A Comparative Study of the Impact of Nano-TiO2 and Nano-silica on the Durability of Concretes Cured at Different Temperatures

Abstract

A comparative study was conducted to evaluate the impact of diffident types of nanoparticles, specifically nano-TiO₂ and two types of proprietary nano-silica, on the mechanical and durability properties of concretes cured at varying temperatures. The study involved the assessment of compressive and flexural strengths of concretes with and without the incorporation of nanoparticles. Resistivity measurements were also performed to assess the influence of nanoparticles on pore connectivity. Additionally, the total pore volume of concretes with and without the addition of nanoparticles was also measured and water absorption tests were conducted to explore the impact of nanoparticles on concrete permeability. The study further evaluated the damage incurred by concretes exposed to freeze-thaw cycles and deicers, comparing materials with and without nanoparticles. The findings indicated that all types of nanoparticles enhanced concrete’s mechanical properties and durability. Specifically, they significantly reduced total porosity, pore connectivity, and water permeability, with these improvements being more pronounced effect in concretes cured at low temperatures. In terms of increasing the scaling resistance, the optimal dosage of nano-TiO₂ was determined to be 0.5%. However, both the 0.5% and 1.0% dosages contributed to improved mechanical strength of concrete. Finally, a synergistic effect was observed when both types of nano-silica were combined, leading to improvements in the overall performance of the concrete.