Fatigue Performance Prediction of Asphalt Pavement Based on Semicircular Bending Test at Intermediate Temperature

The objective of this study is to correlate asphalt mixtures' crack resistance with their in situ cracking performance. Ten mixtures were obtained from a full-scale experiment at the Federal Highway Administration (FHWA) Accelerated Loading Facility (ALF), which were constructed with various contents of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS), two warm-mix technologies, and two asphalt binder grades. The mixtures' linear viscoelastic properties were assessed through dynamic modulus testing. Fracture resistance was characterized by the critical strain energy release rate (Jc), which was obtained from semicircular bending (SCB) tests at intermediate temperature. The increase in RAP/RAS content was found to enhance mixture's stiffness while reducing the mix crack resistance. No significant difference in terms of crack resistance was observed between the two used warm-mix technologies. The use of a soft binder was effective in improving the crack resistance of mixtures with a high RAP content. The generic fatigue model from the literature did not correlate well with the ALF test results; modification was achieved by introducing Jc as an indicator of crack resistance into the model form. The resulting Jc-based model exhibited an adequate correlation with field performance measured by the ALF test results.