Effects of Aging on Multiscale Mechanistic Properties of Asphalt Binders: Fid-Bau Portal

Effects of Aging on Multiscale Mechanistic Properties of Asphalt Binders

Roy, Sumon / Hossain, Zahid

The aging of asphalt binders is one of the major concerns of highway agencies as it can lead to premature distresses such as fatigue or thermal cracking, which reduces the durability of the asphalt pavements. The purpose of this study is to investigate the aging effect on the asphalt binder’s multiscale mechanistic properties. In this study, macro-level Dynamic Shear Rheometer (DSR) tests were done on the binder samples under different aging environments (unaged, short-term aged, and long-term aged). Additionally, Atomic Force Microscope (AFM)-based techniques were utilized to observe the aging effects on the mechanical properties of asphalt binders at the molecular level. Selected performance grade (PG) binders used in this study were collected from two different crude sources: Canadian (Source 1) and Arabian (Source 2), which were evaluated in the laboratory. As expected, the complex modulus increased due to aging, but the rate of aging was dissimilar between the two sources. The AFM test results showed that the microstructures are noticeably changed or reformed and resulting in increased roughness on the binder surface. The nano-level modulus and adhesion values were also found to be increased due to the aging of the asphalt binders. The findings of this study can help to better understand the effect of aging on the asphalt binder rheology and microscopic properties.