"…a better way to convert our waste, including non-biodegradable plastic waste, into a high-value construction material."
Scientists at a UK university have developed a more sustainable method of laying roads and pavements, using the sort of materials that the legend of Dick Whittington wasn’t hoping to find when he ventured into London all those years ago: organic bin waste like decomposed food, paper and plastic. Aston University in Birmingham has engineered a highly viscose fluid that it has said closely replicates the fossil fuel-based bitumen that is traditionally used in making highways and byways, by applying a process that breaks down mixed household waste into a sticky black fluid that is ideal for road surfacing. This announcement comes as the French tyre manufacturer announced its own eco strategy.
The university’s European Bioenergy Research Institute (EBRI) and the Aston Institute of Materials Research (AIMR) created the sustainable approach and has already had enquiries from Birmingham City Council and Highways England, the government department that operates and maintains England's major roads. The bio-bitumen is produced using a process called pyrolysis, which occurs by placing organic waste in a reactor and heating it to around 500°C in the absence of oxygen.
The @AstonUniversity researchers said that adoption of the bio-bitumen could help rescue some 7.7 million tonnes of biodegradable waste from landfill sites every year, leading to a product that uses at least four times more varieties of waste (known as waste fraction) than the plastic road concepts that is being trialled by some UK councils. With plastic roads, waste plastic such as bottles and bags are broken down into a material that is reportedly stronger and more robust than traditional asphalt – one of the biggest sources of carbon emissions in road construction.
“If the product is largely produced and widely applied, we would have a better way to convert our waste, including non-biodegradable plastic waste, into a high-value construction material, instead of current disposal practices such as landfill and incineration – both of which are harmful to the environment,” said Dr Yang Yang, study author and EBRI researcher in biomass pyrolysis.
His colleague and AIMR researcher, Dr Yuqing Zhang, was clear of the material’s benefits over traditional and plastic asphalt. “We’re eager to make progress and demonstrate how this material could spark a sharp decline in the pollution created in the production of asphalt. Plastic roads only use a relatively small amount of plastic, and still rely heavily on traditional asphalt.”
In related news, the bio-bitumen development comes following an announcement from Michelin, one of the world’s largest producers of road tyres, of its intention to use 80% sustainable materials in all of its tyres by 2048. Also committing to recycling 100% of its tyres by the same year, the French company said that that the two approaches would save 33 million barrels of oil a year. However, it's fair to say that in an industry where change in this area gathers pace quickly, 30 years seems like a long way away.
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