WEBVTT - Can We Make Roads Out of Recycled Plastic? 0:00:02.040 --> 0:00:07.120 Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff, 0:00:07.160 --> 0:00:10.240 Lauren Voge obamb here. A few years ago, engineer Toby 0:00:10.280 --> 0:00:13.000 McCartney was working in southern India with a charity that 0:00:13.039 --> 0:00:16.919 aided pickers who worked at landfill sites harvesting reusable items 0:00:16.920 --> 0:00:20.600 and selling them. McCartney discovered that the plastic waste they 0:00:20.600 --> 0:00:23.439 retrieved was being put into potholes and roads, dused with 0:00:23.440 --> 0:00:26.480 gasoline and set a fire. When the plastic melted into 0:00:26.480 --> 0:00:29.840 the holes and then hardened, it filled them. When McCartney 0:00:29.840 --> 0:00:32.040 returned to Scotland, he told two of his friends about 0:00:32.080 --> 0:00:34.879 what he had seen. As one of them, Gordon Reid, recalls, 0:00:35.120 --> 0:00:37.440 they decided that it would work better to use plastic 0:00:37.479 --> 0:00:40.640 waste to create a new type of materials specifically designed 0:00:40.640 --> 0:00:43.440 for use in roads. After a year of research, they 0:00:43.440 --> 0:00:46.280 developed a method for transforming a mix of industrial and 0:00:46.320 --> 0:00:49.280 consumer plastic waste into pellets of a new material that 0:00:49.280 --> 0:00:52.760 could replace bitumen, the oil based ceiling material that holds 0:00:52.800 --> 0:00:57.760 asphalt together in roads. Since Reid's company Mcgreeber started operations 0:00:57.760 --> 0:01:01.560 in April of sixteen, the companies recycled plastic road building 0:01:01.600 --> 0:01:04.479 material has been used to build roadways in places ranging 0:01:04.480 --> 0:01:08.319 from Australia to Dubai. Read says we've got roads on 0:01:08.360 --> 0:01:11.360 every continent, and we've had interest from round about fifty 0:01:11.400 --> 0:01:14.560 countries in the world. The company currently is having discussions 0:01:14.560 --> 0:01:17.280 with the University in California about building a test road 0:01:17.440 --> 0:01:20.319 to demonstrate that its plastics are compatible with standards in 0:01:20.319 --> 0:01:24.280 the United States. According to Read, using recycled plastic for 0:01:24.360 --> 0:01:27.560 road buildings sounds simple, but it actually requires a complex 0:01:27.600 --> 0:01:31.440 process to create the right material. He explained, different plastics 0:01:31.440 --> 0:01:34.240 do different things to bitterman. If you use the wrong mix, 0:01:34.360 --> 0:01:38.319 it can actually make the bitterman more brittle. Mcgreeper avoids 0:01:38.400 --> 0:01:41.040 using pet bottles and other types of plastic that are 0:01:41.040 --> 0:01:44.800 easily recycled, and instead concentrates on types of waste plastic 0:01:44.880 --> 0:01:47.880 that might otherwise end up buried in the ground. Read 0:01:47.920 --> 0:01:49.920 declined to go into too much detail as so not 0:01:50.000 --> 0:01:53.880 to reveal too much about mcgreeber's proprietary process. In addition 0:01:53.920 --> 0:01:56.680 to keeping plastic out of landfills, the company says it's 0:01:56.720 --> 0:01:59.520 plastic road materials can save about a ton in carbon 0:01:59.560 --> 0:02:03.080 dioxide output for each town of Benemen that the plastic replaces. 0:02:03.680 --> 0:02:06.400 The company has developed different types of road building plastic 0:02:06.440 --> 0:02:09.800 four different environments. One variety is designed for roads in 0:02:09.840 --> 0:02:12.799 such places as the Middle East, where more tensile strength 0:02:12.840 --> 0:02:15.960 is needed to resist asphalts tendency to deform from heat. 0:02:16.480 --> 0:02:19.040 Another is designed to be more flexible and resist the 0:02:19.200 --> 0:02:22.600 freeze thaw cycle in colder places such as Canada or Scotland. 