Engineering Characterization of Sulphur Modified Bituminous Binders

The increased demand on bituminous flexible pavements, due to heavy traffic loads, tire pressures, and extreme climatic conditions, has intensified efforts to enhance fatigue and rutting resistance using modified bituminous binders. Modifiers globally are improving the rheological and morphological properties of bitumen, with rheological testing providing critical insights beyond conventional methods.This study explores modifying viscosity grade (VG 30) bitumen with commercial sulfur sourced locally, focusing on both unaged and aged samples analyzed through a Dynamic Shear Rheometer (DSR). The objective is to establish optimal binder conditions by assessing parameters such as phase angle and complex shear modulus, which influence fatigue and rutting resistance.Sulfur was added to bitumen at six temperatures—100°C to 150°C—and mixed at five intervals (5 to 30 minutes), with concentrations of 1% to 5% by weight. Results indicated that the optimal modification was achieved with 2% sulfur at 140°C for 30 minutes, yielding enhanced rheological properties and meeting standard requirements.