Effectiveness of Rejuvenators for Asphalt Mixtures with High Reclaimed Asphalt Pavement Content in Cold Climates

Current needs require the use of low environmental impact technologies in construction works. At the same time, the natural deterioration of roads makes maintenance and rehabilitation operations inevitable, with the consequent production and storage (or disposal) of huge quantities of Reclaimed Asphalt Pavement (RAP). Extensive research has thus been conducted and is still ongoing to maximize RAP recycling, trying to minimize the issues related to production and in-service properties, in particular in cold climates. This paper evaluates the feasibility of using large amounts of RAP in asphalt mixtures subjected to cold temperatures. With this aim, mixes were analyzed with different RAP contents (50% and 70%) and prepared with or without the addition of rejuvenator (two types of rejuvenators were selected). A traditional control mixture was also produced for comparison purposes. Dry and wet indirect tensile strength as well as stiffness and resistance to repeated loading properties at low and mid-service temperatures were assessed. Overall, the results showed a similar efficacy of the two rejuvenators in guaranteeing satisfactory mixture performance at low temperatures.