Estimation of Remaining Service Life of Flexible Pavements from Surface Deflections

Remaining service life (RSL) has been defined as the anticipated number of years that a pavement will be functionally and structurally acceptable with only routine maintenance. Usually RSL is computed from pavement condition survey results. This paper presents a methodology whether RSL was estimated from pavement surface deflections. Deflection data were collected with a Dynatest 8000 falling weight deflectometer (FWD) from 1998 to 2006. Nonlinear regression procedure in the Statistical Analysis Software and Solver in Microsoft Excel were used in model development. The results showed that a sigmoidal relationship exists between RSL and center (FWD first sensor) deflection. Sigmoidal RSL models have very good fits and can be used to predict RSL at the network level based on the center deflection from FWD.