@Article{, title={Evaluating The Effects of Micro and Nano Size of Silica Filler on Asphalt Cement Properties}, author={, Maan S. Hassanc and , Hasan H. Joni b and Hussein H. Zghair a*}, journal={Engineering and Technology Journal مجلة الهندسة والتكنولوجيا}, volume={38}, number={12part (A) Engineering}, pages={1632-1841}, year={2020}, abstract={This research study examines the practicability of using micro and nanosize silica to improve the asphalt characteristics. Asphalt cementpenetration grade of (60 /70) was prepared using (0%, 2%, 4% and 6%) ofsilica filler by weight of asphalt and investigated in terms of the softeningpoint, penetration, and penetration index, viscosity, and ductility values.To modify the asphalt binder, the silica powder was mixed by amechanical blender set at (2000) rpm at a mixing temperature of 140°C.However, the main challenge is an agglomeration of nano-silica powderwhich can reduce the ductility of nano silica modified binder. Therefore,this paper studies the efficiency of mixing period to obtain a homogeneouscomposite binder while alleviating the agglomeration issue. To do so, theeffect of periods of mixing ranged between (30 to 60) minutes wereexamined on characteristics of modified asphalt binders. Overall, theaddition of silica filler has an encouraging impact on the asphalt binderrheological properties. Also, the ductility value decreases with theaddition of nano-silica content, attributed to the huge surface area anddegree of agglomeration. Furthermore, results exhibited that 6% of microsilica powder and 4 % of nano silica powder were reasonable to developthe rheological properties

} }