Viscoelastic continuum damage theory for fatigue analysis of 12 Brazilian asphalt binders and mixtures

Fatigue characterisation of asphalt mixtures is imperative for predicting pavement performance. Since cracking begins in asphalt binders, determining their fatigue properties helps establish cause-and-effect relationships with cracking in mixtures and pavements. This study analyses the fatigue of 12 Brazilian asphalt binders and mixtures using the linear amplitude sweep (LAS) test for binders and the direct tension cyclic fatigue test for mixtures. The results were interpreted with simplified viscoelastic continuous damage theory (S-VECD), and a pavement was simulated using FlexPAVE™ software. The findings indicate that the binder type alone does not predict the fatigue class through the fatigue factor of the binder (FFB), necessitating rheological damage analysis. Most mixtures showed good performance in pavement simulations, with the fatigue factor of mixtures (FFM) and fatigue classes not being sufficient for predicting fatigue performance. A linear correlation was found between FFB and FFM but not between FFB and simulated damage (N/Nf), though higher FFB typically result in lower N/Nf.