Evaluation of the Effect of Nano-Calcium Carbonate Mechanical Performance of Asphalt Binder and Mixture

The purpose of this research is to investigate and evaluate the effects of calcium nanocarbonate on the mechanical properties of bitumen and asphalt mixture. The laboratory program of this research includes the use of two percent calcium nanocarbonate additives (3%, 5% by weight of bitumen) to modify pure bitumen. Various tests including: penetration degree, softening point, stretchability, MSCR1, LAS2, indirect tensile strength, buckling modulus and dynamic fatigue and creep were performed. Fatigue test was performed based on four-point bending beam test with constant strain level in three levels of 600, 800 and 1000 microstrain with sinusoidal loading. The fatigue life of the samples was evaluated based on a fifty percent decrease in the initial hardness modulus. The results showed that the addition of calcium nanocarbonate increased the softening point and decreased the degree of penetration and stigmatization. Also, the bitumen rutting results showed that the addition of nano calcium carbonate increased the fatigue life of the samples. According to the results, the fatigue life of asphalt mixtures made with bitumen modified with calcium nanocarbonate is more than normal asphalt mixtures. Also, bentonite led to a relative increase in indirect tensile strength and hardness modulus of asphalt mixtures.