A combined serviceability and distress pavement performance model for estimating remaining service life of flexible pavements

Abstract

A procedure is developed to estimate the remaining service life of flexible pavements based upon predicted ride and distress conditions. These conditions are forecast using equations that involve measurable values of material properties, climatic conditions, and design factors. In particular, life predictive models are developed for the Texas flexible pavement network. Predicted pavement lives are correlated with actual Texas data and acceptable results are obtained. The most significant distress types affecting pavement service life were identified using a discriminant analysis approach. For each of the prevalent Texas flexible pavements the probability of needing rehabilitation is assessed for different levels of ride and distress, using discriminant functions. A second method for estimating the remaining service life in terms of maximum likelihood estimators is also developed. Curves for estimating service life are constructed for different categories within each of the following three prevalent flexible pavement types: asphalt concrete, overlaid and surface treated. Present worth and savings/cost analyses are provided to assess the economic impact of delaying rehabilitation decisions once the predicted life is reached. This analysis considers maintenance, user and rehabilitation costs.