Rheological properties and thermoreversible aging in SEAM modified asphalt binder

In order to better understand the rheological properties and low -temperature thermoreversible aging performance in sulfur modified asphalt (SMA), sulfur -extended asphalt modifier (SEAM) as a modifier is added to base asphalt binder. Incremental repeated -load permanent deformation (iRLPD) test, frequency sweep test, linear amplitude sweep (LAS) test, torsion bar (TB) test, confocal laser scanning microscopy (CLSM) test are selected. The results show that SEAM can improve the high -temperature, medium -temperature and low -temperature properties of asphalt binder in different degrees. In addition, when the SEAM added amount is 35 %, the optimal performance temperature of SEAM modified asphalt binder is medium and low temperature, but not the high -temperature. The rheological properties of SEAM modified asphalt binder are related to the phase state of sulfur. Increasing the dosage of SEAM and extending the pressure aging time may lead to sulfur crystallization, but the effects of both are not equal. During the long-term storage of SEAM asphalt binder at constant temperature, the phase separation between SEAM and base asphalt binder will occur to different degrees, which may be a cause of thermoreversible aging.