ABSTRACT
Permanent deformation in the form of rutting is one of the most common and critical modes of failures in flexible pavements in the wheel path under the repeated axle loads. Rutting occurs mostly in the asphalt layer and/or all other pavement layers. The Wheel Tracking Test (WTT) is a very common device for laboratory study and characterisation of rutting in Hot Mix Asphalt (HMA). However, the conventional setup of the device is fully confined and has drawback in the sense that it is unable to capture the shear deformation characteristics of the asphalt mixtures. This makes it difficult to analyse the permanent deformation resistance behaviour of HMA. Hence, a modified setup of the wheel tracker with controlled confining pressure was utilised in this study, which is standardised under ASTM D8292. In this study, three different confinement conditions: unconfined, partially confined with 1.35 kPa lateral pressure and fully confined were simulated. In addition, solid rubber wheel versus pneumatic rubber wheels were investigated. The plastic creep parameters derived from the uniaxial static creep test were used to develop a finite element model in Abaqus, and the validation of the experimental data was investigated. A good match was observed between the experimental and the predicted rut depths at different cycles. Strong correlations were observed between the experimental and the predicted rut depths at different cycles for individual wheel type and confinement.
