Property transitions of neat and styrene-butadiene-styrene (SBS)-modified asphalt binders from small, medium to large-amplitude oscillatory shears

Tests on asphalt binder are typically performed in its linear viscoelastic (LVE) range. In this research, the rheological properties of neat and styrene-butadiene-styrene (SBS)-modified asphalt binders were examined from 0.01% to 1000% at a high usage temperature, and focus was placed on their non-linear viscoelastic (NLVE) behaviours. Experimental variations and binder property changes in small, medium and large-amplitude oscillatory shears were revealed. Besides strain amplitude, the effects of polymer content, short-term aging and test frequency on NLVE behaviours were also analysed based on three quantitative methods. Additionally, polymers in asphalt binders were examined by using confocal fluorescence microscopy. The NLVE behaviours were found to be affected by shear strain amplitude, polymer content, shear frequency, and the interactions of such factors, but to a less extent by short-term aging. Besides polymer content, the size and morphology of polymer phase likely affect the property variations of modified asphalt binders. Large amplitude oscillatory shear (LAOS) test and morphology analysis help identify the threshold polymer content in producing high-quality polymer-modified asphalt binders.

Automated summary

This research examines the rheological properties of neat and SBS-modified asphalt binders in their non-linear viscoelastic range at a high temperature. The effects of strain amplitude, polymer content, shear frequency, and the interactions of these factors on the NLVE behaviors are analyzed. The study also explores the impact of short-term aging on the binders' properties and examines the size and morphology of polymer phases in the binders.