C60 self-compacting concrete mixed with admixture and preparation method thereof

Abstract

The application relates to the field of building materials, in particular to a C60 self-compacting concrete mixed with admixture and a preparation method thereof. Technical points are as follows: according to mass percentage calculation, the following components are included: cement 16-19%, viscosity reducer 2-4%, slag powder 2-4%, silica fume 1-2%, fine aggregate 30-35%, coarse aggregate 37-40%, water 6-8% and polycarboxylic acid water reducer 0.2-0.3%; wherein, the fine aggregate is mixed sand containing machine-made sand and natural river sand; the dosage of the machine-made sand is determined by the particle size distribution of the machine-made sand and the particle size distribution of the natural river sand. In the self-compacting concrete provided by the application, the artificial sand replaces part of the natural sand, which can not only solve the problem of shortage of natural river sand and protect natural resources, but also save cost, and according to the mixing ratio between the artificial sand and the natural sand, the mechanical properties such as the compressive strength and the fluidity of the self-compacting concrete are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of building materials, specifically to a C60 self-compacting concrete with admixtures and its preparation method. Background Technology

[0002] With the development of China's economy, concrete, with its relatively low price and high performance, has been widely used in construction projects, becoming an indispensable and important engineering material. However, insufficient flowability during concrete pouring can affect transportation and construction, potentially leading to material waste and impacting building quality. As demands for concrete performance, construction quality, and cost-effectiveness in building construction increase, self-compacting concrete, compared to ordinary concrete, exhibits high flowability, non-segregation, homogeneity, and stability. During pouring, it flows under its own weight, completely filling the formwork even with dense reinforcing steel, while achieving excellent homogeneity. It achieves dense concrete without vibration, and its mixture does not exhibit segregation or bleeding.

[0003] In construction engineering, self-compacting concrete can ensure good compaction of concrete, improve production efficiency, improve the surface quality of concrete, increase the freedom of structural design, and improve the working environment and safety.

[0004] Replacing some natural sand with manufactured sand in self-compacting concrete can not only solve the problem of insufficient natural river sand and protect natural resources, but also save costs. However, the existing technology does not limit the mixing ratio between manufactured sand and natural sand. The mixing of different natural river sand and manufactured sand has a significant impact on the mechanical properties of self-compacting concrete, which greatly limits the application of manufactured sand in self-compacting concrete.

[0005] In view of the deficiencies of the existing technology, the inventor, based on years of experience and expertise in this field, combined with theoretical analysis and research innovation, has developed a C60 self-compacting concrete with admixtures and its preparation method. Summary of the Invention

[0006] The purpose of this invention is to develop a C60 self-compacting concrete with admixtures. The proportion of manufactured sand and natural river sand in the mixed sand is controlled according to the particle size distribution of manufactured sand and natural river sand, so as to ensure the fluidity and mechanical properties of the self-compacting concrete.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0008] The present invention provides a C60 self-compacting concrete with admixtures, which, according to mass percentage, comprises the following components: 16-19% cement, 2-4% viscosity reducer, 2-4% slag powder, 1-2% silica fume, 30-35% fine aggregate, 37-40% coarse aggregate, 6-8% water, and 0.2-0.3% polycarboxylate superplasticizer.

[0009] Among them, fine aggregate is a mixed sand containing manufactured sand and natural river sand; the amount of manufactured sand is determined by the particle size distribution of manufactured sand and the particle size distribution of natural river sand.

[0010] Specifically, manufactured sand is divided into four parts according to particle size: particles larger than 0.5 mm, particles between 0.35 and 0.5 mm, particles between 0.25 and 0.35 mm, and particles smaller than 0.25 mm. The mass ratio of manufactured sand with a particle size greater than 0.5 mm to the total mass of manufactured sand is denoted as m, and the mass ratio of manufactured sand with a particle size less than 0.25 mm to the total mass of manufactured sand is denoted as n.

[0011] The natural river sand was divided into four parts using the same method. The median percentage of the total natural river sand in each of the four parts was denoted as P, and the average percentage of the total natural river sand in each of the four parts was denoted as a. The ratio of manufactured sand to natural river sand was determined based on the values ​​of m and n, as well as the values ​​of p and a.

[0012] In this invention, the particle size distribution of manufactured sand and natural river sand is used to determine the ratio of manufactured sand to natural river sand. This avoids excessive differences in particle size distribution between manufactured sand and natural river sand, which could lead to collapse, and at the same time improves the compressive strength of self-compacting concrete.

