Abstract
FWD testing and backcalculation have been conducted on pavement evaluation for many years. However, none of the existing backcalculation procedure is guaranteed to give reasonable moduli values for every deflection basin measured. To increase the precision of the backcalculation moduli, a new backcalculation procedure based on Extended Bayesian Method (EBM) was described in this paper. The advantage of EBM is to utilize prior information of pavement layers, as well as deflection for backcalculation of pavement. The practical backcalculation of FWD common test measurements indicates that the layer moduli of pavement can be estimated properly by this procedure, and the results are stable and reasonable. Finally, the influence of prior information on backcalculated results is also discussed.