Abstract:The propoties of cement mortar mixed with fly ash and slag powder under freezing-thawing or wet-dry cycles with salt soaking as well as under both of them were studied.The mass loss ratios,longitudinal relative dynamic elastic modulus,cubic compressive strength and other properties were tested and the optimal ratio was obtained.The results show that the damage to the specimens well be more serious with the increasing of the number of freezing-thawing cycles or wet-dry cycles.The mass loss ratio negatively increases with the increasing of the number of freezing-thawing cycles or wet-dry cycles,while the cubic compressive strength and longitudinal relative dynamic elastic modulus decrease.The behaviors of specimens with mineral admixtures (experimental group) are worse than those without mineral admixtures (control group).The smaller the experimental group's ratio of water to cementation material,the closer the data changing trend of the experimental group and the control group.Under the combined effect of freezing-thawing cycles and wet-dry cycles,the damage to specimens is more serious than that under a single effect,but the changing process is relatively smooth.