Active admixture, preparation method and application for active admixture, and concrete

Abstract

The invention discloses an active admixture, a preparation method and an application for the active admixture, and concrete, belonging to the technical field of building materials. The active admixture comprises the following components in parts by weight: 10-30 parts of Bayer process red mud, 5-15 parts of quicklime powder and 80-120 parts of limestone powder, wherein the water content of the Bayer process red mud is 15%-35%, and the mass content of aluminum oxide in the Bayer process red mud is 20%-40%. According to the invention, the Bayer process red mud and the limestone powder are used as main raw materials; the problem of difficult dehydration for the Bayer process red mud is solved by utilizing the principle of a violent reaction of quick lime and water; hydrated sodium aluminosilicate with high content and relatively good water solubility in the Bayer process red mud is utilized to react with the limestone powder to produce hydrated aluminosilicate; thus, the hydration activity of the active admixture can be improved; and the active admixture can completely replace fly ash to reduce the production cost of the building materials like the concrete.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to an active admixture, a preparation method and application of the active admixture and concrete. Background technique [0002] In the field of building materials, fly ash is an excellent auxiliary cementitious material, and has long been an important technical measure for concrete and other building material companies to reduce the cost of ingredients. However, as the proportion of new energy sources such as nuclear energy and wind energy in the national energy composition continues to increase, the traditional thermal power generation capacity gradually shrinks, resulting in insufficient supply of fly ash, a by-product of thermal power generation, and rising prices. On the contrary, The decline in thermal power generation has reduced the demand for limestone powder, the raw material used in desulfurization, and the insufficient market demand for limestone powder has le...

AI Technical Summary

Problems solved by technology

However, directly using limestone powder instead of fly ash to prepare concrete will lead to a series of quality problems such as rapid loss of work performance, insufficient strength, and increased cracks in the concrete. Therefore, it is currently impossible to use limestone powder to completely replace fly ash as concrete. Admixture

[0004] In addition, in the bulk industrial waste residue, the comprehensive utilization rate of red mud is relatively low, and its comprehensive utilization rate is only about 15%. Among the three alumina production processes of sintering method, Bayer method and combined method, Bayer method is currently the dominant one. Status, unlike sintering and combined red mud, Bayer red mud is rich in Fe(OH) 3 Gel and Al(OH) 3 Gel makes the red mud have strong water retention, is not easy to dry, and consumes a lot of energy for dehydration. Since the 1940s, many countries have proposed dozens of methods for the comprehensive utilization of Bayer red mud, but most of them have not reached the industrial level. Therefore, the comprehensive utilization rate of Bayer red mud is the lowest among the three kinds of red mud, and it is hardly used effectively.

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