Low-activity rubber material self-compacting concrete as well as preparation method and application thereof

Abstract

The invention provides low-activity rubber material self-compacting concrete and a preparation method and application thereof, and the preparation method comprises the following steps: S1, preparing a surface modifier, and spraying the surface modifier on the surface of stone to obtain modified stone for later use; s2, preparing a dispersing agent mother solution, and mixing the dispersing agent mother solution with a water reducing agent to obtain the modified water reducing agent for later use; and S3, weighing cement, mineral powder, fly ash, stone powder, machine-made sand, the modified stones prepared in the S1, the modified water reducing agent prepared in the S2 and water according to the required proportion, uniformly mixing, and stirring for 2-5 minutes to obtain the low-activity rubber material self-compacting concrete. The obtained low-activity rubber material self-compacting concrete is relatively low in cost, overcomes the working performance problems of poor wrapping property, poor flowability and the like of the self-compacting concrete, has good environmental and economic benefits, is suitable for large-scale popularization and industrial production, and has positive significance in promoting sustainable development of the building industry.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular to a low-activity adhesive self-compacting concrete and a preparation method and application thereof. Background Art

[0002] Self-compacting concrete (SCC) refers to concrete that can flow and compact under its own gravity, can completely fill the formwork even in the presence of dense steel bars, has good homogeneity, and does not require additional vibration. In the field of concrete technology, self-compacting concrete has been widely used due to its good filling properties, self-compactness and high construction efficiency. With the continuous development of my country's construction industry, traditional concrete cannot meet the requirements of construction projects or parts with complex structures, dense steel bars and special-shaped structures, which has led to a surge in demand for self-compacting concrete. Traditional self-compacting concrete is usually prepared from raw materials such as cement, fly ash, mineral powder, sand, gravel, water reducer and water. However, these traditional formulas often require a high binder-to-material ratio and active powder. For example, Chinese patent CN111187040B "A self-compacting concrete with machine-made sand and its preparation method" uses 300-350 parts of cement, 60-90 parts of fly ash, 100-130 parts of mineral powder and other raw materials to prepare self-compacting concrete; Chinese patent CN115057667B "A self-compacting concrete and its production process" uses 315-325 parts of cement, 75-85 parts of mineral powder, 173-178 parts of water, 50-70 parts of modified fly ash and other raw materials to produce self-compacting concrete. The active cementitious material is too high and the material cost is relatively expensive.

[0003] The Chinese patent CN115650673A "A self-compacting concrete with high stone powder content and low carbon content and preparation method" discloses a self-compacting concrete with high stone powder content, which uses stone powder to produce surplus slurry to reduce the amount of cementitious materials in the self-compacting concrete, thereby reducing carbon emissions and reducing the cost of self-compacting concrete. However, stone powder itself is an inert material with a small specific surface area and poor dispersibility. It does not participate in the reaction in the concrete system, which reduces the fluidity and working performance of the self-compacting concrete, and the strength still needs to be further improved.

[0004] Therefore, it is of great significance to provide a self-compacting concrete with low-activity adhesive which can reduce the amount of cementitious materials in the self-compacting concrete, improve the fluidity and workability of the concrete, and have excellent strength, as well as a preparation method and application thereof. Summary of the invention

[0005] In view of the fact that the existing low-cost self-compacting concrete has poor stone powder dispersibility, which reduces the fluidity and working performance of the self-compacting concrete, and the strength still needs to be further improved, the present invention provides a low-activity adhesive self-compacting concrete and a preparation method and application thereof. The effect of dispersing stone powder is achieved by introducing a modified water-reducing agent, thereby ensuring that the self-compacting concrete has good fluidity and working performance. At the same time, in order to ensure the encapsulation and homogeneity of the self-compacting concrete, the present invention performs surface modification on the stones, solves the problem of poor encapsulation of the low-activity adhesive self-compacting concrete, and the obtained low-activity adhesive self-compacting concrete has low cost, overcomes the working performance problems of the self-compacting concrete such as poor encapsulation and poor fluidity, has good environmental and economic benefits, is suitable for large-scale promotion and industrialized production, and has positive significance for promoting the sustainable development of the construction industry.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0008] S1. N, N-dimethylacrylamide, hydroxyethyl acrylate, acrylamide, 3-(methacryloyloxy)propyltrimethoxysilane and N, N'-methylenebisacrylamide were mixed to obtain liquid B1; thioglycolic acid and L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50wt.% liquid B1 and 50wt.% liquid B2 were mixed, 30% concentration of hydrogen peroxide was added, stirring was continued, and the remaining 50wt.% liquid B1 and 50wt.% B2 were added dropwise for 80-100min, kept warm for 1h, diluted with water to obtain a surface modifier, and the surface modifier was sprayed on the surface of the stone to obtain the modified stone for standby use;

