Influence of performance-graded binders on enhancing asphalt mixture performance with epoxy resin and crumb rubber powder

Abstract

The evaluation of asphalt mixture fatigue performance holds increasing significance in the context of asphalt concrete pavement and various polymer modifiers. This study focuses on assessing the fatigue and reflection crack performance of two asphalt types: a conventional 10 mm SMA mixture with a fixed PG grade (PG 76–22) and a modified asphalt employing SBS, available in multiple grades (ranging from PG 76–22 to PG 82–22). Additionally, this study incorporates crumb rubber powder (CRP-6%) and epoxy resin (ER-4%) into the conventional SBS-modified SMA binder, reducing conventional asphalt binder consumption and promoting the utilization of recycled waste materials. To achieve this goal, comprehensive evaluations of fatigue cracking performance were conducted on SMA mixtures through multiple stressed creep and recovery tests, Texas overlay tests, and direct tensile cyclic fatigue tests. The results reveal that the modified binder exhibited superior strain recovery and a reduced strain rate in comparison to the reference binder under creep loads at MSCR levels of 0.1 and 3.2 KPa. The findings also indicate a 19.5% load reduction in the modified asphalt mixture with PG 72–22 binders, epoxy, and CRP after 1000 cycles, compared to 39.8% for the conventional mixture with a PG 76–22 binder. Moreover, the modified mixture demonstrated significant improvements, with 3.7 times more repetitions and 3.9 times more interactions to failure at strain levels of 330 and 360, respectively. Importantly, the research highlights the superior fatigue crack resistance performance of the PG 76–28 grade mixture compared to PG 76–22, positioning it as an optimal choice for aged concrete overlay applications. In conclusion, this study contributes to the development of more durable and reliable polymer-modified SMA mixtures enhanced with epoxy and crumb rubber, facilitating the advancement of sustainable road infrastructure.