Rheological investigation of asphalt binder modified with nanosilica

The study investigates the use of nanosilica as a potential binder modifier. Nanosilica can be produced from rice husk and silica fumes and therefore is a cost-effective and environment-friendly modifier. Different percentages of nanosilica (0%, 0.5%, 1% and 3% by weight of asphalt binder) were added to VG-10 binder in a high-speed mixer. The influence of temperature, strain rate and frequency on viscosity was evaluated. Different rheological tests like time-temperature sweeps, Superpave rutting parameter (G*/sin & phi;), Multiple Stress Creep and Recovery (MSCR) Test, Creep tests, and Zero shear viscosity (ZSV) tests were performed on base asphalt binder and nanosilica modified asphalt binders. The addition of nanosilica enhanced the rutting potential of the asphalt binder. Fatigue evaluation using Linear Amplitude Sweep test showed that incorporation of nanosilica arrests the micro crack nucleation and therefore enhanced the fatigue performance of asphalt binder. Nanosilica particles act as a potential heating barrier and protect the host polymeric chains of the asphalt binder, thus improving its aging resistance. Nanosilica modified binders also showed an enhanced self-healing capability.