Finite element simulation of nondestructive testing for pavement structural evaluation

The factors affecting pavement condition deterioration and failure include load history, environmental condition, material degradation, and construction quality. Pavement structural evaluation is performed to select cost-effective maintenance alternatives. Many airport agencies are interested to assess the adequacy of their pavements for future operations of heavier aircraft. Deflection testing is conducted to evaluate the in situ pavement materials properties and structural-capacity. The standard backcalculation programs do not appropriately consider the effects of dynamic loading, pavement boundaries and cracking. This paper presents some results of three-dimensional finite-element computer simulations carried out to backcalculate pavement moduli from the measured surface deflection response of the pavement-subgrade models of asphalt and concrete pavements, subjected to a standard falling weight deflectometer (FND) load. A micromechanical approach is used to predict viscoelastic properties of asphaltic mixes. This paper demonstrates the effect of viscoelastic material properties on pavement responses dynamic FND loading.