Preparation of bittern-resisting cement used by fly ash

Based on compound cementitious system of clinker containing C4A3S¯ phase, ground fly ash, and granulated blast-furnace slag, a new kind of cement, the Bittern-resisting Cement, is studied for high-bittern environment in the northwest of China. This new material uses class □ fly ash as raw material to produce BRC clinker containing C3S and C4A3S¯ phase, and class □ fly ash as high-activity cement admixture. Experiments show that the setting time of BRC is relatively shorter but the later strength is higher, and the resistance to chemical attack of brines is more excellent than ordinary Portland cement, which is more suitable for engineering construction in saline lakes. By means of XRD, TG-DTA and SEM, the clinker phases and the hydrated products of BRC are studied and the mechanism of corrosion resistance to chemical attack in brines also is examined.