The influence of long blending duration on physical and chemical properties of dual polymer modified asphalt binder with rejuvenator

With the current state of transportation infrastructure in the US, improvements need to be made to the construction materials to obtain a longer service life. Polymer modified asphalts are one solution for asphalt pavements to significantly improve the service life. If the polymers used for the modification of asphalt are derived from bio-renewable resources, they can have a vast contribution on increasing the sustainability of asphalt pavements. This research utilizes a master batching procedure in which a poly(styrene–butadiene–styrene) (SBS) polymer concentrate is formed before diluting and blending in a soybean derived polymer, sulfur, and functionalized soybean oil. The objective was to study the effects of blending duration on the rheological and chemical properties of the modified asphalt. Samples were taken periodically over 72 h to measure these properties. The results show that at short blending durations, the use of SBS and the bio-polymer causes aggregation of the polymers resulting in a heterogeneous morphology with reduced elastic performance. However, at longer blending durations the performance of the blends containing both polymers match or exceed the blends without the bio-polymer.