Characterization of Asphalt Pavement Materials in the State of Qatar

The state of Qatar is experiencing tremendous economic growth, and traffic loading has increased rapidly as a consequence of the need to increase road transport efficiency. This study was initiated to evaluate the properties of asphalt pavement materials and make recommendations for materials and test methods that can be used to build long-lasting roads that are necessary to support economic growth. Many tests were conducted to evaluate the physical, chemical, and mechanical properties of asphalt pavement materials. Some of these results will be valuable as the state of Qatar moves toward mechanistic-empirical design. The imported aggregates referred to as gabbro were found to have better resistance to degradation under mechanical forces and better skid resistance in comparison to the local limestone aggregates. However, the surface energy results reveal that gabbro has less resistance to moisture damage than the limestone aggregate. The dynamic mechanical analysis of the mixtures demonstrates the benefits of using modified asphalt binders instead of the current unmodified binders used in the country. The results of the mechanical tests that were conducted on extracted field cores show that good resistance to permanent deformation can be expected under traffic; however, these mixtures could be prone to fatigue cracking, given the low asphalt binder used in these mixtures.