阅读说明：本技术 一种加密硅灰复合掺合料及其在高性能混凝土中的应用 (Encrypted silica fume composite admixture and application thereof in high-performance concrete ) 是由 吉卫星 于 2021-07-21 设计创作，主要内容包括：本发明提供一种加密硅灰复合掺合料及其在高性能混凝土中的应用,所述复合掺合料的原料包括：加密硅灰、石灰石、锰渣、镍渣。复合掺合料在高性能混凝土中的应用,步骤如下：1)复合掺合料的粉磨制备：按质量百分比称量各原料,然后将原料输入磨机中进行粉磨；2)将复合掺合料通过储存罐运输到商混站后,往搅拌机中投入粗细骨料、胶凝材料进行搅拌,即得成品。本发明的优点：1.掺合料颗粒级配优化,有效改善混凝土的性能和后期强度；2.硅灰制备成复合掺合料,便于进行运输；3.掺合料在混凝土中胶凝材料的比例较大,制备过程中能够准确计量；4.掺合料在制备混凝土搅拌过程中,能够均匀分散在混凝土中,确保高性能混凝土质量稳定。(The invention provides an encrypted silica fume composite admixture and application thereof in high-performance concrete, wherein the composite admixture comprises the following raw materials: and (3) encrypting the silica fume, limestone, manganese slag and nickel slag. The application of the composite admixture in high-performance concrete comprises the following steps: 1) grinding preparation of the composite admixture: weighing the raw materials according to the mass percentage, and then inputting the raw materials into a grinding machine for grinding; 2) and (3) transporting the composite admixture to a commercial mixing station through a storage tank, and then adding coarse and fine aggregates and a cementing material into a stirrer for stirring to obtain a finished product. The invention has the advantages that: 1. the grading of the admixture particles is optimized, and the performance and the later strength of the concrete are effectively improved; 2. the silica fume is prepared into the composite admixture, so that the transportation is convenient; 3. the proportion of the admixture in the concrete is large, and the admixture can be accurately metered in the preparation process; 4. the admixture can be uniformly dispersed in the concrete in the process of preparing the concrete and stirring, so that the quality stability of the high-performance concrete is ensured.)

1. The composite admixture of the encrypted silica fume is characterized in that: the raw materials of the composite admixture comprise: the method comprises the following steps of encrypting silica fume, limestone, manganese slag and nickel slag, wherein the raw materials comprise the following components in percentage by mass: 15-25% of encrypted silica fume, 40-60% of limestone, 10-20% of manganese slag and 15-20% of nickel slag.

2. The composite admixture of densified silica fume as set forth in claim 1, wherein: the composite admixture comprises the following raw materials in percentage by mass: 15% of encrypted silica fume, 60% of limestone, 10% of manganese slag and 15% of nickel slag.

3. The composite admixture of densified silica fume as set forth in claim 1, wherein: the composite admixture comprises the following raw materials in percentage by mass: 18% of encrypted silica fume, 55% of limestone, 10% of manganese slag and 17% of nickel slag.

4. The composite admixture of densified silica fume as set forth in claim 1, wherein: the composite admixture comprises the following raw materials in percentage by mass: 25% of encrypted silica fume, 40% of limestone, 15% of manganese slag and 20% of nickel slag.

5. The composite admixture of densified silica fume as set forth in claim 1, wherein: the composite admixture comprises the following raw materials in percentage by mass: 25% of encrypted silica fume, 40% of limestone, 20% of manganese slag and 15% of nickel slag.

6. The application of the composite admixture of the encrypted silica fume in the high-performance concrete according to the claim 1 is characterized in that the steps are as follows:

1) grinding preparation of the composite admixture: weighing the raw materials according to the mass percentage, then inputting the raw materials into a grinding machine for grinding, wherein the grinding time of the materials in the grinding machine is 20-30min, and the fineness of the composite admixture is controlled to be 45um, and the screen residue is 15+ 2%;

2) transporting the composite admixture to a commercial mixing station through a storage tank, and then adding coarse and fine aggregates and a cementing material into a stirrer for stirring, wherein the mass percentage of the composite admixture in the cementing material is 30-50%, and the stirring time is as follows: and (5) obtaining a concrete finished product after 60-120 s.

7. The use of the composite admixture of densified silica fume according to claim 6 in high performance concrete, wherein: in the step 1), in the grinding process, the ground composite admixture is subjected to chemical analysis, and the blanking speed of the encrypted silica fume is adjusted in real time according to the detected components of the ground material, so that the metering accuracy of the encrypted silica fume in the composite admixture is ensured.

