Evaluation of the MEPDG Permanent Deformation Models in Louisiana Conditions

The newly developed Mechanistic-Empirical Pavement Design Guide (MEPDG) utilizes a suite of nationally-calibrated, empirical damage models for different trafficinduced distresses commonly found in flexible pavements. To facilitate the MEPDG implementation in Louisiana, this study was aimed to address the local validation and calibration of the MEPDG permanent deformation (rutting) damage models (i.e., the asphalt concrete (AC) rutting model and the subgrade rutting model) based on the local conditions in Louisiana. A total of 28 projects with two typical flexible pavement structures in Louisiana were selected in this study. The MEPDG input information was collected from a number of databases from Louisiana Department of Transportation and Development (LADOTD). The MEPDG predicted pavement rut depths were then compared to the measured rutting data retrieved from the Louisiana pavement management system (LA-PMS) database. The results generally indicated that the current MEPDG rutting models over-predict the total rutting for Louisiana flexible pavements, primarily because of the over-prediction of subgrade rutting. To perform a local calibration of the MEPDG rutting models, an optimization-based method was used. One advantage of the developed method is that it does not require measured permanent deformation data for individual sublayers.