Development and validation of an accurate, precise and safe method for the acceptance testing of recovered asphalt binder

Abstract

With the ever-increasing use of recycled asphalt pavement (RAP) in road construction, extraction and recovery of binders from mixtures as placed becomes a critical aspect of quality assurance testing. However, current extraction and recovery methods are associated with shortcomings, as they are often time consuming, costly, inaccurate and involve toxic solvents. The objective of this study was to develop a practical and more environmentally friendly protocol for the accurate and precise acceptance testing of recovered binder. The process uses a low toxicity solvent for extraction, followed by simple filtration, evaporation and thin film oven aging. Residual solvent is removed from the binder during initial thin film oven aging and fines are found to have an insignificant effect on the rheological properties of importance. Results of this study provide guidance for further optimization of a simplified extraction, recovery, and aging protocol for the acceptance testing of asphalt binder and mixture.