The asphalt pavements in hot and arid climatic regions, like Iraq and many parts of the Middle East, are subject to a variety of extreme thermal gradients, long-term oxidative aging, and short-term moisture intrusion. All of these conditions create stress on asphalt mixtures that lead to accelerated ruts, stripping, and structural failure over time. At the same time, as high-quality natural aggregate becomes less available, this has led to increasing demand for sustainable high-performance options for use in asphalt production. Recycled Concrete Aggregate (RCA) has become an excellent solution to this problem for both environmental and availability reasons. Unfortunately, the unique properties of RCA (e.g., high porosity, adhered mortar, and high-water absorption) negatively affect the density of asphalt mixtures and increase the susceptibility of RCA to moisture damage. In addition, High Density Polyethylene (HDPE) and other forms of plastic modifier materials have the potential to significantly improve the stiffness of RCA asphalt mixtures, reduce the susceptibility to temperature changes, and provide increased resistance to deformation at high temperatures.