Development of a Damage-based Phenomenological Fatigue Model for Asphalt Pavement

摘要

Bottom-up fatigue cracking is one of the major distresses for asphalt pavements.Accurate prediction of fatigue cracking for asphalt pavement is of paramount importancefor a cost-effective pavement design. The fatigue model in the mechanistic empiricalpavement design guide (MEPDG) is based on original Asphalt Institute model, with somemodifications. However, there are some controversies about the effectiveness of fatiguemodel in the MEPDG. The major concern exists on the use of dynamic modulus as keyparameter and there is no damage property of asphaltic mix to predict fatigue which isinduced by damage to the material. This study developed a damage-basedphenomenological fatigue model. The pavements at the Federal HighwayAdministration’s accelerated loading facility (ALF) were used to test the effectiveness ofexisting models, including the MEPDG fatigue model, and validity of the damage-basedfatigue model. The data used in this study included dynamic modulus and critical strainenergy density of HMA, and tensile strain at bottom of HMA layer and the fatigue life ofALF pavements. It was found that the damage-based model significantly improved theaccuracy of the prediction, when compared to the MEPDG fatigue model and otherconventional models.