0:02:22.639 --> 0:02:27.080 Read says mcgreeber's current products are capable of replacing between 0:02:27.120 --> 0:02:30.120 six and twenty of the bitumen in roads, but Read 0:02:30.200 --> 0:02:33.200 is hopeful that within two years improved versions will replace 0:02:33.200 --> 0:02:37.480 as much as Read says that mcgreeber's plastic road materials 0:02:37.480 --> 0:02:40.800 physically bind with betterman which prevents it from breaking loose 0:02:40.840 --> 0:02:44.239 and getting into the environment. In the US, plastic is 0:02:44.280 --> 0:02:47.480 already being used in road maintenance. University of Texas at 0:02:47.560 --> 0:02:51.480 Arlington civil engineer Professor Sahodat Hussein, director of the School 0:02:51.520 --> 0:02:55.400 Solid Waste Institute for Sustainability, has turned to recycled plastic 0:02:55.480 --> 0:02:58.000 as a way to solve the problem of unstable soil 0:02:58.240 --> 0:03:01.760 on highway slopes, which unually can cause the road surface 0:03:01.760 --> 0:03:05.040 to fail. As well. He's developed a technology for taking 0:03:05.040 --> 0:03:08.760 plastic from landfills and then recycling it to manufactured giant 0:03:08.880 --> 0:03:12.440 pins that are inserted into the falling soil to stabilize it. 0:03:13.080 --> 0:03:16.760 Causean explained via email that the recycled plastic pin quote 0:03:16.880 --> 0:03:20.280 has been successfully tested as a laterally loaded pile in 0:03:20.320 --> 0:03:24.360 different highway slope stabilization projects in the state of Texas, Iowa, 0:03:24.440 --> 0:03:27.799 and Missouri. The Texas Department of Transportation has adopted the 0:03:27.840 --> 0:03:31.760 recycled plastic pin as one of their approved slope stabilization methods. 0:03:32.800 --> 0:03:35.160 It takes just three to four minutes to install each 0:03:35.200 --> 0:03:37.680 of the pins in the ground, so an entire unstable 0:03:37.760 --> 0:03:40.560 area can be shored up in a few days. He said. 0:03:40.960 --> 0:03:43.120 Once the pin is installed into the ground, it is 0:03:43.200 --> 0:03:46.440 less susceptible to degradation, which makes it a long lasting 0:03:46.480 --> 0:03:50.880 solution for slope repair. Each recycled pin utilizes about five 0:03:50.960 --> 0:03:54.000 hundred plastic soda bottles. At one of the demonstration sites, 0:03:54.080 --> 0:03:57.320 Hussein's research group puts six hundred plastic pins into the ground, 0:03:57.720 --> 0:04:00.400 making use of some three hundred thousand plastic models that 0:04:00.440 --> 0:04:03.800 otherwise would have ended up in landfills. Coussine thinks that 0:04:03.800 --> 0:04:07.080 the Chinese government's recent decision to ban imports of plastic 0:04:07.080 --> 0:04:10.680 waste for recycling could create an opportunity for US entrepreneurs 0:04:10.720 --> 0:04:14.320 to make road materials. China imported seven hundred and seventy 0:04:14.400 --> 0:04:17.080 six thousand metric tons of plastic waste from the United 0:04:17.120 --> 0:04:21.240 States in two six. Hussein said, I am positive more 0:04:21.240 --> 0:04:25.080 and more roads will be constructed using recycled plastics, but 0:04:25.160 --> 0:04:27.120 he does note that more work needs to be done 0:04:27.160 --> 0:04:30.520 to develop new methods, including full scale testing and life 0:04:30.520 --> 0:04:39.400 cycle analysis of roads containing plastic materials. Today's episode was 0:04:39.400 --> 0:04:42.040 written by Patrick J. Kaiger and produced by Tyler Clang. 0:04:42.400 --> 0:04:44.760 Brain Stuff has merch now you can get phone cases, 0:04:44.800 --> 0:04:47.960 tote bags, and of course T shirts. Every purchase helps 0:04:48.040 --> 0:04:50.320 keep the show going and supports us directly. You can 0:04:50.360 --> 0:04:53.360 find all that stuff at t public dot com slash 0:04:53.480 --> 0:04:55.640 brain Stuff. For more on this and lots of other 0:04:55.680 --> 0:04:58.800 forward thinking topics, visit our home planet, how Stuff Works 0:04:58.839 --> 0:05:10.599 dot com.