8. The use of the composite admixture of densified silica fume according to claim 6 in high performance concrete, wherein: in the step 2), the cementing material comprises a composite admixture, cement, water and an additive.

Technical Field

The invention belongs to the field of concrete materials, and particularly relates to a composite admixture of encrypted silica fume and application thereof in high-performance concrete.

Background

The silica fume is SiO generated in the process of smelting ferrosilicon alloy and industrial silicon₂And Si gas and oxygen in the air are quickly oxidized and condensed to form the superfine silicon powder material. The silicon ash is a byproduct in industrial smelting, dust removal and environmental protection equipment is required to be used for recycling in the whole process, the average particle size of the silicon ash is 0.1-0.3 mu m, the specific surface area is about 20000m2/kg, the volume weight is 200-250 kg/m3, and because the weight is light, encryption equipment is required to be used for encryption. The densified silica fume is a product obtained by densifying dry and fluffy silica fume which is not densified. These productsHigh density and economical transportation. They can be treated like portland cement or fly ash from concrete plants. The volume of the undisturbed silica fume can be greatly reduced by the encryption process.

The silica fume particles are smaller, so that the silica fume particles can fill the pores among the cementing material particles and simultaneously generate gel with a hydration product. The high-performance concrete is doped with a proper amount of silica fume, so that the concrete has the following functions: (1) the strength grade of the concrete is improved, and the strength of the concrete can reach more than C100; (2) has the functions of preserving water, preventing segregation and bleeding and greatly reducing the pumping resistance of concrete; (3) the cost can be reduced and the durability of the concrete can be improved in the application of the concrete. The silica fume is a necessary material for high-strength and high-performance concrete.

The existing technical method for preparing high-performance concrete by using silica fume comprises the steps of sequentially adding coarse and fine aggregate, cement, silica fume, admixture, water and admixture into a stirrer of a commercial mixing station, mixing the concrete, then discharging the concrete to a concrete tank truck, transporting the concrete to a construction site, and pumping for application, wherein the whole mixing time is about 30-40 s.

The prior art has the following defects: (1) the silica fume has small particles, high adsorptivity and poor dispersibility, and when the silica fume is conveyed to a storage tank of a commercial mixing station, the conveying time is long, so that the working efficiency is reduced; (2) the dosage of the silica fume accounts for 5-8% of the mass of the cementing material, the dosage is less, the conveying performance is poor, the measurement of the silica fume is difficult to ensure to be accurate, the calibration time is longer, and the quality of the concrete is influenced. (3) The silica fume is difficult to be uniformly mixed in a short time (30-40s) in the preparation of the high-performance concrete, the silica fume is not uniformly dispersed, the effect is difficult to be exerted, and the quality of the high-performance concrete is influenced.

How to overcome the above disadvantages is a problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a composite admixture of encrypted silica fume and application thereof in high-performance concrete, which effectively enhance the working performance and strength of the concrete and improve the strength and durability of the concrete.

In order to achieve the purpose, the composite admixture of the encrypted silica fume comprises the following raw materials: the method comprises the following steps of encrypting silica fume, limestone, manganese slag and nickel slag, wherein the raw materials comprise the following components in percentage by mass: 15-25% of encrypted silica fume, 40-60% of limestone, 10-20% of manganese slag and 15-20% of nickel slag.

Preferably, the composite admixture comprises the following raw materials in percentage by mass: 15% of encrypted silica fume, 60% of limestone, 10% of manganese slag and 15% of nickel slag.

Preferably, the composite admixture comprises the following raw materials in percentage by mass: 18% of encrypted silica fume, 55% of limestone, 10% of manganese slag and 17% of nickel slag.

Preferably, the composite admixture comprises the following raw materials in percentage by mass: 25% of encrypted silica fume, 40% of limestone, 15% of manganese slag and 20% of nickel slag.

Preferably, the composite admixture comprises the following raw materials in percentage by mass: 25% of encrypted silica fume, 40% of limestone, 20% of manganese slag and 15% of nickel slag.

