Evaluation on the Effect of Zinc Oxide Addition to Aging Rate of Asphalt and Performance of Resilience Modulus in Asphalt Concrete–Wearing Course

Abstract

This study discussed the effect of the addition of the antioxidant Zinc Oxide (ZnO) on the aging rate of AC-WC coated asphalt and found out the effect of the addition of ZnO antioxidant on the stiffness of the asphalt layer. The aging of asphalt can be caused by two main factors, namely evaporation of light oil fractions contained in asphalt and oxidation. In this study, it showed that, compared to the addition of 5% and 15% ZnO to asphalt, the addition of 10% ZnO provided the most effective results on the asphalt base affecting the rheological properties of asphalt, namely reducing the penetration value by 1 dmm, increasing the softening point of asphalt by 0.5℃ but reducing the ductility by 10 cm. In the resilience modulus test which was carried out after aging at 135℃ for 0, 24, 48, 72, 96, and 120 hours, the modulus value containing ZnO was always smaller than that of asphalt without ZnO content. The addition of antioxidant Zinc Oxide (ZnO) antioxidant to asphalt had a positive effect on the aging rate of asphalt and the performance of the open-graded AC-WC resilience modulus of asphalt mixture was effective at an additional 10% level.