[0013] Furthermore, when m > n and p > a, or m < n and p < a, calculate the ratio of processed sand to natural river sand using the following formula:

[0014] m 机制砂 / m 天然河砂 =a / m+p 2 / an; where m 机制砂 The mass of manufactured sand is expressed in kg and m³. 天然河砂 The mass of natural river sand is expressed in kg.

[0015] When m > n and p > a, or m < n and p < a, the particle size of both manufactured sand and natural river sand is relatively large. In this case, during the blending process of mixed sand, when the water content is fixed, a higher content of the large-particle-size portion of the manufactured sand results in better fluidity, but also a larger slump, which leads to a decrease in the compressive strength of the concrete. Therefore, the proportion of manufactured sand should be adjusted using the following formula: m 机制砂 / m 天然河砂 = p / m·a / p + p / n·p / a; thus obtaining m机制砂 / m 天然河砂 =a / m+p 2 The formula for / n.

[0016] Furthermore, when m < n and p > a, or when m > n and p < a, calculate the ratio of processed sand to natural river sand using the following formula:

[0017] m 机制砂 / m 天然河砂 =p / m·p / a+p / n·a / p=p 2 / am+a / n; where m 机制砂 The mass of manufactured sand is expressed in kg and m³. 天然河砂 The mass of natural river sand is expressed in kg.

[0018] When m < n and p > a, or m > n and p < a, it indicates that the particle size distribution in manufactured sand is opposite to that in natural river sand. In this case, the amount of manufactured sand added should be adjusted according to m. 机制砂 / m 天然河砂 =p / m·p / a+p / n·a / p=p 2 / am+a / n can improve the fluidity of self-compacting concrete by using sand with a large particle size, and increase the compressive strength by using sand with a small particle size, thus achieving the goal of ensuring both the fluidity and compressive strength of the self-compacting concrete.

[0019] Furthermore, the slag powder is granulated blast furnace slag powder with a specific surface area of ​​400 m². 2 / kg~500m 2 / kg.

[0020] When slag powder is added to concrete as an admixture to replace cement, it exhibits good stability and not only provides early-stage activity to the concrete, but its fineness also helps to fill the spaces between cement particles, promoting secondary hydration and thus ensuring the later-stage activity of the concrete.

[0021] Furthermore, silica ash consists of ultrafine silica particles with a specific surface area of ​​18,000 m². 2 / kg~22,000m 2 / kg.

[0022] Furthermore, viscosity reducers can be added to concrete instead of cement. These viscosity reducers are in the form of powdered particles that preferentially adsorb onto the surface of cement particles, reducing water absorption and friction between them. This lowers the viscosity of the concrete, thereby improving its fluidity. Moreover, the finer particle size of the viscosity reducer allows it to fill the spaces between cement particles, promoting cement hydration and ensuring the strength of the concrete.

[0023] Furthermore, the viscosity reducer is a hyperbranched organic polymer, comprising the following components by weight:

[0024] The ingredients are: 35-40 parts methacrylamide, 19-22 parts allyl polyethylene glycol, 22-26 parts vinyl silicone oil + methyl methacrylate, and 12-24 parts 4-tert-butylstyrene.

[0025] Silica fume, when added to concrete as an admixture to replace cement, exhibits a strong pozzolanic effect. When mixed with concrete, its average particle size is relatively small, resulting in a good filling effect. It can fill the gaps between cement particles and undergo a secondary hydration reaction with the cement hydration product Ca(OH)2 to form cementitious products, which fill the cement stone structure, improve the microstructure of the paste, and enhance the mechanical properties of the hardened body.

[0026] Furthermore, the coarse aggregate is a mixture of two types of crushed stone with different particle sizes: crushed stone with a particle size of 5-10 mm and crushed stone with a particle size of 10-20 mm, with a mixing mass ratio of 0.1-0.13.

[0027] Furthermore, the solid content of polycarboxylate-type high-efficiency water-reducing agents is 13-14%.

[0028] High-efficiency water-reducing agents can reduce the amount of water used in concrete while improving the fluidity of the concrete mixture and enhancing its workability, including slump spread, water retention, workability, and cohesiveness. Polycarboxylate-based water-reducing agents are preferred as they can significantly improve concrete workability. Higher water reduction rates result in lower relative water consumption, a smaller water-cement ratio, and higher concrete strength.

[0029] Furthermore, the water-cement ratio of C60 self-compacting concrete is 0.23 to 0.27.

