EVALUATION OF PAVEMENT IN FLORIDA BY USING THE FALLING- WEIGHT DEFLECTOMETER

A method is presented by which mechanical properties of a pavement system can be determined by using nondestructive test methods that are now available. The ultimate goal is the establishment of rehabilitation criteria for existing flexible pavements that use purely analytical (as opposed to empirical) relationships. More specifically, the use of the falling-weight deflectometer (FWD) is discussed. Several sections of Interstate 75 in Florida were chosen in order to determine material characteristics of the pavement layers. These sections were also tested with the Dynaflect apparatus. Data developed from the FWD and Dynaflect deflections were accumulated and elastic moduli for the typical section were determined by using a computer program developed at the Florida Department of Transportation: in situ stress-dependent elastic moduli, four layers (ISSEM4). The elastic moduli were then compared with other test results, and a good correlation was indicated. How such mechanical properties may be used in an appropriate structural analysis to better locate and control distress parameters in the pavement system is outlined. Such analysis is possible from the knowledge obtained in situ of the various structural layers involved. (Author)