[0009] S2. Dissolve methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2200-2600 in water, add 30% concentration of hydrogen peroxide, and keep warm at 45-55°C to obtain a reaction base liquid; dissolve 2-acrylamide-2-methylpropanesulfonic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and acrylic acid in water, stir evenly, and obtain a drop liquid F1; dissolve thioglycolic acid and vitamin C in water, stir evenly, and obtain a drop liquid F2; drop liquids F1 and F2 are respectively added dropwise to the reaction base liquid, and the dropping time is 160-200min and 200-220min, respectively, and the reaction is continued for 1h, and diluted with water to a mass concentration of 50% to obtain a dispersant mother liquor, and the dispersant mother liquor is mixed with a water reducer to obtain the modified water reducer, and stand-by;

[0010] S3. Cement, mineral powder, fly ash, stone powder, machine-made sand and the modified gravel prepared in S1, the modified water-reducing agent prepared in S2 and water are weighed according to the required proportion, mixed evenly, and stirred for 2-5 minutes to obtain the low-activity adhesive self-compacting concrete.

[0011] Furthermore, the mass ratio of N,N-dimethylacrylamide, hydroxyethyl acrylate, acrylamide, 3-(methacryloyloxy)propyltrimethoxysilane, N,N'-methylenebisacrylamide, thioglycolic acid, L-ascorbic acid and hydrogen peroxide in S1 is (38-42):(55-60):(6-8):(8-10):(0.6-0.9):(1.2-1.6):(1.5-2.0):2.

[0012] Furthermore, the mass ratio of the surface modifier to the stone in S1 is (0.003-0.008):1.

[0013] Furthermore, the mass ratio of methyl allyl alcohol polyoxyethylene ether, hydrogen peroxide, 2-acrylamide-2-methylpropane sulfonic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate, acrylic acid, thioglycolic acid and vitamin C in S2 is (280-310):(3-5):(67-73):(10.5-23.1):(24-26):(1.0-1.4):(0.8-1.0).

[0014] Furthermore, the mass ratio of the dispersant mother solution and the water reducing agent in S2 is (0.01-0.04):1.

[0015] Furthermore, the components of S3 include, by weight, 250-300 parts of cement, 30-50 parts of mineral powder, 50-80 parts of fly ash, 80-120 parts of stone powder, 700-820 parts of machine-made sand, 850-950 parts of modified gravel, 7-13 parts of modified water-reducing agent and 155-170 parts of water.

[0016] Furthermore, the fly ash is Class F II and / or Class F I; the parent rock of the stone powder is one or more of granite, limestone or cobblestone; the fineness modulus of the machine-made sand is 2.5-3.6; the stone powder is 100-270 mesh; and the particle size of the gravel is 5-25mm.

[0017] Furthermore, the fineness modulus of the machine-made sand is 2.6-3.4; and the stone powder is 120-200 mesh.

[0018] Another object of the present invention is to provide a low-activity adhesive self-compacting concrete.

[0019] A low-activity adhesive self-compacting concrete is prepared according to any one of the above-mentioned methods for preparing low-activity adhesive self-compacting concrete.

[0020] Another object of the present invention is to provide an application of low-activity adhesive self-compacting concrete.

