Framework for Rigorous Analysis of Moisture-Related Structural Damage in Flexible Pavements

The infiltration of water from precipitation through the hot mix asphalt layers in flexible pavements can lead to significant decrease in the moduli of the underlying layers, especially the base layer. As a result, the weakened pavement structure can suffer more damage and deteriorate faster compared with the same pavement under its normal condition. The objective of this study is to develop a framework that can lead to public-domain software that highway agencies can use on a regular basis to conduct a rigorous analysis of the moisture-related structural damage in flexible pavements. A framework of a numerical analysis that integrates the unsaturated hydraulic analysis with finite element structural performance has been developed using two open-source software packages. The framework has been applied to different pavement structures with different drainage systems. Analyses show a significantly longer period of time when the base layer experiences high degrees of saturation in a pavement with poor drainage compared with that for a pavement with proper drainage. Consequently, it is demonstrated that the pavements weakened because of moisture infiltration suffer a significantly higher amount of damage for a longer period of time under traffic, and thus experience shorter service lives. The proposed framework can be potentially used to evaluate and improve the resilience of pavement networks against extreme events that cause heavy precipitation, as well as to evaluate the impact of drainage structures and conditions on life during structural analysis and design of pavements.