AASHTO R 28-21

This standard practice covers the accelerated aging (oxidation) of asphalt binders by means of pressurized air and elevated temperature. The practice is intended to simulate in-service oxidative aging of asphalt binders and is intended for use with residue from AASHTO T 240 (RTFOT).

The aging of asphalt binders during service is affected by mixture-associated variables such as the volumetric proportions of the mix, permeability of the mix, properties of the aggregates, and possibly other factors. This practice is intended to provide an evaluation of the relative resistance of different asphalt binders to oxidative aging at selected temperatures and cannot account for mixture variables.