Nanoleveled Mechanism of Rejuvenated Aged Asphalt Binders by Different Rejuvenated Agents

摘要

The purpose of this paper is to study the microleveled rejuvenating effects of different rejuvenating agents on aged asphalt binders. In this study, an original asphalt binder (Shuanglong) with a grade of Pen70 was aged through an accelerated aging process specified by a strategic highway research program (SHRP). Two types of rejuvenating agents (one virgin asphalt binder and another petroleum product named HNCCY-1) were used to rejuvenate the aged asphalt binder at different concentrations. An atomic force microscopy (AFM) was used to study the microleveled properties of the rejuvenated aged asphalt binders, whereas the dynamic shear rheometer (DSR) was for rheological properties. The results showed that: (1) the number of bee structures increased, but their size decreased in the topographies of height or adhesion of the rejuvenated asphalt binders as the concentration of both the rejuvenating agents increased; (2) the roughness indexes gradually decreased and approached those of the original asphalt binder; (3) the diameter and threshold height decreased; and (4) the Young's modulus and reduced modulus became smaller.