Researchers at the University of British Columbia (UBC) used recycled tires to develop an extra resilient concrete that could be used for buildings, roads, bridges and dams, while reducing landfill waste.
According to researcher Obinna Onuaguluchi, a postdoctoral fellow in civil engineering at UBC, the team tested different parts of recycled tire fibres and other concrete-based materials like sand and water to find the “ideal mix,” which includes 0.35 per cent of tire fibres.
The research, described in Materials and Structures, explains how asphalt roads in other countries already use ‘rubber crumbs.’ However, in this case, using polymer fibres from tires can potentially improve the resilience of concrete and extend its lifespan.
“Our lab tests showed that fibre-reinforced concrete reduces crack formation by more than 90 per cent compared to regular concrete,” said Onuaguluchi in a press release. “Concrete structures tend to develop cracks over time, but the polymer fibres are bridging the cracks as they form, helping protect the structure and making it last longer.”
UBC civil engineering professor Nemy Banthia supervised the work. He says the “environmental and industrial impact of the research is crucial.” Up to three billion tires are produced every year around the world, generating about three billion kilograms of fibre when recycled.
“Most scrap tires are destined for landfill. Adding the fibre to concrete could shrink the tire industry’s carbon footprint and also reduce the construction industry’s emissions, since cement is a major source of greenhouse gases,” said Banthia, who also is scientific director of UBC-hosted Canada-India Research Center of Excellence (IC-IMPACTS), a centre that develops research collaborations between Canada and India.
“We use almost six billion cubic metres of concrete every year,” he added. “This fibre can be in every cubic metre of that concrete.”
The new concrete was used to resurface the steps in front of the McMillan building on UBC’s campus in May. Banthia’s team is tracking its performance using sensors embedded in the concrete, looking at development of strain, cracking and other factors. So far, the results support laboratory testing that showed it can significantly reduce cracking.