High-RAP Mixtures with Rejuvenators and WMA Additives - Phase II

The use of reclaimed asphalt pavement (RAP) materials in producing asphalt mixtures offers great benefits by reducing costs for producers and highway agencies as well as reducing the environmental impact associated with the extraction, transportation, and processing of virgin materials. Currently, the state allows up to 40-50% of RAP for primary types of asphalt mixtures. Maximum use of RAP materials into asphalt mixtures has been desired; however, it is not a simple task because of undesired inherent characteristics of RAP such as aged (stiff) asphalt binder and inconsistent aggregate properties. To overcome the inherent concerns of RAP materials, many researchers have made significant efforts in various ways. Research outcomes and findings from the previous effort resulted in consequential research needs for more specific investigation of high-RAP mixtures with rejuvenators in order to achieve realistic implementation into future high-RAP paving projects. In the previous research, the dosage of rejuvenators and their blending procedures were followed based on producers’ recommendation. Although the recommended practices satisfied research goals set for the previous study, it is necessary to further investigate how mixtures/materials perform due to different treatments of rejuvenators so that an optimum rejuvenating practice for the state can be achieved.