Densified silica fume composite admixture and application thereof in high-performance concrete

Abstract

The invention provides a densified silica fume composite admixture and application thereof in high-performance concrete. The composite admixture is prepared from the following raw materials: densified silica fume, limestone, manganese slag and nickel slag. The application of the composite admixture in the high-performance concrete comprises the steps of 1) conducting powder grinding preparation of the composite admixture, specifically, weighing the raw materials in percentage by mass, and then inputting the raw materials into a grinding machine for powder grinding; and 2) transporting the composite admixture to a commercial mixing station through a storage tank, adding coarse and fine aggregate and a cementing material into a stirrer, and stirring to obtain a finished product. The invention has the following advantages: 1, the admixture grain composition 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 cementing material in the concrete is large, and the admixture can be accurately metered in the preparation process; and 4, the admixture can be uniformly dispersed in the concrete in the stirring process of preparing the concrete, so that the stable quality of the high-performance concrete is ensured.

Description

technical field [0001] The invention belongs to the field of concrete materials, and in particular relates to an encrypted silica fume composite admixture and its application in high-performance concrete. Background technique [0002] Silica fume is SiO produced during the smelting of ferrosilicon alloy and industrial silicon 2 It is an ultrafine silicon powder material formed by rapid oxidation and condensation of Si gas and oxygen in the air. It is a by-product of industrial smelting, and the whole process needs to be recycled by dust removal and environmental protection equipment. The average particle size of silica fume is 0.1-0.3μm, the specific surface area is about 20000m2 / kg, and the bulk density is 200-250kg / m3, because the quality is relatively light , also needs to be encrypted with an encryption device. Densified silica fume is the densified product of dry, fluffy undisturbed (unencrypted) silica fume. These products are dense and economical to transport. The...

AI Technical Summary

Problems solved by technology

[0005] The disadvantages of the existing technology: (1) silica fume particles are small, high in adsorption, and poor in dispersibility. When the silica fume is transported to the storage tank of the commercial mixing station, the transportation time is long and the work efficiency is reduced; (2) The amount of silica fume accounts for 5-8% of the mass of the cementitious material, the amount is small, the conveying performance is poor, the measurement of silica fume is difficult to ensure accurate, and the calibration time is long, which affects the quality of concrete

(3) Silica fume is difficult to mix evenly in a short period of time (30-40s) in the preparation of high-performance concrete, and the dispersion of silica fume is uneven, and the effect is difficult to exert, which affects the quality of high-performance concrete

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