摘要

The use of rejuvenators to restore the properties of reclaimed asphalt pavement (RAP) binders is gaining widespread interest mainly due to its ability to lower the binders' stiffness and enhance their low temperature resistance. The effect that several rejuvenators have on the rheological properties of the modified binders is well-characterized. However, the nature of the interaction between the rejuvenator and the base binder is still not clearly understood. In this research, a rejuvenator made from soybean oil is blended at 6% dosage with an extracted RAP binder. The durability of the modified binder is assessed using laboratory simulated short-term and long-term aging. The performance grade and rheological properties of the modified binder are determined at different stages of aging. Pyrolysis gas chromatography- mass spectrometry (Pyrolysis/GC-MS) is used to probe the chemical composition of the rejuvenator and the chemical stability of the rejuvenator with aging is investigated. The unaged and PAV-aged modified binder are studied using pyrolysis followed by GC-MS, to examine the nature of the chemical interaction between the rejuvenator and the binder, both before and after aging. Pyrolysis is used to thermally desorb the rejuvenator before it is being cryotrapped using liquid nitrogen. The cryotrapped evolved gases are then analyzed using GC-MS. The rheological testing shows that the rejuvenated RAP binder has lower stiffness, higher phase angle and significantly improved fatigue resistance. The pyrolysis/GC-MS results reveal that the rejuvenator is undergoing changes during aging as it interacts with the base binder.

  • 出版日期2018-2