Australia and New Zealand produce about 510,000 tonnes of end‑of‑life tyres annually. Crumb rubber derived from end‑of‑life tyres has been used in Australia for several decades to enhance the performance of binders used in sprayed seals but prior to 2017 the use of crumb rubber in asphalt pavements was limited.
Due to the lack of crumb rubber binder grades suitable for use in asphalt in the Austroads national polymer modified binder (PMB) specification (ATS 3110), two Australian jurisdictions and the Australian Flexible Pavement Association recently developed specifications for crumb rubber binders for use in asphalt which were based on tests and testing protocols used in Arizona and California.
This webinar, presented by Robert Urquhart, focuses on the outcomes of an Austroads research project which investigated whether the crumb rubber binders that were trialled in asphalt could be specified in terms of the tests and testing protocols used to specify other types of PMBs in the Austroads national PMB specification. Specification requirements have also been proposed for a binder containing 9% crumb rubber by weight which could be used in sprayed sealing applications.
The webinar also discusses the results of laboratory asphalt performance tests which investigated the effects of the amount of crumb rubber in a binder on asphalt performance.