Lifetime Prediction Model for Pavement Repair

A software product is proposed to enhance lifetime prediction and design of structural pavements by including the effects of fatigue cracking. The fatigue lifetime prediction (FLIP) code will calculate incremental crack growth that occurs in pavements for cycles of stress below the yield stress. FLIP combines crack growth calculations with an extrapolation procedure to predict the growth of fatigue cracks over component lifetime and includes the redistribution of stresses and changes in compliance of pavement as fatigue cracks grow. Because FLIP explicitly includes the effects of cracking, it can be used to evaluate pavements that are already damaged. FLIP will be an integral component in the software suite for analysis of pavement response, damage, performance and vehicle dynamics being developed at FHWA as part of the Truck Pavement Interaction (TPI) research program. The Phase I objective is to demonstrate the feasibility of the model for predicting fatigue lifetime for damaged pavements. This will be accomplished in a three step program to: (1) implement the model into a Windows version of the code NIKE2D, (2) validate and improve the cracking model by comparing with response observed in selected tests and (3) implement the code into the FHWA pavement design suite.