Development of microstructure of the fly ash aerated concrete in time

Abstract

Calciumhydrosilicate components formed during autoclaving process are highly complex formations, which often blend together mutually and form a variety of intermediate products, from completely amorphous, to the good crystalline phases. For fly ash autoclaved aerated concrete is the situation even more complicated by the fact, that high temperature and fluidized fly ash, as basic silica ingredients, have high variability of the chemical and mineralogical composition. This paper presents the results of the microstructure monitoring and physical and mechanical tests on samples of the fly ash aerated concrete based on high temperature and fluidized fly ashes performed after 2 years of storage in laboratory conditions. The microstructure of aerated concrete is evaluated on the basis of SEM images and mineralogical composition according to X-ray analysis. The changes in compressive strength, density and coefficient of thermal conductivity of the fly ash aerated concrete in time are evaluated.Calciumhydrosilicate components formed during autoclaving process are highly complex formations, which often blend together mutually and form a variety of intermediate products, from completely amorphous, to the good crystalline phases. For fly ash autoclaved aerated concrete is the situation even more complicated by the fact, that high temperature and fluidized fly ash, as basic silica ingredients, have high variability of the chemical and mineralogical composition. This paper presents the results of the microstructure monitoring and physical and mechanical tests on samples of the fly ash aerated concrete based on high temperature and fluidized fly ashes performed after 2 years of storage in laboratory conditions. The microstructure of aerated concrete is evaluated on the basis of SEM images and mineralogical composition according to X-ray analysis. The changes in compressive strength, density and coefficient of thermal conductivity of the fly ash aerated concrete in time are evaluated.