An equivalence between methods of aging for determining the low-temperature performance of hot-mix asphalt concrete mixtures containing reclaimed asphalt pavement

Abstract

Asphalt pavements in cold regions are susceptible to thermal cracking. Current construction practice of adding reclaimed asphalt pavement to virgin materials further deteriorates the low-temperature performance of asphalt concrete. This study concentrates on finding equivalence between short-term aging of loose asphalt mixtures and long-term aging of compacted mixtures by following the AASHTO TP125-16. Asphalt mixtures made from two Superpave® mix designs, four different Reclaimed Asphalt Pavement (RAP) contents and six different aging periods at two different temperatures were analyzed in this study. RAP and Aging Indices were proposed to demonstrate the combined change in the performance of asphalt mixtures due to the addition of RAP and aging. It was found that four hours of additional loose-mixture-aging at 135 °C yields low-temperature performances similar to five days of compact-mixture-aging at 80 °C. Results found from this study contribute to the benefits of Bending Beam Rheometer as a potential quality control tool for low-temperature performance during construction.