Loading Mode Effects on Pavement Deflections

Pavement deflection data collected using static (the Benkelman Beam), vibratory (the Road Rater), impulse (the Falling Weight Deflectometer), and vehicular loading have been used to identify and explain the factors affecting pavement response to different loading modes relevant to structural pavement evaluation. Pavement parameters derived using the different loading mode devices are shown to be loading mode and device dependent. Comparisons among different testing devices and methods indicate that the Falling Weight Deflectometer best simulates the pavement response under moving trucks. The Road Rater induces a stiffened response of the pavement-subgrade system due to the steady-state harmonic loading and static preload, and the quasi-static loading with the Benkelman Beam induces the highest deflections in most pavements.