Performance Evaluation of WMA Made with Reclaimed Asphalt Pavement and Para-Fiber

Asphalt recycling not only is one of the effective approaches to increase the efficiency of the existing budget and capital which is used to protect and improve the road network but also leads to conserve natural resources and save expenses. However, the process of producing Hot Mix Asphalt (HMA) using Reclaimed Asphalt Pavement (RAP) leads to hardening of bitumen and quite a bit of environmental pollution which is derived by emission of toxic gases. Besides, reducing environmental pollution as well as saving energy, reducing the temperature in Warm Mix Asphalt (WMA) technology decreases aging and stiffness of bitumen caused by oxidation. Furthermore, by utilizing WMA technology, better working conditions regarding lower heat rate and emission of poisonous materials are provided.  To reduce the costs and the environmental pollution caused by asphalt production as well as improve the performance of asphalt, this research evaluated two approaches, including WMA with Kaowax additive and RAP techniques. The additive of Para-fiber with different values was also used to improve the functional properties of the asphalt. Resilient modulus, dynamic creep, and fatigue tests were performed to compare and evaluate the performance of asphalt mixtures. Given the results, in addition to improvement of the resistance against permanent deformation, utilizing RAP causes an increase in resilient modulus of the mixture, the reason lies in increasing the stiffness of asphalt mixture because of adding RAP. According to the results of fatigue tests, by adding RAP, the fatigue life of the mixture is significantly decreased. On the contrary, by adding Para-fiber, the fatigue life is considerably improved. It seems that tensile resistance and high flexibility of Para-fiber can be considered as the reason for improving the fatigue function of asphalt mixture. Thus, the costs and environmental pollutions can be reduced; meanwhile, an asphalt with good function can be produced.