Refining laboratory procedure for artificial RAP: A comparative study

Laboratory aged, “Artificial RAP” is often used in controlled experiments in order to simulate the performance of paving mixtures containing RAP. Many different methods have been used to generate artificial RAP and they often modify the American Association of State Highway and Transportation Officials (AASHTO) R30 specification for oven aging gyratory compaction cylinders. Two modified AASHTO R30 methods were evaluated at 85 °C and 115 °C, as well as an artificial RAP created using PAV aged asphalt that had undergone one or two PAV cycles at 100 °C and short term aging. A staged extraction procedure using trichloroethylene solvent was used to evaluate a four layered binder system around the aggregate. Each layer was studied with Fourier Transform Infrared Spectroscopy (FTIR) and an aging index is computed for comparison.