Comparative evaluation of two rejuvenator agents for asphalt concretes containing high percentages of RAP: a laboratory investigation and analysis

The utilization of Reclaimed Asphalt Pavement (RAP) in the creation of new hot mixtures is steadily growing due to its economic and environmental advantages. To maximize the advantages of recycling reclaimed asphalt, it becomes essential to incorporate a higher proportion of RAP in bituminous mixtures. This goal can be realized exclusively through the rejuvenation of the aging asphalt binder with rejuvenator agents. This thesis investigates the performance of a newly established rejuvenator agent and an upgraded version of it, compared to a well-known commercial rejuvenator product in the Hot Mix Asphalts containing 50% RAP inside. Four distinct mixtures were prepared, containing different rejuvenator agents and dosages, and have undergone mechanical characterization tests. The research involves a comprehensive assessment of key properties, such as indirect tensile strength (ITS), water sensitivity test (ITSR), stiffness modulus across various temperatures and conditions, and fatigue life performance Despite displaying promising results in fatigue life in the low strain levels for the experimental rejuvenator, the findings suggest that the experimental rejuvenator has a lower effect on the aged stiff binder to improve its performance in comparison to commercial rejuvenator. Also, the experimental rejuvenator exhibited limitations in enhancing the overall performance of the asphalt mixtures, particularly at higher strain levels.