Impact of Asphaltene Addition on Performance-Based Rheological and Failure Properties of Alberta Oil Sands-Derived Asphalt Binders

摘要

Seven Alberta oil sands-derived asphalt binders from Cold Lake, Athabasca, and Peace River origins were modified with varying amounts of asphaltenes and investigated for their hardening as well as Superpave™ performance characteristics based on standard rheological, relaxation, and strain tolerance properties. The Superpave performance grade is improved significantly through the addition of asphaltenes, yet it poorly reflects performance and fails to differentiate the quality of binders for fatigue and thermal cracking. In contrast, the temperature where the phase angle reaches 30° (T(δ=30°)) reflects cracking performance more accurately by revealing the change in performance of the binders with the addition of asphaltenes. Moreover, relaxation behaviour and strain tolerance values obtained from Dynamic Shear Rheometer (DSR) tests clearly indicate that addition of small quantities of asphaltenes to soft Peace River and Athabasca binders is beneficial as it improves the performance relative to binders from Cold Lake. The age hardening ratio determined from relaxation tests increases with increasing amounts of asphaltenes in all binders. The incorporation of small amounts of asphaltenes is deemed useful for softer binders, enabling user agencies to utilize Athabasca and Peace River materials in road construction without compromising performance and life cycle cost.