The Influence of Short-Term Aging on Bitumen Properties

The short-term aging properties of neat bitumen were investigated using the rolling thin film oven test (RTFOT) to simulate aging during mixing, compaction and laying of asphalt mixtures, though the actual time of short-term aging in the field varies depending on haulage distances or paving times. The empirical tests, which include penetration and softening points, were conducted to ascertain the binder consistency. The RTFOT was conducted at 1630C for 70min, 85min, and 100min for bitumen 80/100-penetration grade. Results from the study indicated that aging resulted in oxidation of the bitumen with increase in the stiffness of the binder. It was observed that aging increased the viscosity, decreased the binder penetration and increased the softening point of the neat bitumen. The results from the study also indicated that the magnitude of the short-term aging depends on the binder source, and aging time, as with longer aging time, the binder hardness and viscosity increases, thereby decreasing the penetration and increasing the binder softening point