulation lightweight concrete using the following technical scheme:

[0007] A thermal insulation lightweight concrete comprises the following components by weight: 340-360 parts of cement, 85-95 parts of fly ash, 20-40 parts of rice husk ash, 250-270 parts of sand, 12-16 parts of EPS particles, 9-12 parts of expanded perlite particles, 5-8 parts of sepiolite fibers, 8-12 parts of an anti-floating agent, 7-9 parts of a water reducing agent, and 165-180 parts of water, wherein the anti-floating agent is prepared by mixing corn starch, starch phosphate, polyethylene oxide and sodium lignosulfonate.

[0008] By the above technical solution, by adding a specific proportion of anti-floating agent, the thermal insulation lightweight concrete of the present application not only maintains good thermal insulation performance, but also significantly improves its structural stability and mechanical properties. The addition of the anti-floating agent not only improves the dispersibility of the EPS particles, but also enhances the compatibility between the EPS particles and the concrete matrix through its unique chemical composition, thereby effectively preventing the agglomeration and floating of the EPS particles. Specifically, the anti-floating agent can form a colloid in water and provide a negative charge, which effectively enhances the interaction between the EPS particles and the concrete, thereby improving the stability of the EPS particles in the concrete, significantly reducing the floating or agglomeration of the EPS particles, promoting the stable dispersion of the EPS particles, and further enhancing the adhesion between the EPS particles and the concrete by the interaction between the hydrophilic groups in the anti-floating agent and the hydrophobic groups on the surface of the EPS particles. The dispersibility of the EPS particles in the concrete is further improved, and the uniform distribution of the EPS particles is promoted, thereby ensuring the uniformity and thermal insulation of the thermal insulation lightweight concrete.

[0009] Meanwhile, the thermal insulation lightweight concrete of the present application also adds sepiolite fibers and rice husk ash, which cooperate with each other and interact with the anti-floating agent to further enhance the bonding strength between the EPS particles, expanded perlite particles and the concrete, reduce the floating of lightweight aggregate, further improve the structural stability and mechanical properties of the concrete, and also improve the flame retardant performance of the concrete. Specifically, the rice husk ash can effectively fill the micropores and voids between the EPS particles, expanded perlite particles and the concrete matrix through the pozzolanic reaction, and cooperate with the anti-floating agent to optimize the interface transition period in the concrete from the micro level, while the sepiolite fibers penetrate the interior of the concrete through toughening and bridging effect, and the gel formed by the rice husk ash and the anti-floating agent is more uniformly distributed around the fibers, which synergistically form a more solid interface bonding, thereby enhancing the overall structure of the concrete.

[0010] Further, the mixing mass ratio of the corn starch, starch phosphate, polyethylene oxide and sodium lignosulfonate is 1:(0.5-0.7):(0.3-0.5):(0.1-0.2).

[0011] Further, the mixing mass ratio of the corn starch, starch phosphate, polyethylene oxide and sodium lignosulfonate is 1:0.6:0.4:0.15.

[0012] Further, the preparation method of the anti-floating agent comprises: adding corn starch into 10 times the volume of water at 50-60℃, stirring uniformly, then sequentially adding starch phosphate, polyethylene oxide and sodium lignosulfonate, continuing to stir for 10-20min, and drying to obtain the anti-floating agent.

[0013] Through the above technical scheme, through such a preparation method, a stable performance anti-floating agent can be obtained, which can effectively play its role in concrete, inhibit the floating or agglomeration phenomenon of EPS particles and other lightweight aggregates, and thus ensure the uniformity and stability of the thermal insulation lightweight concrete.

[0014] Further, the mass ratio of the EPS particles and the expanded perlite particles is 15:10.

[0015] Through the above technical scheme, by selecting a specific ratio of EPS particles and expanded perlite particles, the lightweight concrete can maintain good thermal insulation performance while further improving its structural stability and mechanical properties. The uniform distribution of EPS particles and expanded perlite particles in the concrete helps to form a more uniform pore structure, thereby improving the thermal insulation performance of the concrete. By further controlling the ratio of EPS particles and expanded perlite particles, the density and strength of the concrete can be further optimized, so that the lightweight concrete of the present application not only meets the thermal insulation requirements, but also has sufficient structural strength.

