Toughening characteristics of plastic fiber-reinforced hot-mix asphalt mixtures

With the performance limitation of a conventional hot-mix asphalt mixture, the structural integrity of that is highly needed to be enhanced to increase the fatigue life of the mixture. Various geosynthetic alternatives have been widely utilized, such as geogrid, geotextile, or geomembrane layers at the bottom the mixture or on the top of a subgrade to improve the structural integrity of a hot-mix asphalt pavement system. Although reinforcing effects of such interlayers has been reported with some improvements in hot-mix asphalt pavements’ performances, such as mitigating rut or delaying reflective cracks; however, such alternatives do not enhance toughness, tensile strength, or shear strength of the hot-mix asphalt mixture itself due to that the interlayers are usually installed in between two layers in a pavement system and those interlayers do not mix with hot-mix asphalt mixtures. A new plastic fiber-reinforced hot-mix asphalt mixture was proposed in this study to provide more enhanced structural integrity of the mixture not only at the bottom of the mixture but also within the mixture. The developed mixture in this study led to significant enhancements in phenomenological toughness and fatigue life of that at least 1.5 times higher than those for conventional hot-mix asphalt mixtures as resulting from indirect cyclic fatigue tests in loading-control modes and four-point bending beam tests in displacement-control modes.