Asphalt modification using nano-materials and polymers composite considering high and low temperature performance

Nano-materials have a great potent ial as modifiers for enhancing performance of base asphalt binder. However, existing studies in the literature focus on the improvement of high-temperature performance of base asphalt binder, whereas the low-temperature performance of base asphalt binder is overlooked. Studies have shown that nano-materials will even weaken the low-temperature performance of base asphalt binder. To address this issue, nano-materials and polymers as composite modifiers are studied to improve base asphalt performance at both high temperature and low temperature. Nano-materials and polymers were screened and selected according to conventional performance indicator of asphalt binder, including softening point, ductility at 5 °C and viscosity at 60 °C. Optimal formulas of composite modifiers were determined using orthogonal experiment design and range analysis. SHRP tests including RTFOT, DSR and BBR tests were conducted to better evaluate the anti-aging, high-temperature performance and low temperature performance (i.e., crack resistance and water stability) of the proposed optimal composite modified asphalt binder against performances of 5%SBS modified asphalt binder and AH-70 base asphalt binder, showing an improved pavement performance.