Evaluation Of Physical-Rheological Properties of Nano Titanium Dioxide Modified Asphalt Binder and Rutting Resistance of Modified Mixture

Most of the pavement distress in warmer regions is due to rutting and moisture damage. As a result, additives are now required to enhance the properties of asphalt binders and mixtures. The influence of nano titanium dioxide (TiO2) modification on the physical and rheological characteristics of the asphalt binder, as well as the rutting performance of Hot Mix Asphalt (HMA), was investigated in this study. The modified binders were evaluated by Bending Beam Rheometer (BBR), the Dynamic Shear Rheometer (DSR) Pressure Aging Vessel (PAV), Rolling Thin Film Oven Test (RTFOT), and Multiple Stress Creep Recovery (MSCR) test. After aging the modified binder over short and long periods, potential rutting was evaluated. Non-recoverable compliance (Jnr) was assessed for early aging. The MSCR and the Superpave system were used to evaluate the performance grade of binders. The stiffness of modified binders was also measured at low temperatures. Rutting resistance was evaluated for HMA specimens containing nano TiO2 by the Hamburg Wheel Track Device (HWTD). Several percentages of nano TiO2 (1.5%, 3.5%, 5.5%, and 9%) were used to enhance the characteristics of 60-70 asphalt binder. The results revealed that nano TiO2-modified binders enhanced the rheological and physical properties of unaged and aged asphalt binders. The findings also showed that nano-TiO2 increased the rutting resistance of asphalt mixtures. The statistical analysis indicated that the nano TiO2 modification significantly improved all tested properties of the base asphalt binder, however, the stiffness and Jnr difference were found insignificantly influenced by the incorporation of the nano TiO2.