Abstract

The empirical test methods of asphalt cement like softening point and penetration can only give limited insight into the property of the binder, advanced test methods are used in the present investigation to characterize the effects of ageing on the rheological and physical properties of asphalt cement. In this study, a specific combination of physical, rheological, and surface free energy testing has been implemented to categorize the influence of ageing on binder properties. Asphalt cement obtained from Doura oil refinery was subjected to ageing with the aid of Thin Film Oven Test (TFOT) apparatus, the binder experienced a temperature of 163 °C for 5 hours. All the testing was conducted on samples before and after ageing. It was observed that surface free energy decreased by (76 and 7.8) % after practicing ageing when tested by Sessile Drop and Wilhelmy plate methods respectively. However, the stiffness modulus increases by 26.6 % after ageing. The penetration and ductility decreased by (13 and 12) % respectively while the softening point increased by 11 % after ageing. On the other hand, the penetration index (PI) and the penetration viscosity number (PVN) have improved by (74.6 and 10.8) % respectively after ageing. It was recommended that asphalt cement should practice the physical, rheological, and surface free energy testing before a decision can be made of its suitability to be used for pavement under a specified environmental condition.