Characterization of solid waste-based cementitious materials: Effects of curing conditions, temperature, and duration

The extensive accumulation of flue gas desulfurization ash (FGDA) and carbide slag (CS) has led to significant environmental pollution. In this study, FGDA, CS, and blast furnace slag (BFS) are used to prepare solid waste-based cementitious materials (SWBCMs). This study investigates the impact of CS dosage and various curing methods, including curing conditions, temperature, and duration, on the compressive strength, hydration products, and microstructure of SWBCM. The results indicate that increasing the CS content from 2% to 10% significantly improves the 3- and 28-day compressive strengths of SWBCM. At standard temperature (20 ± 2 °C), SWBCM exhibits the highest early and late compressive strengths under steam curing. The SWBCM cured at 60 °C for 12 h achieves the highest 3-day compressive strengths. Moreover, excessive heat curing (due to excessive temperature or curing time) leads to shrinkage cracks that reduce the compressive strength of SWBCM. Mineralogical analyses and microstructural characterization show that the CS content and curing methods affect the amount and distribution of the hydration products and the microstructure, which, in turn, affects the compressive strength of the SWBCM. This study can facilitate the development of low-carbon cementitious materials and the practical application of SWBCM.