Engineers from Australia’s RMIT University have developed a manufacturing process to make concrete using car tyres.
The recycled cement can replace 100 per cent of conventional aggregates – such as crushed rock and gravel – and the researchers claim the greener and lighter concrete can significantly reduce manufacturing and transportation costs.
Small amounts of rubber from tyres have already been used to include in concrete aggregates, but attempts to replace all aggregates with rubber have produced weak concrete – until now.
Mohammad Momeen UI Islam, the lead author of the study from RMIT’s School of Engineering, said the findings debunked a popular theory on what could be achieved with recycled rubber in concrete.
“We have demonstrated with our precise casting method that this decades-old perceived limitation on using large amounts of coarse rubber particles in concrete can now be overcome,” said Islam.
He explained that the new technique involves using differently designed casting moulds to compress the coarse rubber aggregate in fresh concrete which improves the material’s performance.
Professor Jie Li, the co-author of the study, said that replacing traditional concrete with the one they developed using used tyre rubber can reduce resource consumption and address the environmental challenge of what to do with discarded car tyres.
In Australia, used tyres cannot be exported, which makes research and development for new methods of recycling important.
An estimated 1.2 billion tyres will be disposed of globally by 2030 and using them in concrete has advantages.
“This would benefit a range of developments including low-cost housing projects in rural and remote parts of Australia and other countries around the world,” Li added.
