Ground Tire Rubber Modification for Improved Asphalt Storage Stability

Approximately 27 million waste tires per year are placed in landfills, dumps, and stockpiles. This lack of appropriate end-of-life management creates health and environmental concerns. Scrap tires can be reused for fuel, agriculture, and civil engineering applications, such as a modifier for bitumen. Blending ground tire rubber (GTR) in bitumen not only solves an environmental issue by recycling tires, but their use can also result in better performing pavements. Asphalt rubber has improved rutting resistance, thermal and reflective crack resistance, and resistance to fatigue cracking. However, one main challenge to using GTR is a stability issue caused by density disparity between GTR and the base bitumen. This can cause problems during transportation and laying of pavement. The separation of GTR and bitumen can be reduced by the extrusion of a polymer additive with GTR before blending.