Millions of roads throughout the United States are built with asphalt that deteriorates over time. Now, researchers at the University of Missouri are using recyclables, including plastic waste, as a sustainable solution to repair America’s broken road system.
In collaboration with the Missouri Department of Transportation (MoDOT), researchers from the Mizzou Asphalt Pavement and Innovation Lab (MAPIL) recently created a real-world test road using recycled materials such as scrap tires and plastic waste along a stretch of Interstate 155 in Missouri. Bootheel.
By increasing the sustainability of asphalt mixtures, this new method will help reduce the amount of material going to landfills or leaking into the environment, said Bill Buttlar, director of MAPIL.
“Missouri is the Show-Me State, so we have a pragmatic view,” Buttlar said. “The science can be thorny and difficult, but we are up to the task. We are excited that while our method is complex in the lab, it is simple to implement in the field, so it is easily adaptable, scalable and cost-effective to incorporate. in many types of road environments.”
The I-155 project takes the group’s old road test, which was laid out on a stretch of Stadium Boulevard in Columbia, Missouri, one step further. Instead of testing just four different types of recycled materials, the I-155 project will evaluate the real-world effectiveness of nine different types of recycled materials in making asphalt pavement. These include three different types of polyethylene (PE)—a material commonly found in plastic grocery bags—and ground rubber, which is a newer method of disposing of scrap tires. .
“These projects give us an opportunity to deliberately build the next generation of roads with these materials not as a type of linear landfill, but also to help the environment while making the value of the dollars that spent on transportation infrastructure like this far into the future,” said Buttlar, who is also the Glen Barton Chair of Flexible Pavements.
MU is at the forefront of this type of work in the US because its team answers many of the translational research questions such as durability and safety that prevent a general contractor or transportation department from adopting in this method of breaking the ground.
“We don’t just live in a laboratory,” Buttlar said. “In the field of transportation material research, we need to look at how all the different materials used to build a road—the stone, the asphalt and the recycled materials—behave in the real world. and together to build a road.”
“Asphalt melts in the heat, and if you put an additive like a plastic or rubber material, you have to put everything together with good adhesion. full level and then expose it to the elements, like different weather conditions and heavy traffic.”
MAPIL specializes in a dry process, which allows researchers to quickly add recyclables directly to the mix before placing it on the road surface.
“The shape, form and size of plastics bring different challenges in how the material flows, how it behaves and how it is mixed,” said Punya Rath, an assistant research professor at Department of Civil and Environmental Engineering working in MAPIL. “So, we did a lot of small tests for about a year before we moved to a larger scale in the field with contractors.”
One advantage of this process is that researchers can test mixtures in the field using a mobile research lab, which they developed and used for the Stadium Boulevard and I-155 projects.
“It is very helpful for the Missouri Department of Transportation (MoDOT) to have a mobile research lab on-site in the field with the ability to rapidly test samples and provide results within 24-48 hours to better understand is the process,” said Rath.
Citing environmental concerns, Buttlar said the team ensured that everything they did was within the current limits established by the Environmental Protection Agency (EPA).
“We designed the material to be able to hold or capture the environmental by-product in the highest percentage for the longest period of time. It will not be a 100% containment,” said Buttlar. “Everything built in a natural environment degrades over time, so the EPA has standards for everything, and we’re making sure we’re safe within those standards.”
Provided by the University of Missouri
Citation: Researchers driving new solutions to improve use of ‘plastic’ roads (2023, July 18) retrieved 18 July 2023 from https://phys.org/news/2023-07-solutions -advance-plastic-roads.html
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