National specification for crumb rubber binders in asphalt and seals

Crumb rubber binders have been used to construct sprayed seals in Australia for many decades but have not been utilised in asphalt in the past. Due to the lack of crumb rubber binder grades in the Australian national polymer modified binder (PMB) specification (ATS 3110), two Austroads jurisdictions have conducted research to develop specifications for crumb rubber binders that are suitable for use in asphalt. These specifications have been based on US testing protocols rather than ATS 3110-specified tests. This report describes experimental work conducted to propose ATS 3110-related specification limits for a crumb rubber binder which is representative of the type of binder trialled by Austroads jurisdictions in asphalt, as well as a blend of C170 bitumen and 9% w/w crumb rubber (for use in sprayed sealing applications). The report also includes the results of asphalt performance tests which were performed to determine how the level of crumb rubber in a binder affected asphalt mix performance. The report includes literature reviews into a number of crumb rubber related areas and the results of a survey of Australian crumb rubber manufacturers into the properties of the material they produce. Join us for a webinar on Wednesday 6 October 2021 with lead author Robert Urquhart. No charge but registration is essential. Can’t make the live session? Register and we’ll send you a link to the recording. Register now!