Utilization of circulating fluidized bed fly ash in preparing non-autoclaved aerated concrete production

•NAAC has a substantial advantage in facilitating the manufacturing process.•In our study, steam curing was conducted lower than 100°C for 8–24h after samples being cut.•We used CFA as raw materials for making CFA non-autoclaved aerated concrete CNAAC.•We investigated the effect of preparing parameters of CNAAC on mechanical properties.•The optimal technological parameter for preparing NAAC in laboratory scale was obtained. Circulating fluidized bed combustion (CFBC) fly ash (CFA) is an industrial waste from CFBC boiler of electric power plant, which is not a good supplementary cementitious material for Portland cement and concrete because its expansive feature results in unexpected deterioration of concrete in the last stage. The non-autoclaved aerated concrete (NAAC) was developed using the CFA as main raw materials in this study. To find out the effect of raw materials on the products properties, rheological property of fresh pastes, physical, chemical, mechanical and microstructure analyses were performed. The results show the reasonable dosage of CFA, cement, and lime were 65.5%, 22%, and 10%, respectively. Medium diameter of CFA particle size ranges from 9.6μm to 23.9μm is the most suitable for preparation of NAAC duo to the matching condition between thickening rate of the slurry and the reaction rate of aluminum powder and water. The principal minerals in NAAC are needlelike AFt and floccular C–S–H, be different from autoclaved aerated concrete (AAC).