Rutting performance of asphalt mixture using simplified IDEAL-RT test method

Rutting resistance is one of the main performance characteristics against permanent deformation for hot mix asphalt (HMA). Different techniques have been developed for evaluating this property. Recently, a new technique called IDEAL Shear-Rutting Test (IDEAL-RT) has been developed for evaluating permanent deformation of HMA using a cylindrical sample (d = 150 mm × h = 62 mm) tested in three-point bending test technique. The main objective of this study is to assess the concept of IDEAL-RT on a Marshall specimen (d = 101.6 mm × h = 63.5 mm) due to the ease of fabrication and availability of suitable sample size. In this study, two types of mix (surface and binder course) from two sources of aggregates (Thumail and Nibaie) and 40/50 penetration grade bitumen from two sources (Erbil and Dorah) were used for fabricating the specimens for both sizes of HMA samples. A thorough comparison between laboratory samples and finite element (FE) analysis was conducted thoroughly. The results revealed an agreement in the IDEAL-RT performance for both sizes in terms of rank order. At the same time, the FE modelling results confirmed the compatibility in the outputs. Overall, this study confirms the viability of using the IDEAL-RT in evaluating rutting resistance using standard Marshall specimens.