Investigation of rheological effects of waxes on different bitumen sources

Abstract

Wax in bitumen has been referred to as petroleum wax and is obtained from refining of paraffinic crude oils. The effects of wax on bitumen properties depend on the following factors: the source, chemical composition and rheology of the bitumen as well as the content, type, composition and crystallisation of the wax. There is a lack of literature reviews related to the effect of waxes on the rheology and properties of bitumen. The scope of this study is to evaluate the rheological properties of waxy bitumens obtained from different sources. Following the determination of wax contents by differential scanning calorimetry (DSC) and EN 12606-1, waxy bitumen properties were evaluated using conventional methods, rotational viscosity, dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The intermediate and high-temperature performances levels of bitumen were also determined according to the Superpave system by a DSR test performed on aged and unaged samples. Rutting performance of bitumens has been evaluated using zero shear viscosity (ZSV) and multiple stress creep recovery (MSCR) tests.