[0021] The invention discloses a low-activity adhesive self-compacting concrete, which is used for preparing concrete.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] The low-activity adhesive self-compacting concrete provided by the present invention uses cheap inert stone powder to replace the active adhesive, which reduces the amount of active adhesive used in the self-compacting concrete and effectively reduces the material cost. 2 / kg or more, there are larger active sites on the surface of the particles during the grinding process, and the active sites on the surface are more abundant after the hydration reaction to generate calcium sulfonate, hydrated calcium silicate and other substances, these active sites provide adsorption sites for the carboxylate radicals of ordinary water-reducing agents; but the stone powder with granite, limestone or cobblestone as the parent rock has a small specific surface area, and is an inert material itself, and does not participate in the reaction in the concrete system, so the conventional water reducer cannot play a dispersing role. In order to overcome the problem that the traditional water reducer has a poor effect in dispersing stone powder, the present invention introduces a dispersant mother liquor with a high proportion and strong adsorption of sulfonate and phosphate groups in the water reducer, which can be effectively adsorbed on the surface of the inert stone powder particles to achieve the effect of dispersing stone powder, ensuring that the self-compacting concrete has good fluidity and working performance. At the same time, in order to ensure the encapsulation and homogeneity of the self-compacting concrete, the present invention performs surface modification on the stone, and the modifier molecules have a large number of inorganic material-philic silanols and hydrophilic amide groups. When the modifier comes into contact with the stone, the silicon hydroxyl group can quickly bond with the substances on the surface of the stone in a short time, and the modifier molecules are anchored on the surface of the stone. When the stone is mixed into the concrete, the modifier not only gives the stone surface better viscosity, but also can be integrated into the cement paste more quickly. In addition, the hydrophilic end of the modifier is well compatible with the concrete paste, which improves the stone's grip on the paste, making the connection between the stone and the paste tighter, solving the problem of stone not hanging on the paste, and solving the problem of poor encapsulation of low-activity adhesive self-compacting concrete. The resulting low-activity adhesive self-compacting concrete has a low cost and overcomes the working performance problems of poor encapsulation and poor fluidity of self-compacting concrete. It has good environmental and economic benefits, is suitable for large-scale promotion and industrialized production, and has positive significance for promoting the sustainable development of the construction industry. DETAILED DESCRIPTION

[0024] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention is further described by the following examples. Obviously, the following examples are only part of the embodiments of the present invention, rather than all the embodiments; it should be understood that the embodiments of the present invention are only used to illustrate the technical effects of the present invention, rather than to limit the scope of protection of the present invention.

[0025] The raw materials in the examples can all be obtained commercially; unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0026] Example 1

[0027] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0028] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.8wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0029] S2. 280.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 5.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 73.0kg 2-acrylamide-2-methylpropanesulfonic acid, 10.5kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 24.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.0kg thioglycolic acid and 0.8kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, the addition times were 180min and 210min, respectively, and the reaction was continued for 1h, 198.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 4wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0030] S3. According to the required proportion, 250kg of cement, 50kg of mineral powder, 80kg of Class F Grade I fly ash, 120kg of 200-mesh granite powder, 820kg of machine-made sand with a fineness modulus of 3.4, 950kg of modified gravel prepared by S1, 13kg of modified water-reducing agent prepared by S2 and 170kg of water were weighed, placed in a mixer and mixed evenly, stirred for 2 minutes, and the low-activity adhesive self-compacting concrete was obtained.

[0031] Example 2

[0032] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0033] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.8wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0034] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, the dropping times were 180min and 210min, respectively, and the reaction was continued for 1h, 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0035] S3. According to the required proportion, 250kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 100kg of 120-mesh limestone powder, 820kg of machine-made sand with a fineness modulus of 2.6, 950kg of modified gravel prepared by S1, 13kg of modified water-reducing agent prepared by S2 and 170kg of water were weighed, placed in a mixer and mixed evenly, and stirred for 2 minutes to obtain the low-activity adhesive self-compacting concrete.

[0036] Example 3

[0037] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0038] S1. 42.0 kg N, N-dimethylacrylamide, 55.0 kg hydroxyethyl acrylate, 6.0 kg acrylamide, 10.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.6 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.2 kg thioglycolic acid and 2.0 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 251kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 930kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0039] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, the dropping times were 180min and 210min, respectively, and the reaction was continued for 1h, 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0040] S3. According to the required proportion, 300kg of cement, 50kg of mineral powder, 50kg of Class F II fly ash, 80kg of 120-mesh pebble powder, 800kg of machine-made sand with a fineness modulus of 2.8, 930kg of modified gravel prepared by S1, 7kg of modified water-reducing agent prepared by S2 and 170kg of water were weighed, placed in a mixer and mixed evenly, stirred for 2 minutes, and the low-activity adhesive self-compacting concrete was obtained.

