The Effect of Styrene Butadiene Styrene (SBS) Morphology on Field Performance and Test Results: An Initial Study

Styrene butadiene styrene (SBS) is the most commonly used polymer modified binder (PMB) type. It provides substantial performance enhancement in seals and asphalts, compared to unmodified bitumen. However, there have been field failures, and difficulties with obtaining reproducible test results. The aims of the study were to clarify how the properties of SBS binders depend on morphology, and identify factors that control morphology, use this knowledge to determine the viscoelastic properties of SBS binders in different types of field surfacing and establish whether PMB specification test procedures need to be modified.