Pavement material is characterized by number of failures modes at low and high temperature such as cracking, fatigue cracking, or permanent deformation which causes a reduction of quality and performance, Any improvement in service life of road pavements will be off course of a great economical advantage and any modifications of asphalt are attempts to extend the service life and improve the performance of asphalt pavements, In this study a forward investigation of Nano silica
Several physical properties of asphalt with and without Nano silica have been conducted which were penetration, softening, Ductility ; then studying its effect on the mechanical properties of Marshall Stability and Indirect tensile strength test ; by adding different contents of Nanosiica ,1 wt.%,2 wt.% and 4 wt.%. Results showed that the optimum Nanosilica is 2%. On the other hand, there is a significant increase in the mechanical properties and the durability of the modified mixtures i.e. with 2% Nano silica in comparison with the control mixtures.