Comprehensive analysis of linear viscoelastic (LVE), non-linear viscoelastic (NLVE), and chemical parameters of asphalt binders from multiple aging perspectives

Aging of asphalt binder is a main cause of damage in asphalt mixture during the long-term service. However, the correlations between decrease of rheological properties and fatigue damage at microscale are not clear especially for highly-aged materials. In this work, diverse rheological parameters have been utilized to characterize the linear viscoelastic (LVE) and non-linear viscoelastic (NLVE) behavior of asphalt binders. Microscale structure migration was correlated with rheological properties characterized by the optimal Glover-Rowe parameter (GRP) after aging ratio comparison. Small molecules were coalesced into long carbon-chain structures while internal chemical bonds produced during aging. Specific functional groups are oxidized into oxides such as sulfoxides. Sf and Nf from simplified-viscoelastic continuum damage (S-VECD) model were gradually reduced by conversion of micro-molecules. The internal micromolecular polymerization and oxidation caused by aging will potentially lead to the weakening of rheological properties. The objectives of the research are to obtain typical LVE and NLVE parameters via comparing aging sensibility, and link the internal microscale structure to rheological properties.