Effect of different lithological stone powders on properties of alkali-activated slag

This article studies the diverse effects of lithological on the properties of alkali-activated slag systems by blending different stone powders - limestone (LP), dolomite (DP), quartz (QP), and magnesite (MP). The physical and chemical properties of the raw materials were first analysed, followed by the investigation of reaction kinetics, resulting products, and microstructure. Rheology, strength, and shrinkage were then evaluated. Results indicate that increased LP and DP content improves flowability due to their particle size, while QP has limited effect. All stone powders reduce the degree of reaction, although the stronger affinity of LP and DP for Ca2+ promotes the formation of more reaction products. Microstructural analysis highlights superior bonding of LP and DP to the paste, as evidenced by the lower macro-scale strength loss at low mixing ratios. DP can also mitigate drying shrinkage, whereas MP has the most adverse effect due to its highest capillary pore proportion.