Effect of bio-rejuvenator on recycled porous asphalt mixes

The significant use of porous asphalt (PA) in many countries makes incorporating reclaimed asphalt pavement (RAP) from PA into a new PA mix a crucial activity. This paper investigates the effect of different percentages of a bio-rejuvenator (i.e. 0%, 5%, 10%, 15%, and 20%) on volumetrics and mechanical properties of PA mixes containing 20% PA RAP. Ravelling resistance, moisture sensitivity, resilient modulus, and dynamic modulus (DM) were assessed. The mixes’ volumetric properties were driven by the RAP aggregate, not by the level of rejuvenation. The increase in the rejuvenation dosage resulted in improved PA performance. A balanced approach for selecting the optimum rejuvenation level was proposed. The DM results were corroborated with findings from the previously published research using atomic force microscopy (AFM), suggesting that AFM can predict the optimum level of rejuvenation for RAP and provide insights into the rejuvenation mechanisms at the nanoscale.