The properties of asphalt binder blended with variable quantities of recycled asphalt using short term and long term aging simulations

The objective of this paper is to characterize the rheological properties of asphalt binders blended with various amounts of asphalt extracted from a recycled asphalt pavement (RAP) mixture. Three asphalt binder aging states were simulated and evaluated: unaged, rolling thin film oven (RTFO) aged, and pressure aging vessel (PAV) aged. A Superpave PG 58-28 binder was applied as control binder and another four RAP binder percentages were studied in this research, 30%, 50%, 70% and 100%. Rotational viscosity testing was conducted with a Brookfield viscometer. Temperature and frequency sweep tests were conducted using a dynamic shear rheometer. Master curves were constructed based on the dynamic shear moduli (G∗). The results showed that there are significant differences in dynamic shear moduli (G∗) master curve performance for high percentage RAP binder blends versus virgin binders at the three aging states. Increasing RAP concentration and further aging conditions contribute to the increased stiffness and viscosity of RAP binder blends.