Physicochemical processes during solidification and the peculiarities of structure formation in aerated concretes using metallic silicon as a gas generator

The results of research on the structure and phase composition of non-autoclaved aerated concrete with a density of 550–750 kg/m3 using metallic silicon as a gas generator are presented. The peculiarities of the structure formation of aerated concrete products and the mineralogical composition of their hydration products were investigated. It was established that increasing the content of metallic silicon in aerated concrete leads to an increase in the pore space of the compositions. The results of diffractometric and thermal analysis methods for establishing the phase composition of aerated concrete compositions with metallic silicon as a gas generator are also presented. Analysis of XRD patterns and derivatograms showed that the aerated concrete samples under investigation contain a binder component, obermorite (5CaO6SiO25.5H2O); xonotlite (6CaO6SiO2H2O); -dicalcium silicate hydrate (2CaOSiO2H2O); and hillebrandite (2CaOSiO21.17H2O). It was established that increasing the amount of metallic silicon as a gas generator stimulates an increase in the content of hydrated phases in aerated concrete compositions.