Performance evaluation of asphalt modified with municipalwastes for sustainable pavement construction

Abstract

The severe hot temperature and high traffic loadings in the Kingdom of Saudi Arabia (KSA) are causing distress in flexible pavements within a few years of service. Secondly, the conventional bitumen extracted from Saudi oil refineries have a performance grade of 64-10 (PG 64-10), which does not meet the SuperPave performance grade requirement for most of the KSA's regions. In order to improve the performance grade of bitumen, different percentages of municipal wastes (plastic and crumb rubber) were used as bitumen additives. The performance of bitumen at low, intermediate, and high temperatures was evaluated. This is important as the waste production is rising significantly due to the fast urbanization and high population growth in the KSA. Particularly, when there are very few ways of recycling these wastes (municipal, as well as industrial), which in fact have great impact on the environment. High-density polyethylene (HDP), low-density polyethylene (LDP), and crumb rubber (CR) with 5%, 10%, and 15% by weight of bitumen, were mixed with the base bitumen (PG 64-10). Rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) were used to evaluate the viscosity, rutting, fatigue, and low-temperature behavior of base and modified binders. The test results indicated that the rutting (permanent deformation) and fatigue resistance were significantly improved in modified binders due to the improvement in the visco-elastic properties.