Mechanical, expansion and rheological properties of circulating fluidized bed fly ash based ecological cement: A critical review

Circulating fluidized bed fly ash (CFBFA) is a solid waste of circulating fluidized bed (CFB) boilers in power plants, and the storage of CFBFA is becoming an increasingly environmental problem. Various methods have been developed to improve the performance of CFBFA based ecological cement (CEC). In this work, the physicochemical properties of CFBFA were introduced, and the recent research progress on the mechanical, expansion and rheological properties of CEC were extensively reviewed. The active silica-alumina component and SO3 inside CFBFA were beneficial to the development of CEC strength. In addition, the expansion rate of CEC was significantly increased by the f-CaO in CFBFA. The rheological properties of CEC are controlled by regulating CFBFA particle size. The challenge for f-CaO in CFBFA to compensate for cement volume shrinkage is proposed. Moreover, the environmental conservation, durability, and economy of CEC should be valued in the future research.