[0016] Further, the fineness modulus of the sand is 2.6-2.8.

[0017] Through the above technical scheme, by optimizing the particle size distribution of the EPS particles and the expanded perlite particles, and the fineness modulus of the sand, and by optimizing the mass ratio of the EPS particles and the expanded perlite particles, the uniformity of the concrete is further ensured, and the aggregate framework of the concrete is further optimized, the structural stability of the concrete is improved, and the mechanical strength of the concrete is further enhanced.

[0018] Further, the preparation method of the rice husk ash comprises: calcining rice husk at 450-500℃ for 30-45min, and then grinding for 30-35min to obtain rice husk ash.

[0019] Further, the rice husk ash is a modified rice husk ash, and the preparation method of the modified rice husk ash comprises the following steps:

[0020] Step s1: completely immerse the rice husk ash in a 2mol / L sodium hydroxide solution, then treat at a temperature of 90-100℃ for 1-1.2h, and take out and dry;

[0021] Step s2: disperse 100 parts of the dried rice husk ash in 5-10 times the volume of water at 120-130℃, add 8-12 parts of ammonium dihydrogen phosphate and 2-3 parts of polyethyleneimine, mix and stir for 1-2h, then add 10-15 parts of urea and continue stirring for 1-2h, filter, and dry at 100-120℃ to obtain the modified rice husk ash.

[0022] By the technical scheme, the rice husk ash is modified by using sodium hydroxide, ammonium dihydrogen phosphate, polyethyleneimine and urea, and the rice husk ash is modified from multiple aspects such as surface activation and active site optimization, flame retardancy optimization, interface bonding and microstructure optimization, so that the activity, dispersibility and flame retardancy of the rice husk ash are further improved, and the combination ability of the rice husk ash and the concrete is enhanced, thereby further enhancing the structural stability and mechanical properties of the concrete. Specifically, by alkali activation of NaOH, the surface impurities of the rice husk ash are removed, the surface reaction active sites of the rice husk ash are increased, and the surface reaction activity of the rice husk ash is improved, so that the subsequent ammonium dihydrogen phosphate, polyethyleneimine and urea can be more effectively adsorbed on the active sites to form effective combination. The ammonium dihydrogen phosphate, polyethyleneimine and urea jointly act on the rice husk ash, so that the interface bonding force and the flame retardancy of the rice husk ash are synergistically improved, thereby making the concrete have better flame retardancy and mechanical properties.

[0023] Further, the mass ratio of the rice husk ash and the sepiolite fiber is 30:7.

[0024] By the technical scheme, because the rice husk ash has good flame retardant performance, a dense coke layer can be formed under high temperature conditions, and the rice husk ash plays a role of heat insulation and oxygen isolation. The sepiolite fiber itself also has certain heat resistance and chemical stability, and can maintain structural integrity in a high-temperature environment. After the two are combined, not only the stability of the concrete is improved, but also the flame retardant performance of the concrete is unexpectedly improved.

[0025] In a second aspect, the application provides a preparation method of the thermal insulation lightweight concrete, which adopts the following technical scheme:

[0026] The preparation method of the thermal insulation lightweight concrete comprises the following steps:

[0027] Step 1: Take 20% to 25% of the formula amount of water, add the anti-floating agent and stir until uniform, then add the EPS particles and the expanded perlite particles and continue to stir until uniform, and then add the rice husk ash and the sepiolite fiber and stir until uniform to obtain material 1; take the cement, the fly ash and the sand and stir until uniform to obtain material 2; take the remaining water, add the water reducing agent and stir until uniform to obtain material 3;

[0028] Step 2: First, mix and stir the material 2 and the material 3 until uniform, then add the material 1 and continue to stir until uniform to obtain the thermal insulation lightweight concrete.

[0029] By the preparation method, the components can be uniformly mixed, and in particular, the EPS particles and the expanded perlite particles can be well dispersed in the concrete, so that the lightweight concrete with good thermal insulation performance and mechanical properties can be prepared. The preparation method of the application is convenient to operate, suitable for industrial production and has good application prospect.

