Possibility to optimize hydrothermal conditions for the production of autoclaved aerated concrete using rice husk ash as the silica raw material

Rice husk ash (RHA) was utilized as a substitute for quartz sand to produce autoclaved aerated concrete (AAC). Different autoclaving temperatures in the range of 152 °C to 192 °C with an autoclaving duration of 6 h were applied. The compressive strength and phase formation were studied. Ordinary AAC samples which contained quartz sand exhibited their most favorable properties at the autoclaving temperature of T = 192 °C. However, this temperature was 165 °C when RHA was used as the silica raw material in AAC.