Performance Evaluation and Characterization of Extracted Recycled Asphalt Binder With Rejuvenators

Rejuvenators are used in the asphalt industry to improve the performance and durability of aged binders and facilitate the use of recycled asphalt materials. The purpose of this study was to evaluate the impact of rejuvenator type and dose on the laboratory performance of asphalt binders. For this study, recycled asphalt pavement (RAP) and extracted RAP binder were obtained from an airfield reconstruction project located in Atlantic City, NJ. One petroleum-based (aromatic extract) and three organic-based (corn oil, tall oil, and modified vegetable oil) rejuvenators were evaluated in this study. Each rejuvenator was used at two different rejuvenator doses (6% and 12% by total RAP binder weight) and was aged at three different levels. Performance grade testing, frequency sweep tests, critical temperature differential (DT_c ), and Fourier transform infrared spectroscopy (FTIR) tests were conducted. Results showed that the use of rejuvenators lowered the high and low performance grade of extracted RAP binders, in particular organic-based rejuvenators had a greater impact on the performance grade. DT_c was also improved through the use of rejuvenators. In fact, the extracted RAP binder exceeded the high severity DT_c threshold (25°C), whereas the rejuvenated RAP binders improved DT_c to values greater than the low severity threshold (22.5°C). Similar findings were observed from the Glover-Rowe parameter as well, in which rejuvenated RAP binders improved the cracking resistance of the extracted RAP binder. When assessing the aging susceptibility, modified vegetable oil and corn oil rejuvenators showed the smallest change in performance between aging levels.