[0030] In summary, the present application includes at least one of the following beneficial technical effects:

[0031] 1. The use of anti-float agent promotes the uniform distribution of EPS particles and expanded perlite particles, forming a more uniform pore structure, effectively improving the thermal insulation performance of the concrete.

[0032] 2. By optimizing the ratio of EPS particles and expanded perlite particles, and the fineness modulus of sand, the aggregate framework of the concrete is optimized, thereby improving the structural stability and mechanical strength of the concrete.

[0033] 3. By modifying rice husk ash, the flame retardant performance of the concrete is improved, and by combining the use of rice husk ash and sepiolite fibers, not only the stability of the concrete is further improved, but also the flame retardant performance of the concrete is further enhanced. DETAILED DESCRIPTION

[0034] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in conjunction with specific examples.

[0035] Preparation Example 1

[0036] A preparation method of an anti-float agent, comprising: adding 1 kg of corn starch into 10 times the volume of water at 55℃, stirring uniformly, then adding 0.6 kg of starch phosphate, 0.4 kg of polyethylene oxide and 0.15 kg of sodium lignosulfonate in turn, continuing to stir for 15 min, drying to obtain the anti-float agent.

[0037] Among them, the corn starch is a pre-gelatinized corn starch purchased from Shandong Xuguang Chemical Co., Ltd.; the starch phosphate is a phosphatized distarch phosphate purchased from Shandong Aicai Biological Technology Co., Ltd.; the polyethylene oxide is a U.S. Dow polyethylene oxide PEO purchased from Shanghai Yudaobao Chemical Co., Ltd.; and the sodium lignosulfonate is purchased from Jinan Runyue Chemical Co., Ltd.

[0038] Preparation Example 2

[0039] A preparation method of an anti-float agent, different from Preparation Example 1, comprising: adding 1 kg of corn starch into 10 times the volume of water at 50℃, stirring uniformly, then adding 0.5 kg of starch phosphate, 0.5 kg of polyethylene oxide and 0.1 kg of sodium lignosulfonate in turn, continuing to stir for 20 min, drying to obtain the anti-float agent.

[0040] Preparation Example 3

[0041] A preparation method of an anti-floating agent, different from the preparation example 1, comprises: adding 1 kg of corn starch into 10 times volume of water at 60℃, stirring uniformly, then adding 0.7 kg of starch phosphate, 0.3 kg of polyethylene oxide and 0.2 kg of sodium lignosulfonate in turn, continuing to stir for 10 min, drying, and obtaining the anti-floating agent.

[0042] Preparation example 4

[0043] A preparation method of an anti-floating agent, different from the preparation example 1, is that starch phosphate is replaced by acetate starch in equal amount, and the remaining steps are the same.

[0044] The acetate starch is acetate starch E1420 purchased from Guangdong Mingcheng Biological Technology Co., Ltd.

[0045] Preparation example 5

[0046] A preparation method of an anti-floating agent, different from the preparation example 1, is that polyethylene oxide is replaced by sodium polyacrylate in equal amount, and the remaining steps are the same.

[0047] The sodium polyacrylate is sodium polyacrylate purchased from Guangdong Mingcheng Biological Technology Co., Ltd.

[0048] Preparation example 6

[0049] A preparation method of an anti-floating agent, different from the preparation example 1, is that sodium lignosulfonate is replaced by sodium carboxymethyl cellulose in equal amount, and the remaining steps are the same.

[0050] The sodium carboxymethyl cellulose is sodium carboxymethyl cellulose purchased from Guangdong Mingcheng Biological Technology Co., Ltd.

[0051] Preparation example 7

[0052] A preparation method of rice husk ash, comprising: taking dry rice husk, calcining at 450℃ for 15 min, then heating to 500℃ within 10 min, continuing to calcine for 15 min, then grinding the calcined material for 35 min, and passing through a 200 mesh sieve to obtain rice husk ash.

