ABSTRACT
In this study, a laboratory experimental program was conducted to investigate the fatigue behavior of four asphalt mixtures employing different VECD-based models and to highlight any differences in the evaluation of the mixtures’ cracking potential. Laboratory cyclic push-pull (tension-compression) tests were conducted on mixtures used at the field lanes tested at the Accelerated Loading Facility (ALF) of the Turner-Fairbank Highway Research Center. The experimental program included the evaluation of the dynamic modulus (E*) and the relaxation modulus (E(t)) master curves for the LVE characterization of the mixtures and the fatigue resistance assessment by means of push-pull tests. Fatigue tests were conducted in strain-control mode, one fixed frequency (10 Hz) and test temperature (19°C). The damage characteristic (C-S) curves were established for each mixture and predictive model and used for the estimation of the number of cycles to failure at specific simulated conditions. Results were also compared to the field performance. It has been found a sensibly different prediction of the fatigue life for all the HMA types and simulated conditions. The hierarchical trend between the materials is not constant and these differences may have significant implications in the pavement analysis and design.
