Previous and present investigations on the components, microstructure and main properties of autoclaved aerated concrete – A review

•AAC is widely used due to its excellent thermal insulation property and easy availability.•Components, microstructure and main properties of AAC were comprehensively and thoroughly reviewed.•Future research suggestions were presented based on the overview. Autoclaved aerated concrete (AAC) has being attracted more and more attention as its excellent thermal insulation and environmentally friendly characteristics. The properties of AAC depend on components, microstructure and external environment (e.g. relative humidity and CO2). Previous investigations systematically demonstrate the evolution of microstructure and variation of physical properties with different kinds of binders and curing conditions, while present researches enhance the understanding of interaction among comprehensive factors. This paper mainly refines the literatures on AAC in terms of constituent materials (especially industrial wastes and additives), preparation, microstructure and main properties (density, dry shrinkage, hygric property, mechanical properties, anisotropy, thermal insulation and durability). Based on the review, urgent needs should be made in efforts as follows: (i) compatibility between the stiffness rate of AAC slurry and the gas-generation rate; (ii) relationship between the connectivity of pores and thermal insulation; (iii) measures to better the durability.