Utilization of sulfur and crumb rubber in asphalt modification

In this study, waste crumb rubber and sulfur were utilized to enhance the performance of asphalt binder for pavement applications. About 20-50% of sulfur and 1-6% crumb rubber were used. Melt properties were investigated using thermal analysis, dynamic and steady shear rheology, and artificial aging. Rheological tests were carried out in ARES rheometer. Both steady and dynamic shear rheology showed that crumb rubber improved the viscoelastic properties of the sulfur-extended asphalt binder. Crumb rubber modification reduced temperature susceptibility of sulfur/asphalt, and increased the upper grading (performance) temperature of sulfur asphalt. The combined effect of sulfur and crumb rubber reduced the activation energy compared with that of pure asphalt. Zero-shear viscosity and strategic highway research program rutting parameter (G*/sinδ) improved by crumb rubber incorporation into the sulfur asphalt binder. Short-term aging improved G*/sinδ with slight increase in activation energy. The addition of sulfur to asphalt matrix increased the viscoelastic properties (G′ and G″) of sulfur asphalt. The addition of crumb rubber to sulfur asphalt enhanced the temperature resistance of the binder. Utilization of waste crumb rubber and sulfur in asphalt modification proved to enhance asphalt pavement life. In addition, utilization of such wastes can help in meeting the extra demand for asphalt, reduce the pavement cost, and help in solving a waste disposal problem.