[0053] Preparation example 8

[0054] A preparation method of modified rice husk ash, comprising the following steps:

[0055] Step s1: taking the rice husk ash obtained in preparation example 7, completely immersing it in a 2 mol / L sodium hydroxide solution, then treating at a temperature of 90℃ for 1h, and taking out and drying.

[0056] Step s2: 10 kg of dried rice husk ash was dispersed in 8 times the volume of water at 120℃, 1.2 kg of ammonium dihydrogen phosphate and 0.2 kg of polyethyleneimine were added, mixed and stirred for 2 h, then 1 kg of urea was added and stirred for 2 h, filtered, and dried at 100℃ to obtain modified rice husk ash.

[0057] The ammonium dihydrogen phosphate was purchased from Guangdong Mingcheng Biological Technology Co., Ltd., the polyethyleneimine was purchased from Maoming Xiongda Chemical Co., Ltd., the average molecular weight was 1800, and the urea was purchased from Foshan Guangzheng Chemical Co., Ltd., the item number was GZ20200226.

[0058] Preparation Example 9

[0059] A method for preparing modified rice husk ash, different from preparation example 8, comprising the following steps:

[0060] Step s1: The rice husk ash obtained in preparation example 7 was completely immersed in a 2 mol / L sodium hydroxide solution, then treated at a temperature of 98℃ for 1.2 h, and then taken out and dried.

[0061] Step s2: 10 kg of dried rice husk ash was dispersed in 5 times the volume of water at 130℃, 0.8 kg of ammonium dihydrogen phosphate and 0.3 kg of polyethyleneimine were added, mixed and stirred for 1.5 h, then 1.5 kg of urea was added and stirred for 1.5 h, filtered, and dried at 105℃ to obtain modified rice husk ash.

[0062] Preparation Example 10

[0063] A method for preparing modified rice husk ash, different from preparation example 8, wherein ammonium dihydrogen phosphate is replaced by an equal amount of ammonium polyphosphate, and the remaining steps are the same.

[0064] Preparation Example 11

[0065] A method for preparing modified rice husk ash, different from preparation example 8, wherein polyethyleneimine is replaced by an equal amount of sodium polyacrylate, and the remaining steps are the same.

[0066] The ammonium polyphosphate was purchased from Guangzhou Shanghe Chemical Technology Co., Ltd.

[0067] Preparation Example 12

[0068] A method for preparing modified rice husk ash, different from preparation example 8, wherein urea is replaced by an equal amount of tetramethylammonium chloride phosphate, and the remaining steps are the same.

[0069] The tetramethylammonium chloride phosphate was purchased from Wuhan Chengtian Fine Chemical Co., Ltd.

[0070] Example 1

[0071] A thermal insulation lightweight concrete, comprising 3.5 kg of cement, 0.9 kg of fly ash, 0.3 kg of rice husk ash, 2.6 kg of sand, 0.15 kg of EPS particles, 0.1 kg of expanded perlite particles, 0.07 kg of sepiolite fiber, 0.1 kg of anti-floating agent, 0.08 kg of water reducing agent, and 1.72 kg of water.

[0072] The cement is P·O 42.5 from Hunan Xindingli New Material Technology Co., Ltd.

[0073] The fly ash is first-grade fly ash with a particle size of 200 mesh.

[0074] The rice husk ash is prepared by Preparation Example 7.

[0075] The sand is river sand with a fineness modulus of 2.73.

[0076] The EPS particles are 5-8 mm lightweight polyphenyl round particles purchased from Henan Jiufeng Water Treatment Co., Ltd.

[0077] The expanded perlite particles are 2-4 mm expanded perlite particles purchased from Shenyang Jiachuang Kai Insulation Material Co., Ltd.

[0078] The sepiolite fiber is purchased from Shijiazhuang Mayue Building Material Co., Ltd. with a specification of 1-4 mm.

[0079] The anti-floating agent is prepared by Preparation Example 1.

[0080] The water reducing agent is a polycarboxylic acid water reducing agent from Wuhan Runxingyuan Technology Co., Ltd.

