Synergistic effect of combining slag and waste glass on the early age and microstructural properties of cementitious materials

This study investigates the effect of incorporating ground-granulated blast furnace slag (GGBS) on the early-age and microstructural properties of cementitious materials containing waste glass powder (WGP). These industrial waste materials being substitutes for cement content up to 30%. The study employs a mixture design approach for optimizing the composition, using mathematical models to evaluate their effects on the studied properties. Fifteen mixtures were prepared for this investigation. XRD and SEM/EDS analyses are carried out to investigate the structure and composition of the cementitious matrix. Following ASTM C150 standards, the examination reveals that mixes based on GGBS and WGP exhibit extended initial and final setting times. Notably, this study confirms that these delays do not compromise the consistency and soundness of the paste, affirming the positive effects of incorporating these materials as substitutes for cement. Microstructure analyses further show good adhesion between GGBS-WGP and the cementitious binder, indicating that the hydration process leads to the formation of additional calcium silicate hydrate gel, thereby enhancing the strength of the paste. This research contributes to the development of eco-efficient binders that exhibit increased cement replacement ratios, demonstrating qualities that are the same as or better than those found in traditional cement systems.