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The paper deals with the structure and phase composition of non-autoclave aerated concrete with a density of 600-800 kg m-3 using ferrosilicon as a gasifier. The conditions of formation of porous structure of aerated concrete and preparation of calcium hydrosilicates were considered. Phase composition of the samples was investigated by means of X-ray phase analysis and differential thermal analysis. Analysis of X-ray patterns showed that the test samples contained tobermorite 11.3 A (5CaO-6SiO2-5.5H2O), xonotlite (6CaO-6SiO2-H2O) and a-dicalcium silicate hydrate (2CaO-SiO2-H2O) as a binder. It was established that there is an increase in the content of hydrosilicate phases with an increase in the content of gasifier in the vast majority of cases. The obtained data were confirmed by the results of differential thermal analysis. [ABSTRACT FROM AUTHOR]

The possibilities of optimization of cutting technology for the production of autoclaved aerated concrete and the use of low-clinker binders in it are investigated. Taking into account the price factor, energy-ecological trends in the development of the industry of building wall and heat-insulating materials, autoclaved aerated concrete has significant prospects for the development of production. With the transition to the production of autoclaved aerated concrete of lower density, on the one hand, the total material consumption of production decreases, and on the other, the specific costs of the binder (cement) per unit mass of aerated concrete increase. The research was aimed at implementing a number of technological solutions. They imply a decrease in the energy intensity of production by minimizing the clinker component in the raw mix and an intensification of the production process in order to increase the coefficient of the structural quality of the material, as well as the possibility of mass production of low-density aerated concrete. Reducing the clinker component by replacing it with active mineral additives, blast-furnace granular slag, under the conditions of cutting technology, is possible provided that the problem of accelerating the plastic strength gain of aerated concrete raw material at the stage of formation of its macrostructure is solved. It has been established that the implementation of forced synthesis of ettringite at the stage of formation of aerated concrete mixture with a high W/T ratio reduces the time of pre-autoclave holding of the raw massif. This allows the use of mineral additives and enhances the strength of the final product. Replacing 10–15 % of cement with the GBFS addition in the composition of the aerated concrete mixture in the presence of an additional content of gypsum stone of 5–10 % in the composition of sand slime provides an intensive increase in the plastic strength of the raw material before cutting it into products and high strength of the final product [ABSTRACT FROM AUTHOR]