Influence of nano-TiO₂ on the chloride diffusivity of concrete

In this research, the benefit of nano-TiO2 concrete over pure concrete in resisting the impacts of chloride diffusion was investigated. An increasing accelerative effect the chloride diffusion was experimentally discovered, which coincided with the movement in the exposed concrete surface caused by diffusion and the damage in concrete microstructure caused by chloride salt accumulation. The “time lag” and “equivalent time” between diffusion and migration tests were used to calculate the steady and non-steady-state chloride diffusion coefficients. Concrete containing 2% nano-TiO2 in the weight of cement demonstrated improved impermeability when compared to pure concrete, owing to improvements in microstructure and porosity. In comparison to pure concrete, the concrete containing nano-TiO2 had a superior performance in resisting the effects of chloride diffusion. Because of its superfine particle size distribution and “filler” effect, nano-TiO2 appeared to assure decreased chloride diffusion in the investigated mixes, test findings revealed that adding supplemental cementitious elements to mortar enhanced its resistance to chloride penetration.