This paper highlights the aging superiority of asphalt rubber and asphalt rubber hot mixes compared to conventional asphalts and mixes. The paper presents a review of the major studies available in the literature that demonstrated the improved aging resistance of asphalt rubber and asphalt rubber mixes. The paper provides results from standard tests conducted on unaged and laboratory-aged binders to evaluate the effect of rubber modification on the rheological properties of the binders and resistance to aging. Test results pertaining to engineering properties and performance behavior (fatigue cracking, permanent deformation, and low-temperature cracking) of aged and unaged asphalt rubber mixes are also provided for both laboratory-aged and field-aged specimens.
The paper concludes that asphalt rubber hot mix offers an excellent product that surpasses the conventional unmodified mix with regard to long-term performance and long-lasting aging resistance superiority. Finally, the paper presents a few areas where additional work would be needed to quantify the benefits of asphalt rubber aging superiority more effectively and improve damage and performance models to capture these benefits more accurately in pavement design and rehabilitation.