Morphological evaluation and quantitative effect of sulphuric extension on B160/220 rheological behaviour at high temperatures

A partial substitution of bitumen binder with sulphur in asphaltic concrete mixtures has been said to result in the better performance of the mixture. To further test this supposition, penetration grade soft bitumen (B160/220) extended with granular sulphur up to 50% by weight was investigated to observe the high temperature effects of the extension. To this end, this study has utilized various viscosity tests, as well as Dynamic Shear Rheometer (DSR). The samples were also subjected to short and long term ageing and further investigated by DSR. Lastly, Scanning Electron Microscopy (SEM) was used to study the morphology of the material in order to characterize the nature of the continuous phase and the fineness of the dispersion of the discontinuous phase. The results of these tests and analyzes found that sulphur extension, particularly at higher contents, increases permanent deformation (rutting) performance and reduces optimum mixing and compaction temperature, thus resulting in both lower costs and better performance.