Valorization of recycled wastes in pavement preventive maintenance: A review on reclaimed asphalt pavement and recycled waste tire.

Pavement preventive maintenance (PPM) is critical to ensuring traffic efficiency, road user experience, and safety. However, it imposes significant costs in annual road infrastructure budgets because it requires high-quality and natural material resources. This study provides a systematic and comprehensive review on the use of recycled wastes as an alternative for the natural materials used in PPM mixes. Specifically, the use of recycled waste tires (RWT) and reclaimed asphalt pavement (RAP) in chip seals, microsurfacing, slurry seals, and thin asphalt overlays were discussed. The current state-of-practice in terms of material specification and mix design were comprehensively investigated for PPM mixes containing RAP (RAP-PPM) and PPM with RWT (RWT-PPM). Laboratory and field performances of waste-treated PPM mixes were elaborated and compared with conventional PPM treatments to determine the feasibility of the RAP-PPM and RWT-PPM technologies. Furthermore, current research gaps were identified, and prospects for future investigations were discussed. It is envisaged that this study can provide a sufficient theoretical basis for the widespread practical application and beneficial use of this valuable technology, towards promoting sustainability in pavement maintenance practice.