[0081] The preparation method of the thermal insulation lightweight concrete comprises the following steps:

[0082] Step 1: Take 24% of the formula amount of water, add the anti-floating agent obtained in Preparation Example 1 and stir uniformly, then add the EPS particles and expanded perlite particles and continue to stir uniformly, and then add the rice husk ash and sepiolite fiber and stir uniformly to obtain material 1.

[0083] Step 2: Stir the cement, fly ash, and sand uniformly to obtain material 2.

[0084] Step 3: Take the remaining water, add the water reducing agent and stir uniformly to obtain material 3.

[0085] Step 4: First, mix and stir material 2 and material 3 uniformly, then add material 1, and continue to stir uniformly to obtain the thermal insulation lightweight concrete.

[0086] Example 2

[0087] A thermal insulation lightweight concrete, different from Example 1, comprises 3.4 kg cement, 0.85 kg fly ash, 0.2 kg rice husk ash, 2.5 kg sand, 0.12 kg EPS particles, 0.09 kg expanded perlite particles, 0.05 kg sepiolite fiber, 0.08 kg anti-floating agent, 0.07 kg water reducing agent, 1.65 kg water.

[0088] The anti-floating agent is prepared by Preparation Example 2.

[0089] The preparation method of the thermal insulation lightweight concrete comprises the following steps:

[0090] Step 1: Take 20% of the formula amount of water, add the anti-floating agent obtained in Preparation Example 1 and stir until uniform, then add the EPS particles and expanded perlite particles and continue to stir until uniform, and then add the rice husk ash and sepiolite fiber and stir until uniform to obtain material 1.

[0091] Step 2: Take the cement, fly ash and sand and stir until uniform to obtain material 2.

[0092] Step 3: Take the remaining water, add the water reducing agent and stir until uniform to obtain material 3.

[0093] Step 4: First, mix and stir material 2 and material 3 until uniform, then add material 1 and continue to stir until uniform to obtain the thermal insulation lightweight concrete.

[0094] Example 3

[0095] A thermal insulation lightweight concrete, different from Example 1, comprises 3.6 kg cement, 0.95 kg fly ash, 0.4 kg rice husk ash, 2.7 kg sand, 0.16 kg EPS particles, 0.12 kg expanded perlite particles, 0.08 kg sepiolite fiber, 0.12 kg anti-floating agent, 0.09 kg water reducing agent, 1.8 kg water.

[0096] The anti-floating agent is prepared by Preparation Example 3.

[0097] The preparation method of the thermal insulation lightweight concrete comprises the following steps:

[0098] Step 1: Take 25% of the formula amount of water, add the anti-floating agent obtained in Preparation Example 1 and stir until uniform, then add the EPS particles and expanded perlite particles and continue to stir until uniform, and then add the rice husk ash and sepiolite fiber and stir until uniform to obtain material 1.

[0099] Step 2: Take the cement, fly ash and sand and stir until uniform to obtain material 2.

[0100] Step 3: Take the remaining water, add the water reducing agent and stir until uniform to obtain material 3.

[0101] Step 4: Mix and stir material 2 and material 3 first, then add material 1, continue to stir until uniform, to obtain the thermal insulation lightweight concrete.

[0102] Example 4

[0103] A thermal insulation lightweight concrete, different from Example 1, is that the rice husk ash is prepared from Preparation Example 8.

[0104] Example 5

[0105] A thermal insulation lightweight concrete, different from Example 1, is that the rice husk ash is prepared from Preparation Example 9.

[0106] Example 6

[0107] A thermal insulation lightweight concrete, different from Example 1, is that the rice husk ash is prepared from Preparation Example 10.

[0108] Example 7

[0109] A thermal insulation lightweight concrete, different from Example 1, is that the rice husk ash is prepared from Preparation Example 11.

[0110] Example 8

[0111] A thermal insulation lightweight concrete, different from Example 1, is that the rice husk ash is prepared from Preparation Example 12.

[0112] Comparative Example 1

[0113] A thermal insulation lightweight concrete, different from Example 1, is that the anti-floating agent is prepared from Preparation Example 4.

