Influences of aging conditions on the rheological properties of asphalt binders

Reliable assessment of asphalt binder aging is important for material selection and the prediction of asphalt property changes in field pavements. The apparent property changes of asphalt binder with aging, however, are affected by aging conditions. In this study, three aging treatment methods were applied to five types of asphalt binders, and the longest aging treatment period lasted for 1.5 years. Asphalt binder samples obtained during the aging treatment processes were systematically tested for dynamic rheological properties. The apparent aging susceptibility of asphalt binders was found to be affected by aging conditions. Thin-film aging under a more 'natural' condition appears to be quite effective in accelerating the aging process. The changes of the coefficients in the Christensen-Anderson model and the Williams-Landel-Ferry equation in the tests suggest that binders' dynamic rheological properties during the long-term aging process may be reliably predicted through laboratory tests. This is conditioned on the binders having been artificially aged to pass the 'spurt' reaction stage and data points being collected from the 'steady' reaction stage under more 'natural' aging conditions. To predict asphalt binder aging in field pavements, additional research is needed to consider the influences of asphalt mixtures.