Characterisation of rheological properties of sulfur-extended asphalt with/without crumb rubber

ABSTRACT

This study is to characterise rheological properties of sulfur-extended asphalts with/without crumb rubber at high, intermediate, and low temperatures using standard asphalt binder tests. Four dosages of sulfur (i.e. 0%, 15%, 30% and 45%) by weight of neat asphalt binder were used. The results indicated that a low level of sulfur addition, such as 15%, softened original asphalt binder. When the sulfur dosage was larger than 15%, the extra sulfur would act as fillers to stiffen asphalt binder. The addition of crumb rubber significantly increased high temperature performance grade. For sulfur-extended asphalts with/without crumb rubber, an increase in the sulfur dosage resulted in an increase of low temperature performance grade. Sulfur-extended asphalt with 15% sulfur exhibited the largest non-recovery creep compliance (Jnr) value, while the 30% and 45% exhibited the lowest values since more extra sulfur acts as fillers to stiffen asphalt binder. The addition of sulfur significantly decreased viscosity. The semi-circular bending fracture test results indicated that the mixture with the addition of 15% sulfur was softer and behaved in a more ductile manner than the others, which is consistent with the asphalt binder test results of high temperature performance grade and non-recovery creep compliance.

KEYWORDS:

• Rheological properties
• sulfur-extended asphalt
• crumb rubber
• multiple stress creep recovery
• semi-circular test

Acknowledgement

The authors acknowledge the financial support provided by the Saudi Aramco Chair on Asphalt Pavement at King Faisal University towards this work. The assistance from Dr. Amit Bhasin at the University of Texas at Austin is greatly appreciated.

Disclosure statement

No potential conflict of interest was reported by the author(s).