Review on the Use of Instrumented Pavement Test Data in Validating Flexible Pavement Mechanistic Load Response Models

For designing pavement structures effectively and efficiently designers are moving from the old empirical design approach to the new Mechanistic Empirical (M-E) pavement design procedure. In M-E design, the pavement responses in terms of stresses and strains have greater influence on the performance prediction. Many theoretical equations were developed by researchers in the past fifty years to predict pavement responses under different loading conditions. The overall accuracy of the models are in question while considering unbound base materials, behaviour of hot-mix asphalt and dynamic moving loads applied by traffic. Despite this, layered elastic model continue to be the state-of-the practice for most pavement design and analysis applications. To make sure that the accurate pavement response model is being used in the M-E design, this mechanistic load response model has to be validated with measured pavement responses under traffic or applied loads. In this regard, instrumented pavement testing facilities play an important role in validating the mechanistic load response models by measuring the pavement responses from the field through proper instrumentation and comparing them with theoretical responses. In this paper, a detailed review and analysis on the major research works conducted in Europe and United States over the past fifty years on flexible pavements starting from the TRRL study in 1962 to the recent research at the NCAT Test Track to use the instrumented pavement test data to validate the load response model and their outcome is presented along with the efforts needed to increase the model accuracy.