Abstract
The use of polymers to modify asphalt binder properties in road paving has been increased over the past few decades, producing asphalt mixes that can withstand the growth in traffic load concurrent with development. Therefore, the use of modified asphalt binders has become increasingly popular in recent years to enhance the properties of pavement roads by incorporating various materials, including sustainable ones. This study was conducted as part of a larger study for enhancing asphalt binder properties by using 1%, 2%, 3%, and 4% of sasobit (S) as a warm mix asphalt additive and 1%, 2%, 3%, and 4% of low-density polyethylene (L) as sustainable materials and the mix combination (MC) of both of them. The performance of the treated bitumen was evaluated using conventional tests, including penetration, softening point, and ductility, to assess the physical properties of the mixtures. More advanced tests, including a dynamic shear rheometer (DSR) and a rolling thin film oven test (RTFOT), were conducted. The results show that 4% of Sasobit and 1% of LDPE achieved the optimal values, which significantly enhances the performance of asphalt binders, offering a synergistic blend of sustainability and functionality. LDPE improves the binder’s elasticity and resistance to deformation, while Sasobit lowers mixing and compaction temperatures, boosting workability and energy efficiency. Their combination increases the softening point and reduces penetration and ductility, indicating better high-temperature performance. Viscosity is notably reduced, facilitating easier handling and mixing. Moreover, Sasobit enhances the binder’s resistance to thermo-oxidative aging, with improved ductility retention and thermal stability. The study concluded that using Sasobit and LDPE results in high-performance and durable asphalt mixes that may be highly resistant to permanent deformation and temperature susceptibility.