Obinna Onuaguluchi, UBC civil engineering postdoctoral researcher. Image credit: Clare Kiernan/UBCObinna Onuaguluchi, UBC civil engineering postdoctoral researcher. Image credit: Clare Kiernan/UBCWorn and discarded tires have found a purpose beyond clogging landfills thanks to University of British Columbia (UBC) engineers who have developed a concrete mixture suitable for use in the construction of roads, dams, buildings and bridges.

The concrete mixture, which includes traditional concrete materials (sand, cement and water), also includes 0.35 percent tire fiber from discarded tires.

Researchers believe that the addition of rubber will both extend the life and improve the resilience of the concrete.

“Our lab tests showed that fiber-reinforced concrete reduces crack formation by more than 90 percent compared to regular concrete," said researcher Obinna Onuaguluchi, a postdoctoral fellow in civil engineering at UBC. "Concrete structures tend to develop cracks over time, but the polymer fibers are bridging the cracks as they form, helping protect the structure and making it last longer."

Already being used in combination with asphalt to create roadways worldwide, it is estimated that three billion kilograms of recycled tire fiber is generated annually.

"Most scrap tires are destined for landfill. Adding the fiber 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 UBC civil engineering professor Nemkumar Banthia.

"We use almost six billion cubic meters of concrete every year," added Banthia. "This fiber can be in every cubic meter of that concrete."

Currently, the concrete has been used in the resurfacing of steps to a building on UBC’c campus in May. The research team is tracking the performance of the concrete through embedded sensors, checking for cracking and strain. The results so far suggest that the cracking has been significantly reduced.