Effects Of Laboratory Short-Term Ageing On Bitumen Properties

Abstract

The fundamental parameters affecting e.g. durability of asphalt mixtures are their properties after ageing. Generally, ageing is quantified into two stages namely; short-term and long-term ageing. The aim of this paper is to understand the rheological and chemical properties of different bitumen subjected to various combinations of extended laboratory short-term ageing conditions. Two bitumen with the same grade (80/100 pen) from two sources, and one 60/70 pen bitumen were used in this study. The short-term ageing procedure was performed using the standard procedure for rolling thin film oven (RTFO) test, but with varying combinations of temperature and duration. The rheological properties of short-term aged bitumen were evaluated using the dynamic shear rheometer, viscometer, and Fourier transform infrared spectroscopy. Viscosity result indicated that the increment of ageing duration and time linearly increases bitumen viscosity. However, as the temperature rises, the viscosity difference is smaller.Based on the temperature sweep test, further laboratory ageing than the standard RTFO will not be severe enough to alter the performance grade of stiffer bitumen, except for the higher part of the ageing condition. The G* ageing indices indicate that the effects of oxidative ageing becomes more severe as the ageing duration and temperature progresses but there is no obvious trend found between different bitumen. While the carbonyl and sulfoxide indices increases eveidently with ageing severity.