RMIT University engineers in Australia have collaborated with the Tyre Stewardship Australia to discover that crumb rubber from end-of-life tires can provide a sustainable solution to UV protection for roads, the university says. The organizations found that when rubber from end-of-life tires is blended with a mixture of asphalt, the road is more UV-resistant and withstands traffic loads. The organizations also say that this finding could help governments save millions on road maintenance annually.

The study led by Associate Professor Filippo Giustozzi at RMIT University found that the road aging trend is actually slowed down when crumb rubber (recycled from scrap tires) is added to the top layer of a road. Results from the study were published in the Journal of Cleaner Production.

“This acts so effectively as a sunscreen for roads that it actually makes the surface last twice as long as regular bitumen (asphalt),” Giustozzi said in a university release.

RMIT is one of the few universities in Australia to have a UV machine for asphalt studies, which can simulate weather-related aging and is usually used for testing outdoor furniture paints, the university says. The study found that after a month and a half of continuous exposure to the UV machine – equivalent to about a year of Melbourne’s UV radiation – changes happened in the asphalt’s chemical and mechanical properties.

Giustozzi said asphalt mixed with the high concentration of crumb rubber from recycled tires showed 50% less UV damage compared to regular bitumen. While using more rubber was better in terms of UV resistance, Giustozzi said it was also important to balance this with mechanical performance.

For Australia, incorporating recycled rubber into asphalt not only offers sun protection but provides a promising sustainable solution to Australia’s end-of-life tire problem, since end-of-life tires in the country have been subject to an export ban since December 2020, the university says.