Document Type : Research Paper


Highway and Transportation Engineering Department, College of Engineering, Mustansiriyah University, Baghdad 10045, Iraq.



Incorporating crumbed rubber into asphalt binder or asphalt concrete mixes has become increasingly common in recent years. Researchers have looked into how well this additive can improve both the modified bitumen and the modified asphalt mix. With the growing usage of rubber crumb modifiers in asphalt mixtures, the significance of certain asphalt qualities has been recognized. This has opened up more opportunities for a thorough examination of their rheological and physical properties. The asphalt-rubber binder's performance was often impacted by the amount of crumb rubber and the blending circumstances. In this study, a new method, the Steam Aging Technique (SAT), was utilized to study the attributes of the rubber-enhanced bitumen, which was aged throughout Bitumen’s service. The primary goal of this research was to investigate the influence of traditional aging methods compared to the steam aging method, and the possibility of using the latter as an alternative test to traditional methods. Overall, physical test results showed notable increases in softening point and rotational viscosity and a decrease in penetration value for vapor-aged bitumen contrasted to non-aged bitumen. This research used a dynamic shear rheometer (DSR) and a temperature sweep test (TS) method to study rutting under control strain mode. The effectiveness of the use of steam aging has been observed and the possibility of using it as an alternative to the conventional aging methods available was investigated. It was found that there was a great convergence in the results extracted from the steam aging device with an addition rate of 5, 10, and 15% and an aging time of 45 minutes with the results extracted from the rotary kiln device, except for the 20% addition rate, which gave a difference in values.