Mechanical characterization of warm mix asphalt mixtures made with RAP and Para-fiber additive

Abstract Asphalt recycling can help reserve natural resources and save money. However, in producing hot mix asphalt (HMA), utilizing reclaimed asphalt pavement (RAP) high heat rate is produced which leads to the stiffening of asphalt binder and producing toxic gases. This in turn will cause massive environmental pollution. As a money-saving technology, Warm Mix Asphalt (WMA) produces asphalt mixture at lower temperatures, and reduces environmental pollution as well as ageing and stiffness of the asphalt binder. This study is aimed at investigating the use of two techniques to decrease environmental pollution, save energy and costs, and improve asphalt mixture performance: WMA technique and RAP materials in asphalt mixtures. The Para-fiber additive was also employed in different values. With respect to the RAP, the use of virgin aggregates was decreased. To compare and evaluate the mechanical performance of asphalt mixtures, tests including resilient modulus, dynamic creep, indirect tensile strength, indirect tensile fatigue, and boiling water tests were conducted. According to the results, using RAP led to an increase in resilient modulus of mixtures and improved the resistance against permanent deformation. Also, by the addition of Para-fiber, the fatigue life of asphalt was improved. Moreover, according to the results of the fatigue test, it was shown that by the addition of RAP, the fatigue life of mixtures was decreased remarkably, yet it was enhanced by using Para-fiber.