Investigation on the Influence of Preparation Processes on the Performance of SBS-Modified Rejuvenated Asphalt

Polymer-modified asphalt technology can significantly improve the durability of a rejuvenated asphalt pavement and the utilization rate of a reclaimed asphalt pavement. However, different modification and regeneration processes may have a substantial impact on the performance of the modified rejuvenated asphalt (MRA) binder. Therefore, it is necessary to investigate the effects of various preparation processes on the performance of MRA. In this paper, three types of MRA were prepared by using different processes: regeneration before modification (RBMA), modification before regeneration (MBRA), and simultaneous regeneration and modification (SRMA). Styrene–butadiene-styrene copolymer-modified asphalt (SBSMA) was used as a control. The effects of modification and regeneration sequences on the conventional physical properties, storage stability, high- and low-temperature rheological characteristics, repetitive creep recovery performance, and anti-fatigue capability of MRA were studied. The results indicate that RBMA and SRMA exhibit superior low-temperature ductility compared to SBSMA, while the physical properties of MBRA deteriorated due to aging during the modification process. Segregation tests indicated that the storage stability of all MRA met usage requirements, although zero shear viscosity analysis revealed that MBRA had the worst storage stability. The clear plateau in the phase angle curve suggests that a superior network structure can form in the different MRA. Although aging during the modification process deteriorates the rheological properties of MBRA, its resistance to permanent deformation and fatigue is significantly improved. RBMA exhibits an excellent low-temperature performance but poor durability. SRMA properties are closest to those of SBSMA, indicating that simultaneous regeneration and modification can contribute significantly to the properties of rejuvenated asphalt.