Rheological and chemical properties of field aged binders and their variation within the wearing course
Hilde Soenen, Xavier Carbonneau, Xiaohu Lu, C Robertus, Benoît Tapin
Abstract
Field ageing is investigated based on recovered binders. Fifteen sections were considered, consisting of unmodified and polymer-modified binders (PmB). Binders were recovered from the wearing course, after slicing the cores horizontally. To assess field and laboratory ageing tendencies, recovered binders were compared to a set of reference binders, tested before and after laboratory ageing. For three sites, the binders recovered from bottom slices were long-term aged and compared to the properties of top slices. Stiffness-based rheological parameters showed good relations to the carbonyl index. Field and laboratory ageing induced the same trends, but field ageing often turned out to be more severe. It was shown, for three sections, that a standard ageing test applied to the bottom slices is not enough to reach the ageing levels of the top slices. Finally, a relation between the vertical ageing profile and the void content of the corresponding asphalt mixtures was observed.