ABSTRACT
The AASHTOWare Pavement ME Design software represents a major development in pavement design and rehabilitation over previous empirical design procedures. This software requires comprehensive input data including traffic load distribution, bound and unbound pavement layer properties to do design analysis of pavements. This study focused on evaluating the effect of chemically-treated subgrade layers on flexible pavement performance as predicted by the AASHTOWare Pavement ME Design software. In this study, Lime-Treated Subgrade (LTSG) as well as mechanically-stabilized subgrade types was considered as subgrade soil treatment. Ten new flexible pavements with treated subgrade layer were analyzed to evaluate the effect of subgrade treatment. In addition, the effect of treated subgrade layer on new Jointed Plain Concrete Pavement (JPCP) design was also evaluated. The AASHTOWare software predicted higher design thickness for flexible pavements designed with mechanically-stabilized subgrade compared to the LTSG layer. Higher total permanent deformation was predicted for flexible pavements without stabilized subgrade layers. Pavements designed with mechanically-stabilized subgrade was predicted to have lower rut depth compared to those with LTSG. Top-down fatigue cracking was also found to be higher for the hot-mix asphalt pavements designed LTSG compared to the pavements designed with mechanically-stabilized subgrade. The rigid pavement thickness design was found to be insensitive to the subgrade soil treatment.