[0030] The second objective of this invention is to provide a method for preparing C60 self-compacting concrete with admixtures:

[0031] The present invention provides a method for preparing C60 self-compacting concrete with admixtures, comprising the following steps:

[0032] S1. Mix the crushed stone, mixed sand and a portion of the mixing water until well combined;

[0033] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0034] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0035] Furthermore, in step S1, the crushed stone, manufactured sand, and a portion of the mixing water are first stirred evenly before natural river sand is added. Conventionally, manufactured sand and natural river sand are mixed evenly before being combined with crushed stone and water. In this invention, the manufactured sand, crushed stone, and water are mixed evenly first before adding natural river sand. The purpose of this is to disperse the manufactured sand through the addition of crushed stone and water, and then to ensure a more uniform mixture between the natural river sand and the manufactured sand when natural river sand is added.

[0036] In summary, the present invention has the following beneficial effects:

[0037] The self-compacting concrete provided by this invention replaces cement with slag powder, silica fume mineral admixtures, and viscosity reducers, reducing cement usage and thus lowering project costs to some extent. Replacing some natural sand with manufactured sand in the self-compacting concrete not only solves the problem of insufficient natural river sand and protects natural resources, but also saves costs. Furthermore, depending on the mixing ratio of manufactured sand to natural sand, the compressive strength, fluidity, and other mechanical properties of the self-compacting concrete are significantly improved. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific implementation method, features and effects of a C60 self-compacting concrete with admixtures and its preparation method according to the present invention are described in detail below.

[0039] The viscosity reducer used in this specific embodiment is a hyperbranched organic polymer, which, by weight, includes the following components:

[0040] 35 parts of methacrylamide, 19 parts of allyl polyethylene glycol, 13 parts of vinyl silicone oil, 13 parts of methyl methacrylate, and 24 parts of 4-tert-butylstyrene.

[0041] Example 1

[0042] A C60 self-compacting concrete with admixtures and its preparation method

[0043] The C60 self-compacting concrete provided in this embodiment includes the following components:

[0044] 432 kg of P.O42.5 cement, 70 kg of viscosity reducer, 50 kg of slag powder, 42 kg of silica fume, 782 kg of fine aggregate, 92 kg of 5-10 mm coarse aggregate, 826 kg of 10-20 mm coarse aggregate, 150 kg of water, and 7.8 kg of polycarboxylate superplasticizer.

[0045] Among them, fine aggregate is a mixed sand containing manufactured sand and natural river sand; the amount of manufactured sand is determined by the particle size distribution of manufactured sand and the particle size distribution of natural river sand.

[0046] Specifically, manufactured sand is divided into four parts according to particle size: particles larger than 0.5 mm, particles between 0.35 and 0.5 mm, particles between 0.25 and 0.35 mm, and particles smaller than 0.25 mm. The mass ratio of manufactured sand with a particle size greater than 0.5 mm to the total mass of manufactured sand is denoted as m, and the mass ratio of manufactured sand with a particle size less than 0.25 mm to the total mass of manufactured sand is denoted as n.

[0047] The natural river sand was divided into four parts using the same method. The median percentage of the total natural river sand in each of the four parts was denoted as P, and the average percentage of the total natural river sand in each of the four parts was denoted as a.

[0048] The particle size distribution of the manufactured sand and natural river sand used in this embodiment is as follows:

[0049]

[0050] Given m = 13.5, n = 11.4; p = 41.6, a = 25; and m > n and p > a, calculate the ratio of machined sand to natural river sand using the following formula:

[0051] m 机制砂 / m 天然河砂 =a / m+p 2 / an = 7.85; where m 机制砂 The mass of manufactured sand is expressed in kg and m³. 天然河砂 The mass of natural river sand is expressed in kg.

[0052] In this embodiment, the amount of manufactured sand is 693 kg and the amount of natural river sand is 89 kg.

[0053] The specific steps of the method for preparing C60 self-compacting concrete with admixtures provided in this embodiment are as follows:

[0054] S1. Mix the crushed stone, manufactured sand and a portion of mixing water evenly, then add natural river sand and mix evenly.

[0055] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0056] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0057] Example 2

[0058] A C60 self-compacting concrete with admixtures and its preparation method

[0059] The C60 self-compacting concrete provided in this embodiment includes the following components:

[0060] 432 kg of P.O42.5 cement, 70 kg of viscosity reducer, 50 kg of slag powder, 42 kg of silica fume, 782 kg of fine aggregate, 92 kg of 5-10 mm coarse aggregate, 826 kg of 10-20 mm coarse aggregate, 150 kg of water, and 7.8 kg of polycarboxylate superplasticizer.

