Exploring the Influence of Asphaltenes on Rheology and Aging Characteristics of Asphalt Binders

ABSTRACT Asphalt pavement, crucial for road infrastructure in Northern America, faces challenges like rutting, reduced elasticity, and aging in binders, necessitating sustainable solutions. This study explores the potential of asphaltenes, a by-product of Alberta oil sands, as an additive to enhance key properties of asphalt binders, such as rutting resistance, elasticity, and aging characteristics, through multiple stress creep recovery (MSCR) and frequency sweep (FS) tests on two distinct binder types. Binders, both neat and modified with an optimum asphaltenes concentration of 12 % (by weight of binder), underwent MSCR and FS tests. The MSCR test results revealed that asphaltenes-modified binders had reduced nonrecoverable creep compliance (Jnr) that met requirements for extremely heavy traffic conditions (>30 million equivalent single axle loads) with Jnr values being lower than 0.5 kPa−1. Stress sensitivity was notably reduced, which emphasized the stabilizing effect of asphaltenes. The FS test results showed notable enhancements in stiffness, with 497–546 % increased complex shear modulus, up to seven times higher rutting parameter values at 0.1 rad/s following asphaltenes modification. Additionally, the aging resistance of the modified binders improved, with the complex shear modulus aging index for short-term aging reduced by 20–23 % and for long-term aging by 44–48 % compared with neat binders. These improvements underscore the promising use of asphaltenes in sustainable asphalt binder modification.