SUPERIOR AGING CHARACTERISTICS OF ASPHALT RUBBER

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.