This study aims to improve the performance of alkali-activated slag recycled mortars (AASRMs) by incorporating pre-wetted recycled fine aggregates (RFAs). RFAs with various substitution rates (50 wt% and 100 wt%) and humidity states including air-dried (AD) and saturated surface-dried (SSD) were used to investigate the workability, mechanical properties, drying shrinkage, and micro-morphology of AASRMs. Moreover, life-cycle cost (LCC) and environmental impacts of AASRMs during the raw materials and production phases were comprehensively evaluated. The results showed that, with the increase in RFA contents, the workability, mechanical properties, and drying shrinkage of AASRM deteriorated. However, pre-wetted RFAs significantly enhanced mechanical properties and dry shrinkage resistance of AASRCs. Compared to mortar with 50 wt% AD-RFAs, the specimen with 50 wt% SSD-RFAs exhibited 23.8% higher 14-day compressive strength, 17.6% greater 14-day flexural strength, and 9.7% lower 14-day drying shrinkage. Microstructural analysis revealed that pre-wetted RFAs provided an internal curing effect, promoting hydration and improving the interfacial transition zone between the RFA and the matrix. In addition, the incorporation of RFA led to a reduction in LCC, while a slight increase in environmental performance across all impact categories for AASRMs. This study provides an effective method to improve the mechanical performance and shrinkage resistance of AASRMs, facilitating their practical application.
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