State of the Art Report on Ageing Test Methods for Bituminous Pavement Materials

The findings of an extensive literature review on bitumen and asphalt mixture ageing test methods are presented in the paper. The primary factors affecting the durability of bituminous paving mixtures, assuming they are constructed correctly, are age hardening and moisture damage. Ageing of the bituminous binder is manifested as an increase in its stiffness (or viscosity). Water damage is generally manifested as a loss of cohesion in the mixture and/or loss of adhesion between the bitumen and aggregate interface (stripping). Short-term ageing is primarily due to volatilisation of the bitumen within the asphalt mixture during mixing and construction, while long-term ageing is due to oxidation and some steric hardening in the field. Of the tests used to simulate short-term ageing, the extended heating procedures of the thin film oven test (TFOT) and the rolling thin film oven test (RTFOT) are the most frequently used binder methods. In regard to long-term binder ageing, the oxidative pressure ageing vessel (PAV) test and the rotating cylinder ageing test (RCAT) have shown the greatest potential. Asphalt mixture ageing is primarily limited to extended heating methods for loose bituminous material prior to compaction and combinations of extended oven ageing, high and low pressure oxidation and ultraviolet and infrared light treatments.