Old tyres make for stronger concrete
For some time crumbs of rubber from ground-up discarded tyres have been used to produce a more resilient form of asphalt. Researchers from the University of British Columbia are taking things in a different direction, however, by using polymer fibres obtained from old tyres to make concrete stronger.
Added to existing concrete, the stretchy fibres bridge tiny cracks as they form, keeping them from becoming bigger. In-lab tests, concrete with the added fibres was found to be over 90% more resistant to problematic cracks compared to conventional concrete.
What’s more, the fibres only need to make up 0.35% of the total mixture.
Not only could the technology help keep tyres from ending up in landfills, but it should also reduce the number of times that concrete structures have to be replaced. Given that cement production is a major source of carbon dioxide, the less often the material has to be used, the better for lessening the emission of greenhouse gases.
Led by civil engineering professor Nemkumar Banthia, researchers used the fibre-reinforced concrete to resurface the steps of UBC’s McMillan building last month. Utilisng sensors embedded in the concrete, they are now monitoring it for factors such as strain and cracking – so far, the results are promising.
A paper on the project was recently published in the journal Materials and Structures.