Development of a Soybean-Based Rejuvenator for Asphalt Mixtures Containing High Reclaimed Asphalt Pavement Content

In spite of its economic and environmental benefits, the use of reclaimed asphalt pavement (RAP) is limited due to the impact of aged binder on the performance of asphalt pavements. Currently, one of the most popular methods to mitigate the aged RAP binder is the addition of a rejuvenating agent. Such an agent acts to restore life to the aged binder thus making it less brittle. The main objective of this study is to evaluate a soybean-based byproduct as a RAP bio-rejuvenating agent. To achieve this objective, asphalt mixtures were designed containing various RAP types and content, and three different percentages of bio-rejuvenator. Test specimens of the various mixtures were produced and tested to determine complex modulus, flow number, and fatigue cracking characteristics. The results indicate that increasing the percentage of bio-rejuvenator improves the viscoelastic parameters and results in a significant improvement in fatigue cracking properties of asphalt mixtures containing RAP, but also slightly decreases rutting performance.