Investigation of aging effect on asphalt binders using thin film and rolling thin film oven test

Abstract

The effect of short-term aging temperature according to Superpave protocol on rheological properties of asphalt binder using thin film oven (TFO) and rolling thin film oven (RTFO) test was investigated. To evaluate these different aging conditions, two types of unmodified binders and a crumb rubber modified binder (CRMB) was used at three different aging temperatures 163°C, 177°C, and 195°C. To simulate the effect of temperature used during the preparation of CRMB in laboratory and ideal mixing temperature corresponding to 170 ± 20 cP, 177°C and 195°C has been incorporated, respectively. The rheological characterizations of these binders were obtained using dynamic shear rheometer for before and after short-term aging. On the basis of rutting parameter, nonrecoverable creep compliances (J<inf>nr</inf>) and percent recovery (%R), as well as the RTFO aging process were found to be more effective than the TFO test for all the selected oven temperatures. However, the complex shear modulus |G*| of the base binders were equivalent to modified binders at 195°C. Additionally, on the basis of frequency sweep test and viscosity curve, the effect of short-term aging in a sample was investigated. However, at 195°C, the flow properties were significantly different for unmodified base binder, except for rubberized binders. From this study, based on its characterization, it is possible to use TFO or RTFO tests at a higher temperature to simulate the aging process for rubber modified binder to the actual hot-mix asphalt process. © © 2019 by ASTM International.