Sustainability has been an issue of growing import in the UK and around the world, as more and more members of the public are made aware of the dangers presented by the ongoing climate crisis. The recent COP26 summit in Glasgow saw member states re-avow their commitment to net-zero emissions targets by 2050, while wider questions about the sustainability of non-recyclable products abound.
Car tyres are one such product which present a real ecological issue for local councils and national waste infrastructure. New sustainable tyre designs are on the way, but what can we do with older tyres reaching the end of their life?
What Makes a Car Tyre?
Car tyres are a sophisticated invention, using clever material engineering to create a durable, resilient wheel with adequate traction for long distances. The tyre rubber itself is a combination of natural and synthetic rubbers, mixed to confer different benefits to the overall tyre. The resulting compound is relatively oil-rich, and non-biodegradable. This compound is made rigid by a ‘carcass’ of rubber-coated textile or steel weave, with the whole tyre mounted on a steel rim for rigidity.
If you as an individual are looking to throw your old car tyres away, you will likely do so at your local waste and recycling centre. In the past, whole tyres would end up taking up space at landfill sites – but a series of legislative changes in the early 2000s prohibited tyres from ending up at landfill, spurring new efforts to recycle.
Today, if you take your old tyres to a tip, they will be moved on to a recycling plant. The plant will break down the tyre into its constituent parts, removing the metal rim then shredding in order to remove any metal weave from the rubber itself. The rubber is then granulated, creating a rubber ‘crumb’ which can be used to manufacture new products.
Re-Use in Construction Materials
One of the more effective ways in which car tyres can be recycled was only a relatively recent discovery, with considerable benefits beyond the environmental aspect. Recent scientific research and experimentation has found that granulated tyre rubber, or ‘crumb’ can act as an effective aggregate in concrete and asphalt, in place of the more commonly used sand. The research indicates that rubber crumb poses no difficulties to laying concrete, and can in fact confer additional benefits in the form of ductile strength and impact resistance.
Trials have been taking place globally with regard to the use of tyre rubber in construction, but the UK has seen recycled tyres literally paving the way; Lancashire council were among the first in the nation to lay a road using asphalt comprising recycled tyre rubber, setting the stage for a sustainable future with regard to road infrastructure.