Fatigue behaviour of plant produced asphalt mixtures through viscoelastic continuum damage model

Abstract

Fatigue cracking is one of the main failure modes in asphalt pavements, and is characterised by the accumulation of damage from traffic loading repetition. This research evaluated 24 asphalt mixtures effectively used in Brazilian highways. Hot and warm mixtures produced in plants were analysed, aiming to characterise and evaluate asphalt concretes with different aggregates, different types of binders and produced by different plants. Complex modulus and fatigue tests were performed. 2S2P1D rheological model (two springs, two parabolic elements and one dashpot) and the simplified viscoelastic continuum damage (S-VECD) model for fatigue were applied. The FlexPAVE™ software was used for analysis of pavement performance. The linear viscoleastic behaviour evaluation suggesting a higher stiffness of mixtures with conventional binder at low temperatures and high frequencies, and a greater stiffness of mixtures with polymer modified binder (PMB) for the domain of high temperatures and low frequencies. PMB and rubber asphalt mixtures generally have better fatigue performance than conventional binder mixtures. There are indications that more cubic and less lamellar aggregates provide better fatigue performance. As expected and reported in the literature, no correlations were found between viscoelastic linear behaviour and fatigue, except for a possible correlation with the phase angle master curve peak.