The Australian Road Research Board (ARRB) is recommending further research into the use of passenger vehicle tyres in bitumen production.
ARRB Senior Professional Leader Guy Hand said Victoria’s Transport Department, formerly VicRoads, engaged ARRB to undertake a literature review on the subject.
“Using more end-of-life tyres in road construction is a known way to curb significant environmental challenge for Australia. The question is, how do we make that happen?,” Mr Hand said.
“One possibility is to engage the use of end-of-life car tyres.”
Most crumb rubber repurposed into Australian road construction currently comes from end-of-life truck tyres.
According to Mr Hand, truck tyres are predominantly composed of natural rubber, whereas car tyres contain a high proportion of synthetic rubber, as well as a nylon component.
“It is not well understood whether synthetic rubber will behave in bitumen in the same nature that natural rubber does,” Mr Hand said.
“No data from an Australian context is available to establish the compatibility and performance of synthetic rubber in bitumen.”
Mr Hand said the key objective of the review is to understand the current specifications of crumb rubber sourced by other road agencies, and the market availability and processing requirements of passenger vehicle tyres.
ARRB were additionally asked to identify the benefits and limitations of using passenger vehicle tyre crumb rubber as a road material in asphalt and sprayed seals.
“There are also barriers for recycling car tyres to be considered, such as economic, environmental and processing challenges,” Mr Hand said.
“With the Victorian Government’s focus on increasing the use of recycled materials in road construction, this literature review will help inform all stakeholders on the issues associated with the use of passenger vehicle tyres in bitumen.”