Strength deterioration of nano-silica contained in ordinary Portland cement concretes in aggressive sulfate environments

Abstract

This investigation presents the effect of durability of concrete in aggressive conditions and loss of compressive strength measurements for concrete incorporating 0%, 5% and 10% powdered nano-silica (NS). The important factor in this investigation is air curing, water curing, the kind of the sulfate exposure regions (continuous and drying-immersion cyclic exposures). For this investigation, w/cm (water to cementitious materials) proportion is 0.4, and 0.5. Up to 365 days the decrease in the compressive strength of concrete was examined for the aggressive sulfate conditions. In these concrete specimens, three groups were kept up. In the control assessment of compressive strength reduction, tap water was used, and this was kept up as the first group. Under continuous and cyclic exposures, 10% Na2SO4 was used as a part of alternate groups and the preparation submerged up to 365 days’ time duration. All the blends subjected to the compressive test, and durability studies, such as sorptivity, water absorption, and chloride penetration test. The outcome demonstrates the protection of cement against sulfate attack expanded by incorporating NS types of cement. The advantage of incorporating 5%, 10% NS to the densifier cement concrete, expands strength and reduces permeability.