[0061] Among them, fine aggregate is a mixed sand containing manufactured sand and natural river sand; the amount of manufactured sand is determined by the particle size distribution of manufactured sand and the particle size distribution of natural river sand.

[0062] Specifically, manufactured sand is divided into four parts according to particle size: particles larger than 0.5 mm, particles between 0.35 and 0.5 mm, particles between 0.25 and 0.35 mm, and particles smaller than 0.25 mm. The mass ratio of manufactured sand with a particle size greater than 0.5 mm to the total mass of manufactured sand is denoted as m, and the mass ratio of manufactured sand with a particle size less than 0.25 mm to the total mass of manufactured sand is denoted as n.

[0063] The natural river sand was divided into four parts using the same method. The median percentage of the total natural river sand in each of the four parts was denoted as P, and the average percentage of the total natural river sand in each of the four parts was denoted as a.

[0064] The particle size distribution of the manufactured sand and natural river sand used in this embodiment is as follows:

[0065]

[0066] Given m = 12.6, n = 17.4; p = 41.6, a = 25; m < n and p > a, calculate the ratio of machined sand to natural river sand using the following formula:

[0067] m_manufactured sand / m_natural river sand = p 2 / am+a / n=6.92; where m 机制砂 The mass of manufactured sand is expressed in kg and m³. 天然河砂 The mass of natural river sand is expressed in kg.

[0068] In this embodiment, the amount of manufactured sand is 639.5 kg and the amount of natural river sand is 92.5 kg.

[0069] The specific steps of the method for preparing C60 self-compacting concrete with admixtures provided in this embodiment are as follows:

[0070] S1. Mix the crushed stone, manufactured sand and a portion of mixing water evenly, then add natural river sand and mix evenly.

[0071] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0072] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0073] Example 3

[0074] A C60 self-compacting concrete with admixtures and its preparation method

[0075] The C60 self-compacting concrete provided in this embodiment includes the following components:

[0076] 432 kg of P.O42.5 cement, 70 kg of viscosity reducer, 50 kg of slag powder, 42 kg of silica fume, 782 kg of fine aggregate, 92 kg of 5-10 mm coarse aggregate, 826 kg of 10-20 mm coarse aggregate, 150 kg of water, and 7.8 kg of polycarboxylate superplasticizer.

[0077] Among them, fine aggregate is a mixed sand containing manufactured sand and natural river sand; the amount of manufactured sand is determined by the particle size distribution of manufactured sand and the particle size distribution of natural river sand.

[0078] Specifically, manufactured sand is divided into four parts according to particle size: particles larger than 0.5 mm, particles between 0.35 and 0.5 mm, particles between 0.25 and 0.35 mm, and particles smaller than 0.25 mm. The mass ratio of manufactured sand with a particle size greater than 0.5 mm to the total mass of manufactured sand is denoted as m, and the mass ratio of manufactured sand with a particle size less than 0.25 mm to the total mass of manufactured sand is denoted as n.

[0079] The natural river sand was divided into four parts using the same method. The median percentage of the total natural river sand in each of the four parts was denoted as P, and the average percentage of the total natural river sand in each of the four parts was denoted as a.

[0080] The particle size distribution of the manufactured sand and natural river sand used in this embodiment is as follows:

[0081]

[0082] Given m = 13.5, n = 11.4; p = 24.4, a = 25; and m > n and p < a, calculate the ratio of machined sand to natural river sand using the following formula:

[0083] m 机制砂 / m 天然河砂 =p 2 / am+a / n=6.92=7.85; where, m 机制砂 The mass of manufactured sand is expressed in kg and m³. 天然河砂 The mass of natural river sand is expressed in kg.

[0084] In this embodiment, the amount of manufactured sand is 584.4 kg and the amount of natural river sand is 147.5 kg.

[0085] The specific steps of the method for preparing C60 self-compacting concrete with admixtures provided in this embodiment are as follows:

[0086] S1. Mix the crushed stone, manufactured sand and a portion of mixing water evenly, then add natural river sand and mix evenly.

[0087] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0088] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0089] Example 4

[0090] A C60 self-compacting concrete with admixtures and its preparation method

[0091] The C60 self-compacting concrete provided in this embodiment includes the following components:

[0092] 432 kg of P.O42.5 cement, 70 kg of viscosity reducer, 50 kg of slag powder, 42 kg of silica fume, 782 kg of fine aggregate, 92 kg of 5-10 mm coarse aggregate, 826 kg of 10-20 mm coarse aggregate, 150 kg of water, and 7.8 kg of polycarboxylate superplasticizer.

