Austroads: Transport Research and Trends

The use of reclaimed asphalt pavement (RAP) in new asphalt mixes is a common practice in Australia and New Zealand due to its many benefits. RAP contents are typically about 10–20% but higher contents can be used, if the effect of the aged binders present in RAP is accounted for. Rejuvenators can be used to soften the hardened binders which are present in RAP, and are therefore considered an essential component for producing high-content RAP mixes.

Although Australian and New Zealand asphalt producers acknowledge the importance of rejuvenators (in particular when producing high RAP mixes), rejuvenators are not commonly used due to the lack of specifications/guidelines that can evaluate the potential performance of rejuvenators when used in RAP mixes. To address this issue, Austroads has developed a rejuvenator evaluation protocol. In this protocol, rejuvenators are evaluated as part of binder blends, and their short/long-term ageing resistance is assessed to ensure their performance at the production stage as well as during service in the long term.

This webinar with Young Choi, Robert Busuttil and Robert Urquhart presents the proposed protocol and its development work. The development work involved a literature review into international rejuvenator specifications and research studies, in particular those which investigated the effect of rejuvenator properties on the properties/ performance of asphalt binders and mixes.

The development work involved obtaining feedback from Austroads technical group members and international experts. These studies were conducted to ensure that the evaluation protocol is robust and practical.

The webinar also covers a plan for future validation studies which will ensure that the protocol is suitable for use in Australia and New Zealand.