Effect of moisture infiltration on flexible pavement performance using the AASHTOWare Pavement-ME

Abstract

Moisture in pavement subsurface layers has a major influence on pavement performance. In flexible pavements, variations in moisture content over time in the unbound base layer also depend on water infiltration through surface cracks in Hot-Mix Asphalt (HMA) layers. Higher moisture affects aggregate base layer resilient modulus, which leads to premature failure in pavements and reduced service life. This paper presents an approach for quantifying the effect of infiltration through surface cracks on flexible pavement performance. The models developed based on the Seasonal Monitoring Program (SMP) data show that increase in the amount of cracking will increase the base moisture content. As the moisture content in the base layer increases, its resilient modulus decreases. However, the decrease in base Resilient Modulus (MR) is about 3% and 33% for the pavement sections in Dry Freeze (DF)/Dry No-Freeze (DNF) and Wet Freeze (WF)/Wet No-Freeze (WNF) regions, respectively. The impact of MR reduction in the long-term predicted cracking show that with a 33% decrease in base MR, amount of surface cracking increased by about 30% while rutting will increase between 2% and 5% depending on HMA thickness.