Published on 26 October 2019
When replacing expensive and scarce cement for the preparation of concrete mixtures, one of the promising alternative binders is fly ash which is formed when coal is burned at thermal power plants. The feasibility of such a replacement depends on the results of studies of the effect of the number of additives of complex binders of different types to cement on the strength of concrete mixtures. The aim of the research was to determine the dependence of concrete strength on cement consumption with fly ash additives, which allows to evaluate the effect of reducing cement consumption while maintaining the quality of concrete. As part of the research, the efficiency of the mixing operation of concrete mixtures components, which significantly affects the physical and mechanical properties of concrete products, was evaluated. So, it is determined that when the intense components mixing of concrete mix in the disintegrator concrete strength increases 1,5-2 and more times. It is established that the optimal mode for mixing the concrete mixture in the disintegrator is the relative velocity of particle collision of 30 - 40 m/s, and a further increase in this velocity is impractical. The results of determining the quantitative parameters of the dependence between the flow rate of cement with fly ash additives and the strength of the concrete mixture are the basis for optimizing the ratio of binder and inert components with a decrease in cement consumption while maintaining the desired quality of concrete. The quantitative values of optimal speeds of mixing are obtained experimentally by comparing alternatives by mixing manually or in the disintegrator. Partial replacement of cement with alternative substances is a promising direction to reduce the deficit of binders not only to ensure the volume of preparation of concrete, but also to reduce the load on the environment. With the intense components mixing in the disintegrator concrete strength increases 1,5-2 and more times. The results of the study are of interest in the manufacture of concrete to fill technological voids formed by the excavation of minerals in the process of underground mining. The proposed technology is a reserve for obtaining economic effect in the modernization of mining and related industries.
Tags: измельчение, активация, цемент, зола-унос, бетонная смесь, дезинтегратор.
ISSN 1998-4502 (Print) ISSN 2499-975Х (Online)