Laboratory evaluation of warm asphalt binder aging characteristics

As warm asphalt has been gaining increasing popularity in recent years, there are still several characteristics of warm asphalt, which are unknown. While several studies have been conducted to analyse the performance of warm asphalt mixtures, aging characteristics of warm-mix asphalt (WMA) binders are not known in great detail. This paper presents the results of a study to evaluate the aging characteristics of WMA binders artificially aged in the rolling thin film oven (RTFO) and the pressure aging vessel. RTFO aging was performed at 163 degrees C and a lower temperature to simulate warm asphalt aging. The results of this study indicated that reducing the aging temperature reduced the aging index and increased the m-values, but had no significant effects on G*/sin delta, G*sin delta and stiffness of the binders. Also, the addition of warm asphalt additives significantly increased the G*/sin delta values and lowered the m-values of the binders.