Rheological properties of model wax doped asphalt binders

To better understand the effect of three kinds of pure wax in asphalt binder on the rheological properties of asphalt, model asphalts were prepared with eicosane, triacontane, and squalane. Multi-stress creep recovery (MSCR) test, linear amplitude scan (LAS) test, and low-temperature dynamic mechanical test (torsion bar) were employed as the primary performance evaluation methods of high-temperature rutting, medium temperature fatigue, and low-temperature thermoreversible aging of asphalt binder, respectively. The test results showed that at high temperatures, no matter what form of wax existed, it could hurt the rutting resistance of asphalt; however, the branched-chain alkanes reduced this adverse effect. Under medium temperature, triacontane had the most significant negative influence on the fatigue performance of asphalt, while eicosane and squalane improved the fatigue performance of asphalt. Finally, thermoreversible aging was observed in the waxes doped asphalts at low temperatures. The degree of thermoreversible aging mainly relied on temperature, time, and wax structure rather than stress-induced volume change or previous deformation history.