ABSTRACT
Increased costs of virgin asphalt pavement materials have encouraged transportation agencies to allow higher quantities of reclaimed asphalt pavement (RAP) in their recycled asphalt mix design if performance can be maintained. Recycling agents or rejuvenators are organic materials used to reduce the stiffness and brittleness of RAP binders and make recycled mixtures less prone to cracking. Recycling agents can facilitate the use of higher quantities of RAP; however, there is limited understanding on their effect on the homogeneity of the final blend of virgin and recycled binders and recycling agent. This study utilized Atomic Force Microscopy (AFM) to assess the effect of recycling agents on the homogeneity of different blends of virgin and RAP binders. AFM results revealed that the addition of recycling agents improved the homogeneity of blends at unaged and short-term aging conditions; however, this effect diminished after long-term aging.