[0093] Among them, fine aggregate is a mixed sand containing manufactured sand and natural river sand; the amount of manufactured sand is determined by the particle size distribution of manufactured sand and the particle size distribution of natural river sand.

[0094] Specifically, manufactured sand is divided into four parts according to particle size: particles larger than 0.5 mm, particles between 0.35 and 0.5 mm, particles between 0.25 and 0.35 mm, and particles smaller than 0.25 mm. The mass ratio of manufactured sand with a particle size greater than 0.5 mm to the total mass of manufactured sand is denoted as m, and the mass ratio of manufactured sand with a particle size less than 0.25 mm to the total mass of manufactured sand is denoted as n.

[0095] The natural river sand was divided into four parts using the same method. The median percentage of the total natural river sand in each of the four parts was denoted as P, and the average percentage of the total natural river sand in each of the four parts was denoted as a.

[0096] The particle size distribution of the manufactured sand and natural river sand used in this embodiment is as follows:

[0097]

[0098] Given m = 12.6, n = 17.4; p = 24.4, a = 25; and m < n and p < a, calculate the ratio of machined sand to natural river sand using the following formula:

[0099] m_manufactured sand / m_natural river sand = a / m + p 2 / an = 3.35; where m 机制砂 The mass of manufactured sand is expressed in kg and m³. 天然河砂 The mass of natural river sand is expressed in kg.

[0100] In this embodiment, the amount of manufactured sand is 563.7 kg and the amount of natural river sand is 168.3 kg.

[0101] The specific steps of the method for preparing C60 self-compacting concrete with admixtures provided in this embodiment are as follows:

[0102] S1. Mix the crushed stone, manufactured sand and a portion of mixing water evenly, then add natural river sand and mix evenly.

[0103] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0104] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0105] Comparative Example 1

[0106] A C60 self-compacting concrete with admixtures and its preparation method

[0107] The C60 self-compacting concrete provided in this embodiment includes the following components:

[0108] 432 kg of P.O42.5 cement, 70 kg of viscosity reducer, 50 kg of slag powder, 42 kg of silica fume, 782 kg of fine aggregate, 92 kg of 5-10 mm coarse aggregate, 826 kg of 10-20 mm coarse aggregate, 150 kg of water, and 7.8 kg of polycarboxylate superplasticizer.

[0109] The particle size distribution of the manufactured sand and natural river sand used in this embodiment is as follows:

[0110]

[0111] In this embodiment, the amount of manufactured sand is 391 kg and the amount of natural river sand is 391 kg.

[0112] The specific steps of the method for preparing C60 self-compacting concrete with admixtures provided in this embodiment are as follows:

[0113] S1. Mix the crushed stone, manufactured sand and a portion of mixing water evenly, then add natural river sand and mix evenly.

[0114] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0115] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0116] Comparative Example 2: A C60 self-compacting concrete and its preparation method.

[0117] The C60 self-compacting concrete provided in this embodiment includes the following components:

[0118] 432 kg of P.O42.5 cement, 72 kg of viscosity reducer, 50 kg of slag powder, 46 kg of silica fume, 782 kg of fine aggregate, 92 kg of 5-10 mm coarse aggregate, 826 kg of 10-20 mm coarse aggregate, 150 kg of water, and 7.8 kg of polycarboxylate superplasticizer.

[0119] In this embodiment, the amount of manufactured sand is 391 kg and the amount of natural river sand is 391 kg.

[0120] The specific steps of the method for preparing C60 self-compacting concrete with admixtures provided in this embodiment are as follows:

[0121] S1. Mix the crushed stone, manufactured sand and a portion of mixing water evenly, then add natural river sand and mix evenly.

[0122] S2. Add cement, viscosity reducer and silica fume in sequence and mix well;

[0123] S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2, and continue stirring to mix the raw materials evenly to obtain concrete.

[0124] Performance testing

[0125] The self-compacting performance requirements for concrete are shown in the table below. The test methods are in accordance with JGJ / T 283-2012 "Technical Specification for Application of Self-Compacting Concrete" and GB / T 50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures".

[0126]

[0127] The results above show that, compared with Comparative Example 1 and Comparative Example 1-2, when the mass ratio of manufactured sand to natural river sand is relatively small, the concrete prepared by the method disclosed in this application can improve its workability and compressive strength by replacing natural river sand with a large amount of manufactured sand.

