Austroads: Transport Research and Trends

Polymer modified binders (PMBs) are used in road construction to provide better performance than unmodified bitumen. As these materials consist of multiple components (i.e. bitumen, polymer and performance additives) the different components in a PMB can separate out, or segregate, when PMBs are stored hot before use in road construction.

The Australian PMB specification (Austroads ATS 3110) currently includes segregation tests (ATM 108) to determine whether the components in a PMB will segregate during hot storage. ATM 108 tests were developed considering current generation PMBs containing a single polymer type, but may provide misleading results if they are used to characterise next generation PMBs containing multiple polymer types. This webinar will summarise the outcomes of an Austroads project which developed a new segregation test (ATM 104) which is suitable for use with both current and next generation PMBs.

The webinar covered:

• Issues with the current ATM 108 test for characterising PMBs containing multiple polymer types
• The learnings obtained from a literature review of Australian and overseas segregation tests which were used to develop a suitable test to characterise the segregation properties of current and next generation PMBs
• The results of laboratory studies which investigated the sensitivity of the new test to segregation in current and next generation PMBs.

The webinar was presented by Dr Robert Urquhart and Robert Busuttil, who also answered attendee questions during the session.