Effects of utilization of rejuvenator in asphalt mixtures containing recycled asphalt pavement at high ratios

This study investigated the properties of asphalt mixtures, including recycled asphalt pavement, at high ratios. In addition, to improve the properties of asphalt mixtures containing recycled asphalt pavement, bitumen was modified with a rejuvenator at proportions of 2, 4, and 6% and used together with 35, 40, and 45% recycled asphalt pavement. Based on test results, the strength of asphalt mixtures increased as the ratio of recycled asphalt pavement added to asphalt mixtures increased. In addition, all combinations of recycled asphalt pavement and rejuvenator agent had higher indirect tensile strength values according to the reference mixture. The rutting resistance of asphalt mixtures increased as the ratio of recycled asphalt pavement added to the asphalt mixtures increased. Asphalt mixtures containing 45% recycled asphalt pavement and 2% rejuvenator-modified bitumen showed the best rutting resistance. The significance of the obtained results was determined with appropriate statistical analysis. So, it has been determined that the rejuvenator used in this study can effectively improve the properties of asphalt mixtures containing recycled asphalt pavement. Finally, the rejuvenator agent used in this study allowed the utilization of recycled asphalt at a higher ratio than the amount specified in the Highway Technical Specification.