Wisconsin county uses recycled materials in highway repaving project
Eau Claire County, Wisconsin, is using recycled materials to repave its roads. The county began using the materials last year on a rural road in Augusta.
According to local news reports, Highway Commissioner Jon Johnson says the new method cuts the cost of repaving in half. Rather than removing material and hauling in new product, the county began grinding the road surface and combining it with an oil-based substance.
The county’s goal is to repave more than 78 miles of road using the recycled material in the next five years.
Johnson says the county will save more than $7 million over 10 years through recycling.
Johnson says that using recycled materials also allows the county to increase how much road is improved per year.
Previously, Eau Claire County was replacing eight to 10 miles of road per year, and since using recycled materials, that number has jumped to 21 miles.
The county is currently using processing equipment that is contracted out, but it plans to purchase its own equipment in the future.
Study claims tire fiber strengthens concrete
University of British Columbia (UBC) engineers in Vancouver have developed a type of concrete designed to be more resilient using recycled tires.
The researchers experimented with different proportions of recycled tire fibers and other materials used in concrete before finding a working mix, which includes 0.35 percent tire fibers, according to researcher Obinna Onuaguluchi, a postdoctoral fellow in civil engineering at UBC.
Asphalt roads that incorporate rubber “crumbs” from shredded tires exist in the U.S., Germany, Spain, Brazil and China. But using the polymer fibers from tires can potentially improve the resilience of concrete and extend its lifespan.
“Our lab tests showed that fiber-reinforced concrete reduces crack formation by more than 90 percent compared to regular concrete,” Onuaguluchi says of the results. “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.”
UBC civil engineering professor Nemkumar Banthia, who supervised the work, says the environmental and industrial impact of the research is crucial.
“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,” says Banthia.
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 and looking at development of strain, cracking and other factors. So far, the results support laboratory testing.