Simultaneous evaluation of rutting-stripping performance and cracking resistance for asphalt mixtures

In this study, the influence of volumetric properties on viscoplastic (VP) deformation, stripping, and cracking performance of asphalt mixtures and the corresponding correlations between these three performance indices were comparatively investigated based on the Hamburg Wheel Tracking Test (HWTT) and Overlay Test (OT) results. A total of 20 different types of asphalt mixtures were comparatively evaluated and divided into two groups, namely: one group for the asphalt mixtures with stripping and another group for the asphalt mixtures without stripping. It was observed that the aggregate gradations of asphalt mixtures prone to stripping were mostly fine graded, and that, the effect of aggregate gradation was more pronounced than that of the asphalt binder content. Additionally, even though the average OT peak loads for all the asphalt mixtures were similar, the numbers of OT load cycles to failure for the fine-graded asphalt mixtures were over twice higher than those with coarse aggregate gradations. Also, whilst the VP deformation and cracking of the asphalt mixtures with stripping were positively correlated, the response-trends for the non-stripping asphalt mixtures were indeterminate. In general, the stripping characteristics were found to be related to the cracking resistance potential, further suggesting that the occurrence of stripping could be largely due to adhesive fracturing between the asphalt binder and the aggregates. Overall, the test results and study findings indicated a potential feasibility to predict and estimate the performance indices (i.e., deformation, rutting, stripping, cracking resistance, etc.) from amongst each other for the asphalt mixtures that are prone to stripping.