New life for tyre recycling by-products
The European construction industry consumes about 120,000 tonnes of new steel fibres every year for use as reinforcement in concrete. About twice this amount of steel fibre is produced, annually, as a by-product from the recycling of end-of-life tyres.
Most of this tyre wire is too contaminated with rubber to be recycled by steel mills, but is prevented by legislation from being landfilled and is being stockpiled awaiting cost-effective disposal solutions.
Researchers in the Department of Civil and Structural Engineering have collaborated on projects with industry partner TWINCON Ltd to develop uses for by-products of tyre recycling, particularly focused on concrete.
TWINCON Ltd has developed techniques and a unique facility that turns low value tyre wire into a high value product to replace virgin steel fibre reinforcement in concrete. Recovering steel fibre from tyres uses only about 5 per cent of the energy that is needed to manufacture it from virgin wire, a huge environmental saving.
TWINCON Ltd and University researchers are now working on a new prototype. Fibre cleaning and integration machines have been developed to turn polymer fibres from end-of-life tyres into usable construction material, which is now being tested in various applications. This is the first time that this kind of material has been used to reinforce concrete and, as well as reducing waste, the findings could help increase the safety of constructed infrastructure in the event of fire.
The aim is to commercialise the research that has been carried out at Sheffield and develop industrial processes to make the material available on a larger scale.
Harris Angelakopoulos, Managing Director at TWINCON, said: "We are very selective about who we work with. Sheffield has experts and state-of-the-art lab facilities; it’s the perfect environment for developing new ideas.
"The construction industry is the largest consumer of raw materials and thus has a huge environmental responsibility. Successful adoption of recycled materials, TWINCON’s Reused Tyre Steel and Polymer Fibres, will contribute towards achieving ambitious carbon targets as well as accelerate the transition towards a circular economy."