Evaluating mechanical properties of stone mastic asphalt modified with Nano Fe2O3

- The increased amount of fatigue life of samples modified with optimum percentage (0.9% nano) compared to the control samples is between 15 and 35%.
- Using the bitumen modified with 0.9% Nano Fe2O3 in producing stone mastic asphalt mixtures can decrease the hot mix asphalt thickness.
- Results show that the increased rutting depth in all the modes is increasing with the usual rate.
- The amount of rut depth of asphalt samples containing 0.9% Nano Fe2O3 is about 25-40% lower than control samples.

The pavement of roads during their lifetime suffered from different damages such as cracks and rutting. Due to the growing trend of amount of traffic loads, the engineers attempt to improve the functional characteristics and properties of hot mix asphalt using the additives. These modifiers are used because the bitumen cannot have proper performance in all the environmental and loading conditions. Nano-materials are one of the newest technologies quickly developing in various sciences. Numerous benefits of the technology make the pavement researchers use it to improve the hot mix asphalt. This research aimed to evaluate the effect of adding different percentages of Nano Fe2O3 on the mechanical properties of stone mastic asphalt. The results show that Nano Fe2O3 can improve the mechanical properties of stone mastic asphalt to an acceptable level so that the stiffness modulus of the mixtures have improved due to using nano-material and the mixtures strength is also enhanced against the fatigue. Additionally, with addition of Nano Fe2O3, the strength of hot mix asphalt against rutting is also improved to an acceptable level.