application of falling weight deflectometer (fwd) data and energy ratio (er) approach for cracking performance evaluation of asphalt pavements

This study primarily focuses on evaluating the falling weight deflectometer (fwd) time history data for use in relative cracking assessment of asphalt pavements. eight field project sections with a similar pavement structure were selected for evaluation; they include sections with and without the evidence of cracks. fwd tests were conducted for all selected field sections at a similar temperature to obtain load–deflection time history data. the results of the fwd-dissipated energy were further compared with the results of the energy ratio (er), which is a well-known performance-based fracture property previously introduced for the cracking performance evaluation of asphalt mixtures. pavement structures with the existence of cracks showed significantly greater fwd-dissipated energy and maximum deflection indicating a relatively higher rate of deterioration and/or damage for the pavement systems. additionally, a proportional relationship identified between rate of change in normalized er and fwd-dissipated energy confirmed that the fwd time history data was able to effectively differentiate pavement structures with and without the existence of cracks. comparative results between the fwd-dissipated energy and the er further support the validity of application of fwd-dissipated energy and the maximum deflection as a reliable material and/or pavement structural response indicator that can be used for cracking performance evaluation of asphalt pavements.