Engineering High-Performance Asphalt Binders and Mixtures Through Micro- and Nanocoke/Polymer Hybrid Modification

Polymer modifiers and carbon-based materials have been widely proposed as potential asphalt additives to improve performance. However, limited studies have systematically compared micro- and nanocoke from different sources in combination with SBS and Elvaloy polymers or linked binder rheology with mixture performance. To address this gap, this study investigated the effects of micro- and nanodispersed petroleum and coal coke combined with SBS and Elvaloy polymers on the rheological behavior of asphalt binders and the performance of asphalt concrete mixtures. Rheological properties were evaluated by dynamic shear rheometer (DSR) testing, and asphalt concrete mixtures were tested for compressive strength and crack resistance. The modified systems were successfully used to obtain commercial polymer-modified bitumen grades: BMP 70/100, BMP 50/70 and BMP 35/50. With 1 wt.% micro coal coke and 0.1 wt.% SBS modification, a softening point of 73.7 °C and a penetration of 22.3 × 0.1 mm was observed. Micro coal coke-SBS system showed the highest compressive strength at 20 °C (3.29 MPa), while the largest crack resistance (4.39 MPa) and the best high-temperature mixture strength (0.90 MPa at 50 °C) were obtained when 0.5 wt.% nanocoke and 0.5 wt.% Elvaloy are used. These findings demonstrate that hybrid coke/polymer modification is an effective approach for enhancing asphalt performance, with micro coal coke-SBS systems providing the highest stiffness and rutting resistance, while nanocoke-Elvaloy systems delivered superior crack resistance and overall performance balance.