Advanced fatigue and rutting characterisation of Polish asphalt mixtures based on the VECD model and viscoplastic shift model

Abstract

The advanced asphalt mixture performance-related specifications (AM-PRS) recently developed in USA can allow an optimisation of the design process of asphalt pavements thanks to the possibility to fully take into account the intrinsic material properties. In this study, four typical Polish mixtures, i.e. a Stone Mastic Asphalt (SMA) for wearing course, two mixtures for binder course with neat bitumen or Polymer modified Bitumen (PmB), and a mixture for asphalt base course with neat bitumen, were investigated by applying such advanced framework. The fatigue performance was studied through the simplified viscoelastic continuum damage (S-VECD) approach, whereas the rutting properties were assessed through the viscoplastic theory of the shift model. The findings were consistent with the composition of the studied mixtures, demonstrating the reliability and applicability of the AM-PRS even for typical Polish mixtures. Specifically, the high amount of soft PmB made the SMA mixture tough against fatigue cracking, but also more prone to rutting. The two binder mixtures exhibited good performance against both fatigue and rutting, and the polymer modification improved the toughness and increased the stiffness at high temperatures. The base mixture is expected to suffer fatigue cracking more than rutting, likely due to the low amount of bitumen and coarser aggregate gradation. These results can be used in the future for pavement performance predictions with FlexPAVETM software programme to ultimately optimise the design of Polish pavements.