Prediction of moisture migration in flexible pavement systems: An evaluation of the enhanced integrated climatic model

Superpave was introduced by the Strategic Highway Research Program (SHRP) in 1992 and was adopted by the Arkansas Highway and Transportation Department (AHTD) in 1995. Superpave designs typically use more coarse-graded aggregate blends than the conventional Marshall asphalt mix design. Because of this, Superpave allows more water to migrate into pavement systems, which can result in a variety of water-related problems. These water-related problems can not be well understood until we have a mature understanding of the exact nature of moisture migration in pavement systems.;To get an understanding of the moisture migration pattern in pavement systems, two test pads were constructed at the University of Arkansas and one field test site on Highway 253 in Ft. Smith was developed. Extensive laboratory testing of pavement materials was performed to obtain engineering properties of these materials. Environmental factors including air temperatures, precipitation and groundwater levels, along with pavement responses to environmental factors including surface and subsurface runoff, moisture content, and soil temperatures (only in the field test site) in the pavements were also measured at both sites for relatively long periods.;Based on statistical analyses of the laboratory and field test results, predictive models were developed to predict moisture contents at various levels in the pavement. Additionally, a water migration pattern through the pavements was obtained. A water balance analysis was also performed on one of test pads and a water balance was generally achieved using the proposed pavement storage model and measured surface runoff. The Enhanced Integrated Climate Model (EICM) was also evaluated in Arkansas by comparing predicted with measured data at both sites. Finally, a Finite Element Model (FEM) was created and calibrated based on measured data.