Role of barium carbonate and barium silicate nanoparticles in the performance of cement mortar

This study investigates the impact of low-cost barium carbonate and barium silicate nanoparticles (NBC and NBS, respectively) on the performance and phase composition of cement mortar (CM). The results reveal that the individual addition of NBC and NBS causes setting times shortening and mechanical properties increment. Nevertheless, the NBS exhibits the higher efficiency at all addition levels (1, 2, and 3% by weight of cement). The incorporation of NBC results in the consumption of sulfate within cement matrix and the formation of insoluble barite (BaSO4) and calcium monocarboaluminate phases. Although the NBS also represents high efficiency in the uptake of sulfate, the reactive silicate within NBS plays a significant role in the formation of additional calcium silicate hydrate content through the consumption of portlandite (resulted from cement hydration). This could enhance the successful application of cement-NBS mixtures as super sulfate resistant cements.