The role of bio-based additives in achieving sustainability in asphalt pavements

Abstract

Increased service demands from asphalt pavements due to ever-increasing volumes, coupled with the aging of highway networks, and calls for improved sustainability across the industry, have rendered the need for smart and sustainable pavement material and design more important than ever. While chemical warm mix additives and rejuvenating technologies have been utilized in pavement materials at various scales of research and practice in the past, in recent years bio-based additives have emerged as increasingly practical solutions for potentially achieving more sustainable pavements, offering the prospect for high performance combined with environmental and economic sustainability. Adaptation of chemical warm mix additives and rejuvenators in practice requires a working knowledge on the definitions, relevant evaluation criteria available to the practitioner, and, perhaps most importantly, demonstrated experience of successful application in practice. The present study will review current efforts underway in the industry to incorporate bio-based chemical warm mix additives and rejuvenators in performance-based design methods for HMA and WMA, using real world Balanced Mix design (BMD). Examples including comprehensive research being carried out in conjunction with NCAT and MnROAD research and test facilities will be reviewed to illustrate the utilization of such concepts in practice today.