Engineering and rheological properties of asphalt binders modified with microwave preprocessed GTR

Abstract

Many researches and field applications have proven that binders modified with ground tire rubber (GTR) can significantly improve rutting resistance potential and durability of asphalt pavement. However, GTR modified asphalt binder has higher viscosity and poorer hot storage stability than base one resulting in construction troubles, such as more energy consumption, extra stirring, reduction in asphalt mixtures performance and etc. The objective of this study was to investigate the engineering and rheological properties of binders prepared with microwave preprocessed GTR at high service temperature, medium temperature, and low temperature, respectively. The experiment included two particle sizes of GTR and five microwave preprocessing radiation intensities. The dynamic shear rheometer (DSR), force ductility test (FDT) and hot storage test were performed to evaluate the effect of radiation intensities and particle sizes of GTR on the engineering and rheological characteristics from low to high temperature. The test results show that microwave preprocessed GTR modified binders presented a reduction trend in composite viscosity, as well as rutting resistance potential after exposing to microwave radiation. In addition, fatigue and low temperature tension properties were jointly affected by microwave radiation intensities and GTR particle size. Otherwise, lower phase separation tendency compared with binder modified with GTR without microwave radiation was observed in this study. Thus, comprehensive consideration of radiation intensities and GTR particles sizes were recommended to apply in the field.