Evaluation of Fatigue Resistance of Modified Asphalt Mixtures by Nanosilica

The main objective of this research is to analyze the fatigue life and resistance against fatigue cracks of asphalt mixtures modified by nanosilica at intermediate temperatures. In this research،4 % and 6 % nanosilica (by weight of base binder) was added to binder. We made use of resilient modulus، indirect tensile strength and 4-point bending beam fatigue experiments to evaluate the modified asphalt mixture resistance and fatigue life. The results showed that the nanosilica modified asphalt binder significantly improved the fatigues life and the resistance of the asphalt mixture against fatigue cracks at intermediate temperatures. Adding nanosilica led to a significant increase in the indirect tensile strength and resilient modulus. The results of the 4-point bending beam fatigue test showed that the addition of nanosilica increased the fatigue life of the asphalt mixture. Therefore، it can be safely stated that adding nano-silica reduces fatigue cracks، and increases fatigue life and resistance of asphalt mixtures at intermediate temperatures.