ABSTRACT
This paper presents the investigation of the deformation characteristics of two Open-Graded (OG) Unbound Granular Materials (UGMs) that are generally used in permeable pavement structures. Based on multistage Repeated-Load Triaxial (RLT) tests, the stiffness and resistance against Permanent Deformation (PD) of these materials were compared to their well graded (standard) counterparts. The OG UGMs showed similar stiffness characteristics as standard UGMs. On the other hand, the resistance against PD was slightly worse than the standard UGMs in a relatively dry state. However, the OG UGMs showed less sensitivity to moisture variation, yielding similar performance to that of standard materials at higher moisture content. The parameters of a stiffness model and a PD model were evaluated for these materials which may be used for prediction of rutting, estimating bearing capacity and for layer thickness design, using any suitable pavement design software.
