Performance enhancement of stone mastic asphalt using nano-TiO₂: A combined experimental and finite element study

This study examines the impact of nano titanium dioxide (nano-TiO₂) modification on the mechanical behaviours of Stone Mastic Asphalt (SMA), focusing on two critical performance indicators: resilient modulus and dynamic creep. Using Finite Element Analysis (FEA), simulations were conducted on SMA samples containing 0%, 2%, 3%, and 4% nano-TiO₂ to evaluate stress distribution and deformation characteristics under load. At 25 °C, the 3% mixture had the highest displayed resilient modulus at all three pulse repetition periods. In the 40 °C dynamic-creep plot, the 3% mixture showed lower accumulated strain than the 2% and 4% mixtures, while the unmodified mixture had the lowest terminal strain. To reinforce these findings, laboratory tests were conducted and paired with regression analysis, which further validated the enhanced performance of the modified mixtures. The outcomes highlight the potential of nano-TiO₂ as an effective additive for producing more durable and deformation-resistant SMA, offering practical insights for sustainable pavement design.