Nanoengineered Cement Mortar: Effects of Nanosilica Particle Size and Water-to-Binder Ratio on Mechanical and Durability Performance

This study investigates the effects of nanosilica (NS) particle sizes and water-to-binder (W/B) ratios on the compressive strength, microstructure, sulfate resistance, and acid resistance of cement mortar. NS particles with diameters of 12, 20, and 40 nm were incorporated at 9% replacement levels and tested at W/B ratios of 0.65, 0.75, and 0.85. The results showed that the 40 nm NS particles, at a 9% replacement, provided the highest compressive strength and resistance to both sulfate and acid attacks, particularly at a W/B ratio of 0.65. The study also found that NS enhances the microstructure and pozzolanic reactions of cement mortar more effectively than silica fume. The use of larger NS particles (40 nm) resulted in improved overall performance, with reduced porosity and increased mechanical strength. These findings highlight the role of NS in enhancing the strength and long-term durability of cement mortar under multiple aggressive environments, providing practical insights beyond conventional short-term studies.