USE OF FALLING WEIGHT DEFLECTOMETER (FWD) MEASUREMENT DATA FOR PAVEMENT STRUCTURAL EVALUATION AND REPAIR DESIGN

Since 1996 the Falling Weight Deflectometer (FWD) is used to characterize the bearing capacity of pavement structures in Estonia. The deflection data of the load cell, mounted in the center of the loading plate of the FWD, is used for calculation of the pavement equivalent E-modulus. At the same time FWD has 6 additional load cells, which are mounted at different distances from the center of the loading plate and based on the FWD deflection measurement data we can create the deflection basin characterizing the pavement condition at the FWD test site. For further and more complete utilization of the FWD measurement data citerias for the different deflection basin parameters were determined. Based on those FWD measurement-based parameters - pavement equivalent E-modulus value and deflection basin parameters (surface curvature index - SCI, base damage index - BDI, base curvature index - BDI) - a system for pavement structural evaluation and repair design was developed.