STRUCTURAL BEHAVIOR OF PAVEMENTS USING NDT METHODS ---PROCEEDINGS OF THE THIRTY-SECOND ANNUAL CONFERENCE OF THE CANADIAN TECHNICAL ASPHALT ASSOCIATION

Non destructive testing of pavements has evolved from the Benkelman beam to the more advanced load-deflection equipment, such as dynaflect and falling weight deflectometer. This project was initiated to develop a method to predict the resilient moduli in a four-layer pavement system using ndt deflection measurements obtained from dynaflect and fwd. Employing an elastic multi-layer computer program, a series of complex prediction equations were developed for the dynaflect using a modified sensor configuration. The results indicate that the deflection response contribution for the subgrade, subbase, and combined surface and base courses could be separated using specific sensors within the array used in the simulation analyses. The simplicity of the dynaflect analysis could not be duplicated by the fwd because of design features which did not allow discrimination between the influence of different pavement layers.