Internal aging indexes to characterize the aging behavior of two bio-rejuvenated asphalts.

Abstract Profound progress has been made in bio-rejuvenators to enhance aged asphalt's low temperature performance and reduce its high temperature viscosity. However, limitation still exists in the knowledge how long service life of rejuvenated asphalt is and whether regeneration is effective since aging behavior of rejuvenated asphalt is neglected. Furthermore, aging evaluation is based on different tests dependent on temperature, which may lead to various results. This study aims to evaluate the aging behavior of bio-rejuvenated Pen70 and SBS modified asphalts using internal aging indexes that characterize the physical property. Original Pen70 and SBS asphalts under identical aging conditions were set as the control group. Fourier transform infrared spectroscopy test (FTIR) was conducted to quantify aging extent through oxidation aging functional groups. Activation energy was achieved through rotational viscometer (RV). Dynamic shear modulus was acquired through dynamic shear rheological test (DSR) and characterized by two springs, two parabolic elements, and one dashpot (2S2P1D) model. For both Pen70 and SBS, the two potential aging indexes related with activation energy and viscosity of dashpot separately were found linearly correlated with related chemical aging functional groups. Through comparison, it indicates that bio-rejuvenation was a process of physical blending. It couldn't restore the crosslinking structures of SBS polymers. Besides, the physical property of bio-rejuvenated Pen70 degenerated faster, while that of bio-rejuvenated SBS stayed stable. A benefit period was proposed for the rejuvenation of Pen70 while the rejuvenation of SBS was not bound by time. Further work is needed to validate findings in the present study. Graphical abstract Image 10385 [ABSTRACT FROM AUTHOR]