A simulative approach to evaluate the feedback effect of water infiltration in pavements

Abstract

In low- to medium-volume traffic roads, a majority of flexible pavements consist of a relatively thin asphalt mix layer over a granular base. Water infiltration through cracks in the surface layer causes an increase in saturation and a consequent loss of stiffness in the base. This paper attempts to capture the feedback causal system that creates a vicious cycle of surface cracks to water infiltration to base deterioration and further surface layer cracking, specifically in wet climate/high-rainfall areas. A system dynamics model is presented that considers both traffic/fatigue-related logistic growth of surface damage and damage caused by a damaged base, which is also impacted by the total surface damage. The model demonstrates the latent feedback effect that leads to accelerated damage growth in the surface. Simulations show the significant effects of saturation and flooding. Finally, the impacts of using paving fabric and crack sealing at different levels are evaluated. Based on the conclusions, the recommendations are to either use properly asphalt-coated paving fabric or keep at least 90% of the cracks sealed, to avoid or reduce the potential of infiltrated-water-related damages in thin asphalt layer over granular base roads significantly.