New use for scrap tyres

Placing shredded tyres on top of -- rather than in -- landfills can save money and benefit the environment, researchers from the University of Illinois say.

Timothy Stark, a professor of civil and environmental engineering at the University of Illinois at Urbana-Champaign, and Krishna Reddy, a professor of civil engineering at the University of Illinois at Chicago, recently evaluated the use of shredded tyres as a drainage material in waste-containment systems.

Shredding tyres into chips roughly four inches by six inches, they report, offers a simple and cost-effective way of providing drainage for modern landfills, remediating older landfills, and disposing of mountains of scrap tyres.

Nearly 280 million tyres are discarded annually in the United States. Piles of worn-out tyres can become eyesores and breeding grounds for mosquitoes. In landfills, intact tyres can collect methane (produced by decomposing waste) and create potential fire hazards. Over time, these tyres can work their way to the surface, where they can damage liner covers and cause increased leachate production that could contaminate groundwater.