Influence of RAP content on road performance of recycled asphalt mixture

Rutting test, semi-circular bending test, four-point bending fatigue test, freeze-thaw splitting test and hamburg wheel-tracking test were used to evaluate the pavement performance of recycled asphalt mixture with different RAP content. The results show that at a lower RAP content, the increase of RAP content makes the rutting resistance, fatigue resistance and water stability of recycled asphalt mixture improved significantly, and the crack resistance decreased significantly. The rutting resistance, fatigue resistance, water stability and crack resistance of recycled asphalt mixtures are significantly reduced at a higher RAP content (more than 30%). The crack resistance of asphalt mixture will be significantly reduced with the increase of RAP content. Warm mixing technology can promote the mixing between old and new asphalts, but it is not conducive to the water stability of recycled asphalt mixture. Moisture resistance of recycled asphalt mixture is sensitive to the change of RAP content. The different RAP content has a consistent effect on the road performance of recycled asphalt mixture, combined with the results of infrared spectrum analysis, and the recommended RAP content is 30%. © 2020, Jilin University Press. All right reserved.