Plastic Deformation of Recycled Base Materials

Abstract

Large-scale model experiments (LSME) simulating field conditions were conducted on prototype pavement structures to characterize the elastic and plastic deformation of three base course materials: recycled pavement material (RPM), road surface gravel (RSG), and Class 5 granular base. The RPM and RSG were evaluated with and without stabilization using cementitious fly ash. RPM and RSG accumulate permanent deformation more readily than conventional base course, and therefore flexible pavements constructed with RPM and RSG can be expected to experience greater rutting. In contrast, stabilization of RPM and RSG with cementitious fly ash reduces permanent deformations to very small amounts. Thus, flexible pavements constructed with stabilized RPM and RSG should not rut more than flexible pavements constructed with conventional base course. Relationships between plastic strain at 10,000 cycles and summary resilient modulus are presented for unstabilized and stabilized RPM and RSG.