Linking laboratory performance and mechanistic modelling to predict cracking resistance of asphalt overlays in cold climates

Cracking remains one of the main distresses affecting the durability of asphalt overlays in cold climates. This study presents an integrated evaluation of ten overlay mixtures from the MnROAD Reflective Cracking Challenge by combining laboratory performance testing, mechanistic modelling and early field observations. The mixtures included four control sections and six sections modified with additives such as rubber, plastic and fibres. Laboratory results showed that mixtures with softer low-temperature binders or modified with rubber and fiber additives generally outperformed the standard control mixture. Among the laboratory indicators, CPR, the Glover-Rowe mixture parameter, and FI showed the strongest alignment with early field performance. Among the mechanistic models evaluated, the IlliTC provided the closest overall alignment with the early field observations, particularly identifying the poorest-performing section and the sections with no measured reflective cracking. This stronger agreement is likely attributable to its incorporation of mixture-specific fracture and thermal properties. Overall, the findings highlight the value of advanced laboratory characterisation for improving the mechanistic evaluation of asphalt overlay cracking performance.