Integrated Finite Element Analysis Program to Evaluate Pavement Performance and Predict Non-Destructive Testing Response

The response of a pavement system under wheel loading has been a subject of research for many decades. Several models have been developed to predict pavement performance based on layer deformation and fatigue cracking. Among them stand out computer programs based on linear elasto-static layered systems and viscoelastic-plastic models; however, newer or more advanced constitutive models cannot be rigorously incorporated into them. In contrast, finite element techniques allow incorporation of nonlinear and viscoelastic-plastic behavior of the pavement materials but licensing of software and the need to train personnel greatly limits its use by highway agencies. A mechanistic-empirical (M-E) approach for the estimation of pavement performance is proposed and implemented into a software package called Integrated Pavement Damage Analyzer (IntPave). The program has the capacity of calculating pavement distresses, i.e. rutting and fatigue cracking, for flexible pavements under any type of traffic load using finite element analysis. On the other hand, damage equivalency has been defined by AASHTO based on an empirical approach, thus being necessary a more rational approach to estimate damage based on mechanistic-empirical models. Such methods are proposed for the determination of damage factors using IntPave to allow the comparison the level of distress caused by a heavy truck relative to a standard truck. Furthermore, a process based on the M-E models was developed to estimate permit fees based on the predicted pavement deterioration that a truck causes. Case studies are presented to evaluate damage caused by both legal and overweight trucks and by trucks with similar gross vehicle weights but different axle configurations, as well as determining the effect on the permit fee