‘Tyre roads’ clock up early sustainability boost

Early indications from a trial using tyre crumbs to pave roads show rubberised asphalt performs better than traditional treatments in both hot and cold weather.

According to Lance Malburg, county highway engineer with the Dickinson County Road Commission in Michigan, USA, lab experiments show the performance of the materials has improved after two winters of a 10-year trial. ‘Our hopes are that this project will demonstrate that rubberized asphalt not only is smoother, quieter, and longer lasting than traditional asphalt, but can also be made economically,’ he says.

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) backed a project on a stretch of road in Dickinson County whereby three sections of road were paved for comparison and testing: conventional hot mix asphalt base top layer; engineered crumb rubber hot mix asphalt base with conventional top layer; and hot mix base with engineered crumb rubber as both the base and top layers. The work was completed in June 2019.

Lab experiments show the performance of the materials has improved, with more resistance both to rutting during hot temperatures and cracking during cold weather. The sections will be compared, monitored for 10 or more years with scientists specifically watching for cold weather cracking resistance of the two asphalt mixes.

The project used more than 3 600 scrap tyres and won a 2019 award in Michigan for demonstrating innovation with special projects in communications, operations and collaboration.