The effect of gamma-irradiated recycled polyolefins as asphalt binder modifier

Abstract

The current study evaluated the potential effects on the rheological properties of an asphalt binder modified with two recycled postconsumer polyolefins, polyethylene (PE) and polypropylene (PP), both with and without exposure to gamma-ray (γ-ray) irradiation, putting out a procedure that ensures benefits concerning the behavior and performance of asphalt pavements. The chosen analytical methods intend to investigate: the polyolefins’ chemical and physicochemical properties; the asphalt binders’ linear viscoelastic behaviour and damage characteristics; and the high-temperature storage stability. The results demonstrated: significant changes in the molecular structure of irradiated polyolefins, as well as the presence of contaminants in one of the recycled plastics; improvements in the rheological behaviour of the modified binders, showing better results performed after irradiated-polyolefins addition, with gains in rutting and fatigue cracking resistance; high separation tendency of polyolefins from asphalt binder matrix was observed, even for γ-ray exposure polymers.