Influence of nano silica on durability properties of concrete

This study focuses on determining water permeability, water absorption, chloride permeability, and compressive strength of nano-silica added concrete. Nano-silica was utilized as a cement replacement material (0-3 wt %) to design and cast two different grade concrete mixes. The microstructure development of concrete was studied using scanning electron microscope images and energy-dispersive X-ray spectroscopy. The results specify that adding 3% nano-silica to concrete enhances its microstructure by creating a denser calcium silicate hydrate gel and lowering calcium hydroxide crystals. After 56 days, the compressive strength of concrete mixes (M 30 and M 40 grade) containing 3% nano-silica was 13.14% and 16.92% greater than the control mix (0% nano-silica). Compressive strength is reasonably high in nano-silica added concrete mixes, but they have low water absorption, water, and chloride permeability. Thus, nano-silica can develop concretes with lower water absorption, water permeability, and chloride permeability.