Effect of rejuvenator on asphalt performance based on rheology and surface free energy

This paper studies moisture damage resistance from the perspective of adhesion. The old asphalt in reclaimed asphalt pavement (RAP) is recovered using the extraction method, centrifugal impurity removal and distillation recovery method. Effects of an asphalt rejuvenator on the physical and rheological properties of new and old asphalt are studied. The surface free energy (SFE) parameters of asphalt and aggregate are measured and calculated using the sessile drop and vapour adsorption methods, respectively. The cohesion and adhesive bond energy, and the moisture stability index ER value of asphalt and aggregate, are calculated based on the Good-van Oss-Chaudhury (GvOC) theoretical system. The results show that the addition of an asphalt rejuvenator has a significant recovery effect on the physical and rheological properties of old asphalt. When the content of the asphalt rejuvenator is 4%, it can be restored to the level of new asphalt. When the content of the asphalt rejuvenator is between 3% and 4%, it is similar to that of new asphalt. However, the asphalt rejuvenator has a negative effect on the high-temperature and adhesion properties of new asphalt.