Abstract: Based on the different research of calcium materials admixture, the optimum proportions of calcium materials were obtained, the action mechanism were also analyzed in the preparation process of autoclaved aerated concrete.The XRD results suggested that the major mineral phases in the AAC product were tobermorite with residue quartz and anhydrite.The examination by scanning electron microscope depicted a waving curved morphology of newly formed crystalline phases, which intertwined into mesh structure and played an important role in the development of products strength.

Key words: Calcium materials, Autoclaved aerated concrete, Iron ore tailings.