A process additive made by German chemical company Evonik is being used to turn scrap tyres into a modern construction material for durable roads.
The process additive, known as Vestenamer, integrates rubber powder from used tires into asphalt. The recycled material is mixed with bitumen to extend the life of the road surfaces.
“Reusing recycled tyres secures valuable resources,” Evonik sustainability strategy manager in the resource efficiency Segment of Evonik Thomas Engenhorst said. “Tyres are not classified as waste, but are considered a valuable material, which may not, for example, be disposed of in landfills.
“This use eliminates the disposal question: instead of incinerating the tyres, they have another life stage in road traffic – not as part of an engine-powered vehicle, but in the form of an elastomer or rubber powder in the road surface.”
As part of the construction of a test track in the German city of Paderborn, the local road Detmolder Strasse was redone in 2012 and the new mix included rubber powder and Vestenamer. On every 100m of track, approximately 80 old tyres were turned into an elastomer-modified road surface, along with recycling the old asphalt.
Evonik’s scheme comes among growing support for recycled plastics to be used on construction. Earlier this year hard-to-recycle plastics such as computer keyboards and monitors were being crushed into Coventry roads as part of a trial to cut plastic pollution and carbon emissions.
Two roads in the city were resurfaced with material using two types of plastic pellets as a binding agent instead of bitumen, a fossil fuel traditionally used in road resurfacing.
Another section of road was resurfaced with “rubber crumbs” from old vehicle tyres. Each section will be monitored over the next few years for signs of wear and tear, but the council believes the plastic and rubber roads will be more hard-wearing than traditional asphalt, which has a high carbon footprint.
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