[0128] Compared with Comparative Example 1 and Comparative Example 2, increasing the mass of silica fume and viscosity reducer increased the slump expansion of the concrete prepared by the method disclosed in this application, reduced the emptying time of the inverted slump cone, and slightly increased the strength of the concrete. This indicates that increasing the amount of silica fume and simultaneously increasing the amount of viscosity reducer can improve the workability and compressive strength of the concrete.

[0129] Comparing the examples prepared using the method described in this invention with Comparative Example 1, the mass ratio of manufactured sand to natural river sand was calculated based on the particle size distribution of manufactured sand and natural river sand. In the examples, the increased mass ratio of manufactured sand to natural river sand still ensured that the concrete had good flowability and compressive strength. This facilitates the replacement of natural river sand with manufactured sand, provides technical guidance for the application of manufactured sand, and is beneficial for the market promotion of the product.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been shown above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A C60 self-compacting concrete with admixtures, characterized in that, Calculated by weight percentage, it includes: cement 16~19%, viscosity reducer 2~4%, slag powder 2~4%, silica fume 1~2%, fine aggregate 30~35%, coarse aggregate 37~40%, water 6~8%, and polycarboxylate superplasticizer 0.2~0.3%; The fine aggregate is a mixture of manufactured sand and natural river sand; the amount of manufactured sand is determined by the particle size distribution of both manufactured sand and natural river sand. Manufactured sand is divided into four parts according to particle size: greater than 0.5mm, 0.35~0.5mm, 0.25mm~0.35mm, and less than 0.25mm. The mass ratio of manufactured sand with a particle size greater than 0.5mm to the total mass of manufactured sand is denoted as m, and the mass ratio of manufactured sand with a particle size less than 0.25mm to the total mass of manufactured sand is denoted as n. The same method is used to divide the natural river sand into four parts. The median percentage of the total natural river sand in each of the four parts is denoted as P, and the average percentage of the total natural river sand in each of the four parts is denoted as a. When m > n and p > a, or m < n and p < a, according to m 机制砂 / m 天然河砂 =a / m+p 2 / an The ratio of computer-generated sand to natural river sand; When m < n and p > a, or m > n and p < a, according to m 机制砂 / m 天然河砂 =p 2 / am+a / n The ratio of computer-generated sand to natural river sand; Where, m 机制砂 For the quality of manufactured sand, m 天然河砂 The mass of natural river sand is expressed in kg. The viscosity reducer is a hyperbranched organic polymer, which, by weight, includes the following components: 35-40 parts of methacrylamide, 19-22 parts of allyl polyethylene glycol, 22-26 parts of vinyl silicone oil + methyl methacrylate, and 12-24 parts of 4-tert-butylstyrene.

2. The C60 self-compacting concrete with admixtures according to claim 1, characterized in that, The slag powder is granulated blast furnace slag powder with a specific surface area of ​​400 m². 2 / kg~500m 2 / kg.

3. The C60 self-compacting concrete with admixtures according to claim 1, characterized in that, The silica fume is ultrafine silica particles with a specific surface area of ​​18,000 m². 2 / kg~22,000m 2 / kg.

4. A C60 self-compacting concrete with admixtures according to claim 1, characterized in that, The coarse aggregate is a mixture of two types of crushed stone with different particle sizes, specifically: crushed stone with a particle size of 5~10mm and crushed stone with a particle size of 10~20mm, with a mixing mass ratio of 0.1~0.

13.

5. A C60 self-compacting concrete with admixtures according to claim 1, characterized in that, The solid content of the polycarboxylate-type high-efficiency water-reducing agent is 13-14%.

6. A C60 self-compacting concrete with admixtures according to claim 1, characterized in that, The water-cement ratio of the C60 self-compacting concrete is 0.23~0.

27.

7. A method for preparing C60 self-compacting concrete with admixtures as described in any one of claims 1 to 6, characterized in that, The following steps are included: S1. Mix the crushed stone, mixed sand and a portion of the mixing water until well combined; S2. Add cement, viscosity reducer and silica fume in sequence and mix well; S3. Add the remaining water, slag powder and polycarboxylate high-performance water-reducing agent to step S2 respectively, and continue to stir to make the raw materials evenly mixed to obtain concrete.

8. The method for preparing C60 self-compacting concrete with admixtures according to claim 7, characterized in that, In step S1, crushed stone, manufactured sand and a portion of mixing water are first mixed evenly before natural river sand is added.

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