[0041] Example 4

[0042] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0043] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.3wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0044] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, respectively, and the addition time was 180min and 210min, respectively, and the reaction was continued for 1h, and 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, and the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 1wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0045] S3. According to the required proportion, 300kg of cement, 30kg of mineral powder, 80kg of Class F Grade II fly ash, 100kg of 150-mesh granite powder, 820kg of machine-made sand with a fineness modulus of 2.9, 950kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, stirred for 2 minutes, and the low-activity adhesive self-compacting concrete was obtained.

[0046] Example 5

[0047] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0048] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0049] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, the dropping times were 180min and 210min, respectively, and the reaction was continued for 1h, 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0050] S3. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, and stirred for 2 minutes to obtain the low-activity adhesive self-compacting concrete.

[0051] Example 6

[0052] A method for preparing low-activity adhesive self-compacting concrete comprises the following steps:

[0053] S1. 42.0 kg N, N-dimethylacrylamide, 55.0 kg hydroxyethyl acrylate, 6.0 kg acrylamide, 10.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.6 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.2 kg thioglycolic acid and 2.0 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 251kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 850kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0054] S2. 280.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 5.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 73.0kg2-acrylamide-2-methylpropanesulfonic acid, 10.5kg2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 24.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.0kg of thioglycolic acid and 0.8kg of vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, respectively, and the addition time was 180min and 210min, respectively, and the reaction was continued for 1h, 198.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 3wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0055] S3. According to the required proportion, 300kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 270-mesh granite powder, 780kg of machine-made sand with a fineness modulus of 3.6, 850kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, stirred for 2 minutes, and the low-activity adhesive self-compacting concrete was obtained.

[0056] Comparative Example 1

[0057] A method for preparing self-compacting concrete comprises the following steps:

[0058] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0059] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 57.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, respectively, and the addition time was 180min and 210min, respectively, and the reaction was continued for 1h, and 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, and the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0060] S3. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, and stirred for 2 minutes to obtain the self-compacting concrete.

[0061] Compared with Example 5, the main difference of this comparative example is that the amount of 2-acrylamide-2-methylpropanesulfonic acid used in step S2 is 57.0 kg.

[0062] Comparative Example 2

[0063] A method for preparing self-compacting concrete comprises the following steps:

[0064] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0065] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept at 50°C to obtain a reaction solution; 75.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, respectively, and the addition time was 180min and 210min, respectively, and the reaction was continued for 1h, and 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, and the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0066] S3. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, and stirred for 2 minutes to obtain the self-compacting concrete.

[0067] Compared with Example 5, the main difference of this comparative example is that the amount of 2-acrylamide-2-methylpropanesulfonic acid used in step S2 is 75.0 kg.

[0068] Comparative Example 3

[0069] A method for preparing self-compacting concrete comprises the following steps:

[0070] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 8.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0071] S2. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of modified gravel prepared in S1, 9kg of water reducer and 165kg of water were weighed and placed in a mixer to mix evenly and stirred for 2 minutes to obtain the self-compacting concrete.

[0072] Compared with Example 5, the main difference in this comparative example is that ordinary water reducing agent is used instead of modified water reducing agent.

[0073] Comparative Example 4

[0074] A method for preparing self-compacting concrete comprises the following steps:

[0075] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 5.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0076] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, the dropping times were 180min and 210min, respectively, and the reaction was continued for 1h, 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0077] S3. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, and stirred for 2 minutes to obtain the self-compacting concrete.

[0078] Compared with Example 5, the main difference of this comparative example is that the amount of 3-(methacryloyloxy)propyltrimethoxysilane used in step S1 is 5 kg.

[0079] Comparative Example 5

[0080] A method for preparing self-compacting concrete comprises the following steps:

[0081] S1. 38.0 kg N, N-dimethylacrylamide, 60.0 kg hydroxyethyl acrylate, 8.0 kg acrylamide, 12.0 kg 3-(methacryloyloxy)propyltrimethoxysilane and 0.9 kg N, N'-methylenebisacrylamide were mixed to obtain liquid B1; 1.6 kg thioglycolic acid and 1.5 kg L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50 wt.% liquid B1 and 50 wt.% liquid B2 were mixed and 2 kg 30% concentration of hydrogen peroxide, continue stirring, drop the remaining 50wt.% B1 liquid and 50wt.% B2, the dropping time is 90min, after the dropping is completed, continue stirring and keeping warm for 1h, add 260kg water to dilute to 12.5% ​​solid content, and then dilute 100 times to obtain a surface modifier, weigh 950kg of stone with a particle size of 5-25mm, spray the surface modifier on the surface of the stone, the spraying amount is 0.5wt.% of the stone mass, let it stand for 5min, and the modified stone is obtained for standby use;

