This report describes research in 2004 and 2005 aimed at improving the means by which the durability of bitumens manufactured or imported to New Zealand for use in chipseals is assessed and monitored.
Bitumen durability refers to the long-term resistance to oxidative hardening of the material in the field. Although, in-service, all bitumens harden with time through reaction with oxygen in the air, excessive rates of hardening (poor durability) can lead to premature binder embrittlement and surfacing failure resulting in cracking and chip loss.
Some means of assessing durability by accelerating the process in the laboratory is necessary. However, no internationally accepted ‘standard’ exists for bitumen durability, as for some other bitumen tests (eg penetration).
Keywords: bitumen, chipseal, durability, oxidation, pavements, roads, testing