ABSTRACT
Nondestructive tests used in pavement engineering can be broadly divided into several categories: nuclear equipment, deflection based, electromagnetic, and seismic equipment. A falling weight deflectometer (FWD) is extensively used for estimation of pavement layer moduli and for determination of structural condition of pavements. The information obtained from FWD testing can be used in structural analysis to determine capacity, estimate expected performance life, and design a rehabilitation plan for pavements. Deflections prior to and after pavement rehabilitations are done to evaluate the effectiveness of specific rehabilitation methods. An FWD can also be used to test load transfer efficiency (LTE) of joints within concrete pavements. American Society for Testing and Materials standards are available for use of an FWD for pavement deflection-based testing. As a result, the FWD has become the principal nondestructive testing tool for pavement engineers. Nondestructive instruments such as ground-penetrating radar (GPR) have now become valuable tools for pavement engineers for providing the data necessary for using an FWD.
