Viability of using high reclaimed asphalt pavement (RAP) contents incorporating waste materials for eco-friendly paving applications: a systematic review.

The escalating costs of crude oil, the primary origin of binder, have remarkably surged in modern times, leading to an upswing in the overall expenses associated with bituminous blends. A viable solution to address this challenge entails the advancement of novel materials and technologies that incorporate environmentally friendly elements, waste products, and reused materials to produce asphalt mixes. This approach not only promotes the sustainability of the pavement industry but also contributes to cost-effectiveness. There is a growing trend towards integrating sustainable materials in road construction, reflecting an increased societal awareness of environmental consequences. However, ongoing efforts persist in the quest for optimal waste materials for the development of road pavements. The compatibility of RAP substances in the pavement is the primary challenge facing the incorporation of high RAP content. Hence, waste materials as additives may be incorporated to recover and/or improve the RAP binder and generate a binder identical to the original binder. This review elucidates the evolution of using high RAP contents, the obstacles encountered, and the economic and environmental advantages associated with the utilization of RAP, both with and without the integration of waste materials. Also, the study explores the effect of the RAP incorporating waste materials on performance behavior. In addition, this review provides a future direction for boosting the usability of RAP by incorporating waste materials in asphalt for sustainable road pavement.