Life cycle assessment and multi-index performance evaluation of semi-flexible pavement after composite modification by using fly ash, rubber particles, warm mixing asphalt and recycled asphalt pavement

Semi-flexible pavement (SFP) has excellent potential to improve pavement performance and durability. This study aims to reduce energy consumption and emissions in the whole life cycle of SFP based on ensuring its good pavement performance through applying fly ash, rubber particles, warm mixing technology, and recycled asphalt pavement (RAP) in SFP. It is observed that after the cement in the cement-based grouting material is replaced and modified with fly ash and rubber particles, the energy consumption and emission of SFP in the whole life cycle are significantly reduced. Compared with the gain effect of energy saving and emission reduction brought by cement replacement, the gain effect of environment-friendly modification of asphalt concrete matrix skeleton is in general. In particular, the application of RAP with high content will instead increase the energy consumption and emissions of SFP in the whole life cycle. At the same time, it is also found that the fatigue resistance of SFP has a significant impact on its energy consumption and emissions. It is a crucial method to reduce the energy consumption and emission of SFP in the whole life cycle to replace and modify the cement in the cement-based grouting materials by using environmentally friendly materials or technologies such as fly ash and rubber particles, and to guarantee or improve the performance of SFP.