Insights into Polymerization-induced Phase Separation of Epoxy-Bitumen Systems and Strategies to Tailor High-Performance Bituminous Materials

The utilization of epoxy-based polymers as bituminous modifiers in developing durable and long-lasting pavement structures have gained increasing interest over the last years showing evidence of high performing materials (1-8). It has been noticed that the addition of epoxy-based modifier into bitumen lead to materials with superior characteristics against oxidative aging (1, 3, 8). Next to aging resistance, the incorporation of epoxy modifiers in bituminous materials has added functional benefits, such as improved resistance to moisture damage and fatigue cracking (5, 6). Despite the evidence of aging resistance in epoxy-asphalt concrete mixes, the influence of the epoxy-based polymers on the bitumen aging and the microstructure morphology of newly formed systems have not been fundamentally evaluated yet. Within the scope of this research, the aging susceptibility of epoxy modified bitumen has been investigated. The extent of aging has been probed by using a Fourier Transform Infrared spectrometer and also rheologically evaluated using a dynamic shear rheometer. Furthermore, an improved compatibility between epoxy and bitumen at the microstructural level defines the long-term chemo-mechanical performance of EB systems in a controlled manner. Thus, another aspect of this study was to investigate the morphological and interfacial characteristics of EB microstructure.