Performance Evaluation of Stabilized Base Course using Asphalt Emulsion and Asphaltenes Derived from Alberta Oil Sands

Abstract

Stabilization of the pavement base course using asphalt emulsion is one of the strategies that improves the layer’s strength and, consequently, enhances the pavement performance. In this study, to improve the performance of the asphalt-emulsion-stabilized base course, asphaltenes derived from Alberta oil sands bitumen are added to the mix. Asphaltenes are a byproduct of the deasphalting process of oil sand bitumen and have no significant value in the asphalt industry. The modified mixes are prepared by adding different amounts of asphaltenes in powder form to the mix at ambient temperatures. Marshall stability and indirect tensile strength of the mixtures are evaluated using different contents of asphalt emulsion and asphaltenes. The low-temperature performance properties of the selected mixtures are investigated using an indirect tensile test and for the high-temperature properties a wheel-tracking test is conducted. The results of this study indicate that the addition of asphaltenes to the emulsion-stabilized mix significantly improves rutting resistance, with a slight increase in moisture sensitivity. However, the indirect tensile test results also reveal that modified mixes are slightly more prone to low-temperature cracking than are unmodified ones.