ABSTRACT
ABSTRACT: The effect of nano-SiO2 on the mechanical strengths of concrete and corrosion rate of embedded steel under different mixing and curing conditions was investigated. Twelve types of concrete mixes were made by altering the content of nano-SiO2 (1%, 3% and 5% by weight of cement) and type of mixing and curing water. Potable and saline (3.5% NaCl) water were used for mixing and curing for different concrete mixes. The mechanical strengths were found to increase for specimens mixed and cured in saline water at the early ages, while, a reduction in the respective strengths was observed for later ages. However, it was observed that the addition of nano-SiO2 increases the strength of concrete and reduces the corrosion rate of embedded steel as compared to reference mixes. This is because the nano-SiO2 fills the tiny voids between the hydration products and thus, reduces porosity, which leads to a compact structure of concrete.
