DETERMINING PAVEMENT STRUCTURAL NUMBER FROM FWD TESTING

Abstract

A structural number is used as an indicator of pavement strength in a number of pavement design and deterioration models. In determining the structural number of an existing pavement structure, traditional methods of laboratory testing have become expensive and are not always appropriate. The parameter preferably is obtained from nondestructive deflection testing. Currently two techniques to determine structural numbers from surface deflections have been suggested and documented by AASHTO. A powerful alternative procedure for determining a pavement's structural number from falling-weight deflectometer surface deflections is presented. The approach has been verified and compared with other available techniques on 62 in-service pavement sections. The method is rapid, does not need mechanistic analysis tools, and is highly suitable for characterizing pavement strength in pavement management systems.