[0082] S2. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction solution; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction solution, the dropping times were 180min and 210min, respectively, and the reaction was continued for 1h, 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother solution, the dispersant mother solution was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother solution, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0083] S3. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of modified gravel prepared by S1, 9kg of modified water-reducing agent prepared by S2 and 165kg of water were weighed, placed in a mixer and mixed evenly, and stirred for 2 minutes to obtain the self-compacting concrete.

[0084] Compared with Example 5, the main difference of this comparative example is that the amount of 3-(methacryloyloxy)propyltrimethoxysilane used in step S1 is 12 kg.

[0085] Comparative Example 6

[0086] A method for preparing self-compacting concrete comprises the following steps:

[0087] S1. 310.0kg of methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2400 was dissolved in water, 3.0kg30% hydrogen peroxide was added, and the mixture was kept warm at 50°C to obtain a reaction base liquid; 67.0kg 2-acrylamide-2-methylpropanesulfonic acid, 23.1kg 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and 26.0kg acrylic acid were dissolved in water and stirred to obtain a dropwise addition liquid F1; 1.4kg thioglycolic acid and 1.0kg vitamin C were dissolved in water and stirred to obtain a dropwise addition liquid F2; the dropwise addition liquids F1 and F2 were added dropwise to the reaction base liquid, the dropping times were 180min and 210min, respectively, the reaction was continued for 1h, 208.0kg of water was added and diluted to a mass concentration of 50%, to obtain a dispersant mother liquor, the dispersant mother liquor was mixed with a water reducer to obtain a water reducer containing 2wt.% of the dispersant mother liquor, to obtain the modified water reducer, and the modified water reducer was prepared for standby use;

[0088] S2. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of gravel, 9kg of the modified water-reducing agent prepared in S1 and 165kg of water were weighed and placed in a mixer to mix evenly and stirred for 2 minutes to obtain the self-compacting concrete.

[0089] Compared with Example 5, the main difference of this comparative example is that ordinary stones are used instead of modified stones.

[0090] Comparative Example 7

[0091] A method for preparing self-compacting concrete comprises the following steps:

[0092] S1. According to the required proportion, 280kg of cement, 50kg of mineral powder, 80kg of Class F II fly ash, 120kg of 150-mesh granite powder, 700kg of machine-made sand with a fineness modulus of 2.8, 950kg of gravel, 9kg of water reducer and 165kg of water were weighed and placed in a mixer to mix evenly and stirred for 2 minutes to obtain the self-compacting concrete.

[0093] Compared with Example 5, the main differences in this comparative example are that ordinary stone is used instead of modified stone, and ordinary water reducing agent is used instead of modified water reducing agent.

[0094] The above embodiments and comparative examples were subjected to performance tests, and the experimental test methods were as follows:

[0095] The slump expansion of the concrete obtained in the above embodiments and comparative examples was tested with reference to the method specified in the Technical Code for Application of Self-Compacting Concrete (JGJ_T283-2012); the compressive strength of self-compacting concrete at 7d and 28d was determined in accordance with the relevant provisions of the Standard for Test Methods for Physical and Mechanical Properties of Concrete (GB / T50081-2019), and the specimen size was 100mm×100mm×100mm.

[0096] The result is as follows:

[0097] Table 1 Test results of self-compacting concrete performance of Examples 1-6 and Comparative Examples 1-7 of the present invention

[0098]

[0099]

[0100] As can be seen from Table 1, the low-activity adhesive self-compacting concrete prepared by the technical solution of the present invention, Examples 1-6 all have excellent working performance, the 7d compressive strength is greater than 30MPa, the 28d compressive strength is greater than 50MPa, T500 is an important indicator of the flow rate of self-compacting concrete, and the slump expansion is a key indicator of the flowability of self-compacting concrete. The T500 of Examples 1 to 6 is 3.2s-4.1s, and the slump expansion is 680-705mm; it has excellent flow performance and excellent wrapping performance. The surface is smooth after demolding, and no stones are seen, which overcomes the problems of poor wrapping, poor flowability and other working performance of self-compacting concrete.

