2020 Volume 63 Issue 2 Pages 79-88
Recently, high-temperature and high-pressure water technology (“hydrothermal decomposition”) has been applied to various fields, suggesting the potential for recovery technology for aged bitumen. This study investigated the recovering effect of sub-critical water on aged bitumen based on evaluation of the physical properties, chemical properties, and dynamic rheology. Asphalt reacted for 15 min at 350 to 360 °C showed a significant recovering and modifying effects on physical properties such as penetration, softening point and ductility. Similar effects were found in bitumen with different composition. In addition, the chemical properties confirmed that bitumen recovered by the hydrothermal decomposition method has lower molecular weight and reduced oxidation. Bitumen after hydrothermal decomposition had improved fatigue crack resistance and flow resistance compared to virgin asphalt, indicating the potential of hydrothermal decomposition for recycling asphalt mixtures.
