Investigation of the Effect of Crumb Rubber Powder and Warm Additives on Moisture Resistance of SMA Mixtures

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