[0101] The amount of 2-acrylamide-2-methylpropane sulfonic acid in step S2 of comparative example 1 is 57.0 kg, which is 5.9 s longer than the T500 time of example 5, and the slump spread is reduced to 615 mm, indicating that the dispersant mother solution contains insufficient strongly adsorbed sulfonic acid groups, which has a poor dispersing effect on stone powder, resulting in a slow flow rate of concrete and poor fluidity of self-compacting concrete; the amount of 2-acrylamide-2-methylpropane sulfonic acid in step S2 of comparative example 2 is 75.0 kg, and too many sulfonic acid groups in the dispersant will produce competitive adsorption, which will make T500 become 8. 6s, the slump expansion decreased to 620mm, affecting the dispersion effect of the water reducer on the adhesive; in Comparative Example 3, ordinary water reducer was used instead of modified water reducer, and T500 was extended to 16.3s. Compared with Example 5, the slump expansion decreased by 150mm (decreased by 21.7%), and the self-compacting concrete had poor fluidity; in Comparative Example 4S1, the dosage of step 3-(methacryloyloxy)propyltrimethoxysilane was 5kg, which affected the modification effect of the surface modifier on the stone. The concrete performance was manifested as poor wrapping performance and exposed stone. The concrete surface after demolding also had the problem of exposed stone, and it could not reach to the effect of self-compacting concrete; in comparative example 5S1, the dosage of step 3-(methacryloyloxy)propyltrimethoxysilane is 12kg, and the methoxysilane group in the surface modifier solution is easily condensed and precipitated, which affects the modification effect of the surface modifier on the stone, so that the concrete performance is poor in packaging performance and exposed stone. There is also a problem of exposed stone on the concrete surface after demolding, which also has a negative effect on the strength of the concrete; in comparative example 6, ordinary stone is used instead of modified stone. The concrete performance is poor in packaging performance and exposed stone. There is more exposed stone on the concrete surface after demolding, and the concrete The unevenness has a negative effect on the strength of the concrete; in Comparative Example 7, ordinary gravel is used instead of modified gravel, and ordinary water-reducing agent is used instead of modified water-reducing agent. The slump expansion of the concrete is reduced from 690mm to 510mm, which is less than 550mm specified in the "Technical Code for Application of Self-compacting Concrete" JGJ / T283, and the slump expansion index cannot meet the requirements of self-compacting concrete; without modifying the surface of the gravel with the surface modifier of the present invention, the wrapping performance of the concrete is poor, the stone is exposed, and the concrete surface after demolding is exposed, which seriously affects the appearance of the concrete.

[0102] In summary, the low-activity adhesive self-compacting concrete of the present invention uses cheap inert stone powder to replace active adhesive, which reduces the amount of active adhesive in the self-compacting concrete and effectively reduces the material cost. A dispersant mother liquor with a high proportion of strongly adsorbed sulfonate and phosphate groups is introduced into the water reducer, which can be effectively adsorbed on the surface of the inert stone powder particles to achieve the effect of dispersing the stone powder, thereby ensuring that the self-compacting concrete has good fluidity and working performance. At the same time, in order to ensure the wrapping and homogeneity of self-compacting concrete, the present invention performs surface modification on gravel, and the modifier molecules have a large number of inorganic material-philic silanol groups and hydrophilic amide groups. When the gravel is mixed into the concrete, the modifier not only gives the gravel surface better viscosity, but also can be more quickly integrated into the cement paste. In addition, the hydrophilic end of the modifier is well compatible with the concrete paste, which enhances the gripping effect of the gravel on the paste, making the connection between the gravel and the paste tighter, solving the problem of the gravel not hanging on the paste, and solving the problem of poor wrapping of low-activity adhesive self-compacting concrete. The obtained low-activity adhesive self-compacting concrete has low cost, and overcomes the working performance problems of poor wrapping, poor fluidity and other working performance of self-compacting concrete, has good environmental and economic benefits, is suitable for large-scale promotion and industrialized production, and has positive significance for promoting the sustainable development of the construction industry.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing low-activity adhesive self-compacting concrete, characterized in that: The following steps are involved: S1. N, N-dimethylacrylamide, hydroxyethyl acrylate, acrylamide, 3-(methacryloyloxy)propyltrimethoxysilane and N, N'-methylenebisacrylamide were mixed to obtain liquid B1; thioglycolic acid and L-ascorbic acid were dissolved in water and mixed to obtain liquid B2; 50wt.% liquid B1 and 50wt.% liquid B2 were mixed, 30% concentration of hydrogen peroxide was added, stirring was continued, and the remaining 50wt.% liquid B1 and 50wt.% B2 were added dropwise for 80-100min, kept warm for 1h, diluted with water to obtain a surface modifier, and the surface modifier was sprayed on the surface of the stone to obtain the modified stone for standby use; S2. Dissolve methyl allyl alcohol polyoxyethylene ether with a relative molecular weight of 2200-2600 in water, add 30% concentration of hydrogen peroxide, and keep warm at 45-55°C to obtain a reaction base liquid; dissolve 2-acrylamide-2-methylpropanesulfonic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate and acrylic acid in water, stir evenly, and obtain a drop liquid F1; dissolve thioglycolic acid and vitamin C in water, stir evenly, and obtain a drop liquid F2; drop liquids F1 and F2 are respectively added dropwise to the reaction base liquid, and the dropping time is 160-200min and 200-220min, respectively, and the reaction is continued for 1h, and diluted with water to a mass concentration of 50% to obtain a dispersant mother liquor, and the dispersant mother liquor is mixed with a water reducer to obtain the modified water reducer, and stand-by; S3. Cement, mineral powder, fly ash, stone powder, machine-made sand and the modified gravel prepared in S1, the modified water-reducing agent prepared in S2 and water are weighed according to the required proportion, mixed evenly, and stirred for 2-5 minutes to obtain the low-activity adhesive self-compacting concrete.

