Abstract：This study investigated the utilization of CO2-treated recycled concrete powder and recycled brick powder composite as a substitute for slag in the alkali-activated slag (AAS)mortar. The impacts of varying substitution levels of carbonated recycled composite powder (CCP)on the setting time, mechanical strength, and water absorption characteristics of AAS mortar were investigated. The results reveal that a 10% substitution rate of CCP yields the optimal compressive strength, surpassing that of untreated RBP by 19%. The main component of CCP is CaCO3, which has low solubility in alkaline environments andconsequently retards the setting time of AAS paste. Compared to RCP, the incorporation of CCP results in a further increase in the water absorption rate of AAS mortar. Furthermore, CCP has better ecological and economic benefits in AAS mortar.
2024, Vol. 0 
