Date of Award


Document Type


First Advisor

Fini, Ellie


This thesis investigates the practical feasibility of using silica fume, an industrial waste material, to enhance the rheological properties of asphalt binder. It has been widely reported that asphalt binder oxidation reduces the service life of asphalt pavement by negatively impacting its rheological properties. When asphalt binder is oxidized, its viscoelastic properties are diminished; this can be evidenced by the reduction in asphalt phase angle as measured through dynamic shear and torsion tests. This can lead to a more brittle pavement, which is more prone to cracks due to thermal stress and traffic loading and leads to premature pavement failure. In this thesis, the effectiveness of the application of silica-fume-based additives to reduce asphalt oxidative aging is investigated. It is hypothesized that fine-graded silica fume with nano- to micro-level particle size can be used to reduce asphalt oxidation. To test this hypothesis, various percentages of silica fume were introduced to base binders; then a series of experiments in binder and mixture level was conducted to evaluate the effects of silica fume addition.