Evaluation of laboratory ageing procedures on cracking performance of asphalt mixtures

The objective of this study is to evaluate how the viscoelastic, fatigue, and fracture properties of asphalt binders and mixtures change as a function of ageing. Six plant-produced mixtures are evaluated in short term and three different long term ageing conditions (loose mixture conditioned 24 h @ 135°C, 5 days @ 95°C, and 12 days @ 95°C). Comparison between mixtures is conducted by constructing dynamic modulus master curves and evaluating various viscoelastic parameters. S-VECD fatigue and SCB fracture testing are used to evaluate fatigue and fracture behaviour. The binder characteristics are measured by conducting DSR testing on the binders extracted and recovered from the aged mixtures. The results show the 24 h @ 135°C and 12 days @ 95°C conditioning protocols induce statistically similar changes in linear viscoelastic properties but significantly different cracking performance indices. This indicates that various ageing protocols differentially impact the rheological, fatigue, and fracture propertie...