[0114] Comparative Example 2

[0115] A thermal insulation lightweight concrete, different from Example 1, is that the anti-floating agent is prepared from Preparation Example 5.

[0116] Comparative Example 3

[0117] A thermal insulation lightweight concrete, different from Example 1, is that the anti-floating agent is prepared from Preparation Example 6.

[0118] Comparative Example 4

[0119] A thermal insulation lightweight concrete, different from Example 1, is that the sepiolite fiber is replaced with an equal amount of glass fiber.

[0120] The glass fiber is a short-cut glass fiber purchased from the Lingshou County Yaoyang Mineral Product Processing Factory, with a specification of 1-4 mm.

[0121] Performance test

[0122] Mechanical properties: The thermal insulation lightweight concrete slurries of Examples 1-8 and Comparative Examples 1-4 were prepared respectively, and were prepared into 150mm*150mm*150mm standard cubic test pieces for 28d compressive strength test, and were prepared into 150mm*150mm*550mm standard prismatic test pieces for 28d flexural strength test, and the experimental equipment was an electronic universal testing machine, and the test adopted a three-point bending loading load mode.

[0123] Combustion heat value: According to GB / T 14402-2007, an appropriate amount of the thermal insulation lightweight concrete blocks of Examples 1-8 and Comparative Examples 1-4 were taken, were ground into powder, and the powder and benzoic acid were put into an oxygen bomb for testing according to a mass ratio of 1:2, and the experimental equipment was an oxygen bomb calorimeter with constant heat capacity.

[0124] Non-combustibility test: According to GB / T 5464-2010, the thermal insulation lightweight concrete slurries of Examples 1-8 and Comparative Examples 1-4 were prepared into cylinders with a height of 50mm and a diameter of 45mm, were weighed before test M1 after curing for 28d, were then put into a thermocouple heating combustion furnace at 750℃ for testing, after the fire lasted for 5s, the timing was started, the fire starting time t1 was recorded, after the flame was extinguished, the continuous combustion time t2 of the concrete block was recorded, the test was stopped after the temperature in the furnace reached equilibrium again, the temperature rise T in the furnace was recorded, finally the concrete block after the test was taken out, was weighed after test M2, and the mass loss rate (%) was calculated, mass loss rate (%) = (M1-M2) / M1*100%.

[0125] The above test results are shown in Table 1.

[0126] Table 1:

[0127]

[0128] From Table 1, by comparing the test data of the examples and the comparative examples, it can be seen that the thermal insulation lightweight concrete of Examples 1-8 performs well in terms of 28-day compressive strength and flexural strength, and the thermal insulation lightweight concrete of Examples 4-8 performs well in terms of combustion heat value and mass loss rate, which shows that the thermal insulation lightweight concrete of the application has good mechanical properties, and further adding modified rice husk ash in the thermal insulation lightweight concrete can further improve the flame retardant performance.

[0129] Specifically combined with Example 1 and Comparative Examples 1-3, we can see that the thermal insulation lightweight concrete of Example 1 performs well in terms of 28-day compressive strength and flexural strength, which indicates that the use of the anti-floating agent provided in the application in the thermal insulation lightweight concrete can effectively inhibit the aggregation and floating of the EPS particles in the concrete, effectively improve the dispersibility of the EPS particles in the concrete, ensure the uniformity and quality of the lightweight concrete, and thus effectively improve the mechanical properties of the thermal insulation lightweight concrete.

[0130] Specifically combined with Example 1 and Comparative Example 4, we can see that the thermal insulation lightweight concrete of Example 1 performs well in terms of 28-day compressive strength and flexural strength, which indicates that the use of sepiolite fibers in the thermal insulation lightweight concrete can effectively improve the mechanical properties of the concrete, which further indicates that there is a certain synergistic effect between sepiolite fibers and rice husk ash in improving the mechanical properties of the thermal insulation lightweight concrete, and sepiolite fibers have unique advantages in this respect.

