German chemical company Evonik has created a process additive to turn scrap tyres into a recycled construction material for durable roads
Road quality and durability are key concerns for the public sector. The clearly emerging demand for high-performance road construction materials to avoid potholes and cracks – and to save maintenance costs – is increasingly moving into public awareness.
Raw material costs for asphalt, and specifically for asphalt modification compounds, have increased considerably, creating another obstacle to cost-effective road construction.
Evonik is pursuing a sustainable and cost-effective approach to road construction. VESTENAMER®, the speciality chemical company’s process additive for the rubber industry, makes it possible to process rubber powder from scrap tyres to generate asphalt with rubber content.
The recycled material is mixed into road construction bitumen or asphalt to improve the quality of the mixtures and to extend the service life of road surfaces.
Frank Lindner, senior business manager for VESTENAMER® said: “The market for elastomer-modified, i.e. rubber-containing, road surfaces has been growing in Europe over the past years as well.
“The positive properties are obvious since the material significantly reduces cracking, ruts and potholes in the road surface, which in turn extends road service life.”
Thomas Engenhorst, sustainability strategy manager in the Resource Efficiency Segment of Evonik commented: “Reusing recycled tyres secures valuable resources.
“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 a test track in the German town of Paderborn, the local road Detmolder Strasse was resurfaced in 2012 in compliance with the objectives of the EU Waste Directive. 50% of the new asphalt mixture consisted of milled material–asphalt granulate–from the old road. The new mixture formulation also included rubber powder and VESTENAMER®. For every 100m of track, some 80 scrap tyres were turned into an elastomer-modified road surface, along with recycling the old asphalt.