DETERMINATION OF LAYER MODULI USING A FALLING WEIGHT DEFLECTOMETER

The increasing popularity of nondestructive pavement evaluation methods, based on interpretation of surface deflections, has prompted the development of several different types of nondestructive testing (NDT) devices. One such device is the falling weight deflectometer (FWD), which was used in the evaluation of layer moduli of three pavement sections. Several methods are currently available to interpret the FWD deflection data and backcalculate the layer moduli. Four methods selected for analysis of the deflection data included VESYS, ELMOD, OAF, AND MODCOMP2. A comparison of the material properties determined in the laboratory and the backcalculated values indicated that two of the four methods, namely, VESYS and ELMOD, had great potential for pavement evaluation.