[0131] Specifically combined with Example 1 and Examples 4-8, we can see that the modified rice husk ash used in Examples 4-8 further enhances the flame-retardant effect of the material. Specifically combined with Example 4 and Examples 6-8, we can see that the flame-retardant effect of Example 4 performs well, which indicates that ammonium dihydrogen phosphate, urea and polyethyleneimine can better cooperate to improve the flame-retardant effect of the thermal insulation lightweight concrete. The applicant believes that this is because the cooperation of ammonium dihydrogen phosphate, urea and polyethyleneimine can promote the formation of a dense coke layer, making the formed coke layer more dense and stable, thus showing good flame-retardant effect.

[0132] This specific embodiment is merely an explanation of the application and is not a limitation of the application. Those skilled in the art can make modifications to this embodiment without creative contribution after reading this specification, but as long as the modifications are within the scope of the claims of the application, they are protected by the Patent Law.

Claims

1. An insulating lightweight concrete, characterized in that, The composition comprises the following components in parts by weight: 340-360 parts of cement, 85-95 parts of fly ash, 20-40 parts of rice husk ash, 250-270 parts of sand, 12-16 parts of EPS particles, 9-12 parts of expanded perlite particles, 5-8 parts of sepiolite fibers, 8-12 parts of anti-floating agent, 7-9 parts of water reducing agent, and 165-180 parts of water, wherein the anti-floating agent is prepared by mixing corn starch, starch phosphate, polyethylene oxide and sodium lignosulfonate; The mixing mass ratio of the corn starch, the starch phosphate, the polyethylene oxide and the sodium lignosulfonate is 1:(0.5-0.7):(0.3-0.5):(0.1-0.2); The preparation method of the anti-floating agent comprises the following steps: adding corn starch into 10 times the volume of water at 50-60°C, stirring uniformly, then sequentially adding starch phosphate, polyethylene oxide and sodium lignosulfonate, continuing to stir for 10-20 min, and drying to obtain the anti-floating agent; The rice husk ash is modified rice husk ash, and the preparation method of the modified rice husk ash comprises the following steps: Step s1: completely immerse the rice husk ash in a 2 mol / L sodium hydroxide solution, and then treat at a temperature of 90-100°C for 1-1.2 h, and take out for drying; Step s2: disperse 100 parts of the dried rice husk ash in 5-10 times the volume of water again at 120-130°C, add 8-12 parts of ammonium dihydrogen phosphate and 2-3 parts of polyethyleneimine, mix and stir for 1-2 h, then add 10-15 parts of urea and continue to stir for 1-2 h, filter, and dry at 100-120°C to obtain the modified rice husk ash.

2. A thermal lightweight concrete according to claim 1, characterized in that The mixing mass ratio of the corn starch, the starch phosphate, the polyethylene oxide and the sodium lignosulfonate is 1:0.6:0.4:0.

15.

3. A thermal insulation lightweight concrete according to claim 1, characterized in that, The EPS particles are continuous grade particles with a particle size distribution of 5-8 mm, and the expanded perlite particles are continuous grade particles with a particle size distribution of 2-4 mm.

4. A thermal lightweight concrete according to claim 3, characterised in that The mass ratio of the EPS particles and the expanded perlite particles is 15:

10.

5. A thermal lightweight concrete according to claim 1, characterized in that The preparation method of the rice husk ash comprises calcining rice husk at 450-500°C for 30-45 min, and then grinding for 30-35 min to obtain the rice husk ash.

6. A thermal insulation lightweight concrete according to any one of claims 1 to 5, characterised in that The mass ratio of the rice husk ash and the sepiolite fibers is 30:

7.

7. A method for the production of insulating lightweight concrete according to any one of claims 1 to 6, characterised in that The method comprises the following steps: Step 1: take 20%-25% of the formula amount of water, add the anti-floating agent and stir uniformly, then add the EPS particles and the expanded perlite particles and continue to stir uniformly, then add the rice husk ash and the sepiolite fibers and stir uniformly to obtain material 1; take the cement, the fly ash and the sand and stir uniformly to obtain material 2; take the remaining water, add the water reducing agent and stir uniformly to obtain material 3; Step 2: first mix and stir uniformly the material 2 and the material 3, then add the material 1, and continue to stir uniformly to obtain the thermal insulation lightweight concrete.

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