Further, the application of the composite admixture of the encrypted silica fume in the high-performance concrete comprises the following steps:

1) grinding preparation of the composite admixture: weighing the raw materials according to the mass percentage, then inputting the raw materials into a grinding machine for grinding, wherein the grinding time of the materials in the grinding machine is 20-30min, and the fineness of the composite admixture is controlled to be 45um, and the screen residue is 15+ 2%;

2) transporting the composite admixture to a commercial mixing station through a storage tank, and then adding coarse and fine aggregates and a cementing material into a stirrer for stirring, wherein the mass percentage of the composite admixture in the cementing material is 30-50%, and the stirring time is as follows: and (5) obtaining a concrete finished product after 60-120 s.

Preferably, in the step 1), in the grinding process, the ground composite admixture is chemically analyzed, and the blanking speed of the encrypted silica fume is adjusted in real time according to the detected components of the ground material, so as to ensure the metering accuracy of the encrypted silica fume in the composite admixture.

Preferably, in the step 2), the cementing material comprises a composite admixture, cement, water and an additive.

The substantive characteristics and the remarkable progress of the invention are as follows:

the composite admixture of the encrypted silica fume and the application thereof in the high-performance concrete have the following beneficial effects:

(1) in the composite admixture, the limestone is easy to grind, has more fine powder and large proportion, and aims to be fully and uniformly mixed with the encrypted silica fume and improve the flowing property of concrete; the manganese slag and the nickel slag have poor grindability, more coarse particles and large gaps among particles, and the encrypted silica fume can be filled in the gaps among the particles. The particle composition of the composite admixture is optimized, and the performance and later strength of the concrete are effectively improved.

(2) During the grinding process of the composite admixture, the spherical particles of the silica fume have the effect of grinding aid, and the yield is increased by more than 5%. In the grinding process, the encrypted silica fume can be mutually filled and uniformly dispersed with limestone fine powder, the encrypted silica fume can be filled in gaps between manganese slag particles and nickel slag particles, and the grading distribution of the whole admixture is optimized, so that the working performance and the strength of the concrete can be improved, and the strength and the durability of the concrete can be improved. In addition, after the encrypted silica fume is ground, the particles are more round, the hydration effect of the encrypted silica fume is more obvious, and the durability of the concrete is also improved.

(3) The problems of small encrypted silica fume particles, poor dispersibility, low flow rate and poor transportation performance are solved. The composite admixture is prepared by the encrypted silica fume, and is convenient to transport.

(4) The problem of concrete quality fluctuation caused by the fact that silica fume is difficult to measure accurately when directly applied to concrete is solved. The proportion of the cementing material of the composite admixture in the concrete is 30-50 percent, and the proportion is large, so that the concrete can be accurately measured in the process of preparing the concrete.

(5) Solves the problems that the dispersibility of the encrypted silica fume is poor and the silica fume is difficult to stir uniformly in a short time when preparing concrete. Various raw materials in the composite admixture are uniformly mixed, and can be uniformly dispersed in concrete in the process of preparing concrete and stirring, so that the stable quality of high-performance concrete is ensured.

Detailed Description

The technical scheme of the invention is further illustrated by the following specific examples.

First, an embodiment

1) Grinding preparation of the composite admixture:

weighing the raw materials according to the mass percent, wherein the encrypted silica fume is 18 percent, the limestone is 55 percent, the manganese slag is 10 percent, and the nickel slag is 17 percent.

Then the raw materials are input into a mill for grinding, the grinding time of the materials in the mill is 20-30min, and the fineness of the composite admixture is controlled to be 45um, and the screen residue is 15+ 2%. In the grinding process, the milled composite admixture is subjected to chemical analysis, and the blanking speed of the encrypted silica fume is adjusted in real time according to the detected components of the milled material, so that the metering accuracy of the encrypted silica fume in the composite admixture is ensured.

2) Transporting the composite admixture to a commercial mixing station through a storage tank, and then adding coarse and fine aggregates and a cementing material into a stirrer for stirring, wherein the mass percentage of the composite admixture in the cementing material is 30-50%, and the stirring time is as follows: and (5) obtaining a concrete finished product after 60-120 s.

Wherein, the cementing material comprises a composite admixture, cement, water and an additive.

Second, comparative experiment

The test data of the direct use of the densified silica fume and the composite admixture in the C60 concrete are compared as follows:

wherein the composite admixture comprises the following raw materials in percentage by mass: 18% of encrypted silica fume, 55% of limestone, 10% of manganese slag and 17% of nickel slag.

From the data, the working performance and the mechanical property of the concrete are obviously improved after the encrypted silica fume is used in the concrete.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that are not thought of through the inventive work should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.