The current research is conducted to assess the effects of Nano-Al₂O₃-particles on the storage stability and high-temperature performance of polymer-modified bitumen (PMB). Nano-Al₂O₃-particles were mixed with PMB in five different contents. The high-temperature performance of obtained bitumen was evaluated by using the storage stability, viscosity and MSCR tests. The results of tests showed that Nano-Al₂O₃-particles improved the storage stability of PMB. Addition of Nano-Al₂O₃-particles into PMB was accompanied by the increase of viscosity. Based on the results of MSCR test, Nano-Al₂O₃-particles remarkably improved high-temperature properties of SBS polymer-modified bitumen. In addition, it was found that incorporation of 1.2% Nano-Al₂O₃-particles into PMB showed a good potential to improve the high-temperature performance of PMB.

Stone matrix asphalt (SMA) mixtures are one of the most resistant types of asphalt mixtures known to date that the bulk load is borne by the aggregate skeleton. In this research, the effect of crumb rubber powder (CRP), Vestenamer polymer, and warm additives, including Sasobit, ZycoTherm, and a porous and warm mix asphalt (PAWMA), was investigated on the moisture resistance of SMA mixtures. A segregation test was performed to determine the tendency of the polymer to separate from modified polymer bitumen under storage conditions. Also, a drain down sensitivity test was conducted to explore the bleeding phenomena and drain down of SMA mixtures. Finally, a boiling water test, as well as an indirect tensile strength (ITS) test, was applied to examine the sensitivity of mixtures to moisture. The segregation test results indicated that by the use of Vestenamer polymer, a conventional (low speed) mixer can be used instead of using a high‐speed mixer, and this will be very important in the cost of rubber bitumen production. The drain down test results showed that cellulose fibers prevented the bitumen bleeding of SMA mixtures. Also, the results of the boiling water test indicated that CRP samples containing ZycoTherm had the highest moisture resistance compared to the other warm additives. Among various mixtures, 8% CRP‐modified samples containing ZycoTherm resulted in the lowest amount of stripping in SMA mixtures, even more than the base sample. The ITS test results illustrated that the use of CRP, Vestenamer polymer, and warm additives had a significant effect on the ITS amounts of mixtures. Moreover, the samples containing ZycoTherm had the highest tensile strength ratio (TSR) compared to the other SMA samples.