Advancing asphalt mixture sustainability: A review of WMA-RAP integration

Abstract

The asphalt industry faces increasing pressure to reduce its environmental impact and improve economic efficiency. Warm mix asphalt (WMA) technologies have been developed as a promising solution to reduce the production temperatures of asphalt mixtures, thus improving energy efficiency and minimizing emissions. Besides, incorporating reclaimed asphalt pavement (RAP) material offers significant environmental and economic benefits by reducing the demand for virgin materials. However, high RAP contents present challenges such as binder hardening and poor adhesion among aggregates due to aging, limiting its application. This review delves into the interplay between WMA technologies and RAP, exploring their individual and combined effects on the environmental and mechanical performance of asphalt mixtures. By optimizing the selection and dosage of WMA additives, and balancing RAP content, it is possible to mitigate the challenges associated with high RAP content and achieve desired pavement performance. Future researches should focus on developing advanced WMA additives and techniques to further enhance the integration of high RAP content, ensuring both environmental sustainability and improved pavement performance.