Effects of Ground Tire Rubber and Trans-Polyoctenamer on the Rheological Properties and Aging Response of Asphalt Binders

Abstract The sustainable management of end-of-life tires represents a persistent environmental challenge, with declining recycling rates leading to increased landfilling and associated ecological risks. This research aligns with the conference theme by presenting a waste-to-resource pathway that transforms ground tire rubber (GTR) into a high-value modifier for asphalt binders, simultaneously addressing waste diversion and infrastructure performance needs. With transportation agencies increasingly specifying higher performance grades such as PG 82 − 22 for demanding applications, this study investigates whether elevated dosages of GTR can serve as a primary, sustainable modifier to meet these specifications. Through a comprehensive experimental program, base binders (PG 64 − 22 and polymer-modified PG 76 − 22) were modified with GTR contents ranging from 10% to 15% and 3% to 8%, respectively, both with and without the compatibility agent trans-polyoctenamer (TOR). Advanced rheological testing using DSR and BBR coupled with chemical characterization via FTIR spectroscopy, evaluated performance and aging characteristics. Results demonstrate that a 15% GTR dosage successfully elevates the high-temperature grade of a base binder from PG 64 to PG 82, achieving the target specification while maintaining critical low-temperature performance. The incorporation of GTR significantly enhanced rutting resistance and elastic response, with the hybrid use of TOR further improving binder compatibility and long-term durability. Critically, this approach can increase the consumption of recycled tire rubber in asphalt by over 50% compared to conventional practice. This study concludes that high-dosage GTR modification presents a technically viable and environmentally strategic method to produce superior asphalt binders. It provides a direct, scalable pathway to enhance the circular economy for scrap tires, reduce reliance on virgin polymer modifiers, and support the development of sustainable, high-performance infrastructure. The findings offer actionable insights for policymakers, material developers, and transportation agencies seeking to integrate waste recycling objectives with advanced engineering performance.