Influence of Warm Mix Asphalt Additives on the Physical Characteristics of Crumb Rubber Asphalt Binders

Abstract

This investigation is centered around the application of warm mix asphalt (WMA) technologies to address workability concerns linked to rubberized asphalt binders. The primary aim of incorporating crumb rubber (CR) and WMA additives is to establish a robust paving method that fosters energy conservation, efficient waste management, noise reduction, and improved overall performance. The current study aims to comprehensively characterize and differentiate the physical attributes of rubberized asphalt binders by employing three distinct WMA additives: Sasobit, Cecabase RT and Rediset WMX. These additives are introduced into eight unique asphalt binders. Laboratory assessments are carried out to evaluate the workability and physical properties of these binders. The evaluation encompasses penetration, softening point, penetration index, penetration viscosity number, storage stability, ductility, viscosity, and stiffness modulus analyses. The findings indicate that the rubberized asphalt binder enhanced with Sasobit demonstrates the highest levels of both hardness and softening point in comparison to asphalt binders supplemented with alternative WMA additives. The evaluation of storage stability underscores the satisfactory stability across all modified asphalt binders. Both the unmodified and modified binders meet the requirements stipulated by the ductility test; the rubberized asphalt binder modified with Rediset falls short. The rubberized asphalt binder improved with Sasobit displays the most notable enhancement in workability. Furthermore, the blend of crumb rubber and Sasobit binder reveals the highest stiffness modulus values under conditions of intermediate and high temperatures with 1.88 and 0.46 MPa, respectively. In summation, the rubberized asphalt binder incorporating crumb rubber with Sasobit showcases superior improvements in both stiffness and workability compared to counterparts modified with Cecabase RT and Rediset WMX.