Impact of FWD Testing Variability on Pavement Evaluations

Airfield pavement evaluations commonly include nondestructive testing. These evaluations are used for projecting pavement performance and for designing pavement rehabilitation options. To apply reliability concepts to these prediction and design scenarios, it is necessary to learn more about the variabilities associated with nondestructive testing and pavement evaluation procedures. In this study, twelve sites around the southeastern United States were tested with both a falling weight deflectometer and a heavy-weight deflectometer. The data were evaluated using the military procedure. The test data and the pavement evaluation results were examined for spatial variability and for test device variability. Two primary conclusions resulted from this study. The first primary conclusion is that the current military evaluation procedure does not provide a consistent level of reliability for evaluation results. The second primary conclusion is that the magnitude of the load used for deflectometer testing affects the evaluation results.