2. A method for preparing low-activity adhesive self-compacting concrete according to claim 1, characterized in that: The mass ratio of N,N-dimethylacrylamide, hydroxyethyl acrylate, acrylamide, 3-(methacryloyloxy)propyltrimethoxysilane, N,N'-methylenebisacrylamide, thioglycolic acid, L-ascorbic acid and hydrogen peroxide described in S1 is (38-42):(55-60):(6-8):(8-10):(0.6-0.9):(1.2-1.6):(1.5-2.0):

2.

3. A method for preparing low-activity adhesive self-compacting concrete according to claim 1, characterized in that: The mass ratio of the surface modifier to the stone in S1 is (0.003-0.008):

1.

4. A method for preparing low-activity adhesive self-compacting concrete according to claim 1, characterized in that: The mass ratios of methyl allyl alcohol polyoxyethylene ether, hydrogen peroxide, 2-acrylamide-2-methylpropane sulfonic acid, 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate, acrylic acid, thioglycolic acid and vitamin C described in S2 are (280-310):(3-5):(67-73):(10.5-23.1):(24-26):(1.0-1.4):(0.8-1.0).

5. A method for preparing low-activity adhesive self-compacting concrete according to claim 1, characterized in that: The mass ratio of the dispersant mother solution and the water reducing agent in S2 is (0.01-0.04):

1.

6. A method for preparing low-activity adhesive self-compacting concrete according to claim 1, characterized in that: The components of S3 are calculated by weight and include 250-300 parts by weight of cement, 30-50 parts by weight of mineral powder, 50-80 parts by weight of fly ash, 80-120 parts by weight of stone powder, 700-820 parts by weight of machine-made sand, 850-950 parts by weight of modified gravel, 7-13 parts by weight of modified water reducing agent and 155-170 parts by weight of water.

7. A method for preparing low-activity adhesive self-compacting concrete according to claim 1, characterized in that: The fly ash is Class F II and / or Class F I; the parent rock of the stone powder is one or more of granite, limestone or cobblestone; the fineness modulus of the machine-made sand is 2.5-3.6; the stone powder is 100-270 mesh; and the particle size of the gravel is 5-25 mm.

8. A method for preparing low-activity adhesive self-compacting concrete according to claim 7, characterized in that: The fineness modulus of the machine-made sand is 2.6-3.4; the stone powder is 120-200 meshes.

9. A low-activity adhesive self-compacting concrete, characterized in that: The method for preparing low-activity adhesive self-compacting concrete is according to any one of claims 1 to 8.

10. A low-activity adhesive self-compacting concrete according to claim 9, characterized in that: Used to prepare self-compacting concrete.

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