Evaluation of a Modified Local Asphalt Binder Incorporating Hybrid SBS and Nanomaterials for Enhanced Physical and Rheological Properties

One of the most frequent types of asphalt pavement failure is rutting. Pavement failures can be greatly reduced or delayed by improving asphalt binder’s characteristics. High-performance pavements require high-quality asphalt that contains composite modifiers. In this study, a combination of polymer and nanoparticles was used to modify a local 40/50 penetration-grade asphalt binder (PG 70-16). Fixed dosages of carbon nanotubes (CNTs), nano silica (NS), styrene-butadiene-styrene (in both granular (SBSG) and powdered (SBSP) forms) were applied individually and in hybrid combinations. A series of physical, rheological tests, field emission scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS) were used to examine unmodified and modified asphalt binders to evaluate improvements in key performance characteristics. As well as, the comparison of the effectiveness of SBSG and SBSP in asphalt binder modification. According to the results, the additions improved viscosity, raised the softening point, penetration index, and flash point, while penetration decreased. High-temperature improvements were validated by DSR results. While BBR showed changes in low-temperature grades. The improvements were attained by increasing high temperature grade as follows: 4% SBS raised the grade to PG 76-16, while CNTs and hybrid of nanomaterials increased it to PG 82-16, NS alone gave PG 70-16. PG 88-10 was attained by the triple hybrid of polymer with nanomaterials. FESEM results revealed improved compatibility and dispersion, particularly in composite modified asphalt binders of (SBSP + NS + CNTs). SBSP outperformed SBSG in most of the tests, enhancing rutting resistance, penetration, softening point, and fatigue performance due to its stronger elastic polymer network.