Rutting Susceptibility of Asphalt Mixes with High RAP Content Using Rheological and Performance-Based Test Methods

摘要

The rutting susceptibility of asphalt mixes containing high amounts of Reclaimed Asphalt Pavement (RAP) was evaluated through a laboratory testing program. A commonly used PG 64-22 asphalt binder, RAP, aggregates and mix design sheets required for the production of an asphalt mix with a nominal maximum aggregate size of 19 mm containing 35% RAP were collected from a local asphalt plant in Oklahoma. The rutting susceptibility of the laboratory-produced asphalt mix was determined using the Hamburg Wheel Tracking test. The asphalt mix with 35% RAP content was found to exhibit satisfactory rutting resistance. Also, asphalt binder was extracted from the collected RAP and blended with the PG 64-22 binder at a rate of 40% by the weight of binder. The rheological characterization of the asphalt binders was conducted using Multiple Stress Creep and Recovery (MSCR) and Superpave® methods. The continuous high temperature PG grade of asphalt binder was found to increase and the non-recoverable creep compliance (J_(nr)) value was found to decrease with the addition of RAP binder to the neat binder. The findings of this study are expected to help pavement engineers in Oklahoma to understand the performance properties of asphalt mix with high RAP content.