A Laboratory Study on the Effect of High RAP and High Asphalt Binder Content on the Stiffness, Fatigue Resistance and Rutting Resistance of Asphalt Concrete. Presented at 93rd Annual Meeting of the Transportation Research Board

This thesis investigates the effect of added asphalt binder content on the performance and volumetric properties of asphalt concrete mixes containing Reclaimed Asphalt Pavement (RAP). Mixes with three different percentages of RAP (0%, 20%, 40%) obtained from an asphalt producer and three different percentages of asphalt binder (design asphalt content, design +0.5%, and design +1.0%) were evaluated. Additionally, a laboratory produced mix containing 100% RAP with four asphalt binder contents (0.0%, 0.5%, 1.0 % and 1.5%) was also evaluated in order to determine the binder level that optimizes mix performance for the extreme case in RAP utilization. Performance of the mixtures was evaluated based on three criteria: stiffness (dynamic modulus), fatigue resistance (flexural beam), and rutting resistance (flow number). Results showed that a 0.5 % increase in binder content improved both the fatigue and rutting resistance of the 0 % and 20 % RAP mixes with only slight decreases in dynamic modulus. However, the addition of various amounts of binder to the 40 % RAP mix led to a significant decrease in rutting resistance with little or no improvement to fatigue resistance. Volumetric analysis was performed on all of the mixes to determine how the added binder content affecte