Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff Lauren Boglebom here with a classic brain Stuff episode. In this one, we talked about a technological process that was just getting started back when this episode originally published in using recycled plastics in paving and fixing up roads. Since then, research and rollout have continued, but here are
the basics, Hey brain Stuff, Lauren Vogelbaum here. A few years ago, engineered Toby McCartney was working in southern India with a charity that aided pickers who worked at landfill sites harvesting reusable items and selling them. McCartney discovered that the plastic waste they retrieved was being put into potholes and roads, dused with gasoline and set a fire. When the plastic melted into the holes and then hardened, it filled them. When McCartney returned to Scotland, he told two
of his friends about what he had seen. As one of them, Gordon Reid, were halls, they decided that it would work better to use plastic waste to create a new type of materials specifically designed for use in roads. After a year of research, they developed a method for transforming a mix of industrial and consumer plastic waste into pellets of a new material that could replace bitumen, the oil based ceiling material that holds asphalt together in roads.
Since Reid's company, Mcgreeber started operations in April of the company's recycled plastic road building material has been used to build roadways in places ranging from Australia to Dubai. A Reid says, we've got roads on every continent and we've had interest from round about fifty countries in the world. The company currently is having discussions with the University in California about building a test road to demonstrate that its
plastics are compatible with standards in the United States. According to Read, using recycled plastic for road building sounds simple, but it actually requires a complex process to create the right material. He explained, different plastics do different things to bitterman. If you use the wrong mix, it can actually make
the bittermen more brittle. Micreeper avoids using pet bottles and other types of plastic that are easily recycled, and instead concentrates on types of waste plastic that might otherwise end up buried in the ground. Read declined to go into too much detail as so not to reveal too much about mcgreeber's proprietary process. In addition to keeping plastic out of landfills, the company says it's plastic road materials can save about a ton in carbon dioxide output for each
ton of bnemen that the plastic replaces. The company has developed different types of road building plastic four different environments. One variety is designed for roads in such places as the Middle East, where more tensile strength is needed to resist asphalts tendency to deform from heat. Another is designed to be more flexible and resist the freeze thaw cycle
in colder places such as Canada or Scotland. Read says mcgreeber's current products are capable of replacing between six and twenty of the bitumen in roads, but Read is hopeful that within two years improved versions will replace as much as a Red says that mcgreeber's plastic road materials physically bind with the bittermin which prevents it from breaking loose and getting into the environment. In the US, plastic is
already being used in road maintenance. University of Texas at Arlington, civil engineer Professor Sahoda Hussein director of the School Solid Waste Institute for Sustainability, has turned to recycled plastic as a way to solve the problem of unstable soil on highway slopes, which eventually can cause the road surface to
fail as well. He's developed a technology for taking plastic from landfills and then recycling it to manufactured giant pins that are inserted into the falling soil to stabilize it. Cousin explained via email that the recycled plastic pin quote has been successfully tested as a laterally loaded pile in different highway slope stabilization projects in the state of Texas, Iowa,
and Missouri. The Texas Department of Transportation has adopted the recycled plastic pin as one of their approved slope stabilization methods. It takes just three to four minutes to install each of the pins in the ground, so an entire unstable area can be shored up in a few days. He said. Once the pin is installed into the ground, it is less susceptible to degradation, which makes it a long lasting
solution for slope repair. Each recycled pin utilizes about five hundred plastic soda bottles at one of the demonstration sites, Hussein's research group put six hundred plastic pins into the ground, making use of some three hundred thousand plastic bottles that otherwise would have ended up in landfills. Hussaine thinks that the Chinese government's recent decision to ban imports of plastic waste for recycling could create an opportunity for US entrepreneurs
to make road materials. China imported seven hundred and seventy six thousand metric tons of plastic waste from the United States in TwixT Hussein said I am positive more and more roads will be constructed using recycled plastics, but he does note that more work needs to be done to develop new methods, including full scale testing and life cycle analysis of roads containing plastic materials m Today's episode is based on the article Recycled plastic waste creates Roads on
how stuff Works dot Com, written by Patrick J. Keiger. Brain Stuff is a production of I Heart Radio in partnership with how stuff Works dot Com, and it's produced by Tyler Klang and Ramsey. Out four more podcasts from my heart Radio. Visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows,