Building roads using plastic waste not only makes them more durable against wear and tear, it could also provide a long-term solution to our waste management woes.
The benefits of incorporating plastic waste into roads go beyond waste management. Not only does it keep tonnes of plastic from the landfill (or worse, the ocean), it also helps reduce carbon emissions, improves road quality and even provides cost savings.
In the fight to combat plastic pollution, and manage its increasingly unmanageable volume, governments around the world have started implementing plastic bans to help curb the production of single-use plastic. While widely considered a positive move, for one professor in India, this was a worrying development that could be detrimental for low-income families in the country.
This was the concern that ultimately led Rajagopalan Vasuevan, a chemistry professor at the Thiagarajar College of Engineering in India, to pioneer the use of plastics in road construction. For him, plastics weren’t the problem. The problem was what we were—and weren’t—doing with it. Plastic was being disposed of, often improperly and to significant environmental harm, when instead it should be utilised beyond its initial use.
His efforts to figure out what to do with plastic waste led him to discover the effectivity of molten plastic as a binder. By combining it with stone and bitumen, both common roadbuilding materials, Vasuevan was able to form a strong and flexible aggregate that improved a road’s load bearing capacity and prevented potholes, therefore slowing down deterioration. It also reduced the amount of bitumen needed for construction, thus saving around £480 per kilometre of road.
India, and other parts of the world, have taken notice of the manifold benefits of this technology not just for the environment, but also for infrastructure. Starting from just one 18-metre road in his school campus in 2002, plastic waste is now part of about 2,500 km of roads in India, and growing, buoyed by a 2015 government mandate requiring the use of plastic waste for roads around cities with a population of more than 500,000.
Around the world, other plastic-made roads are also popping up. MacRebur, a company based in Scotland, has applied some of Vasuevan’s technique, together with their own patented method, to build plastic roads within the country, and as far as South Africa and Australia. In the Netherlands, PlasticRoad was able to build a bicycle path without using any bitumen. A few other countries, such as Ghana, Vietnam, Mexico, the Philippines and the United States, have also recently built roads using plastic waste.
By providing a second life to plastics, these plastic roads are taking plastic away from the waste stream. That means keeping tonnes of trash out of landfills and out of the ocean, reducing carbon dioxide emissions from incineration, and enabling the reclamation of hard-to-recycle plastics.
Because of the technology’s relatively recent development, there is still much of it that needs to be tested. More research has to be done regarding the environmental impact of melting plastics, as well as the possibility of microplastics leaking into the soil. It is also important to consider the possible inconsistencies in quality of the roads due to the differing characteristics of the diverse components in plastic waste.
Nevertheless, the use of plastic in roads is a step in the right direction. A durable material such as plastic is not meant to be used just once and thrown away. We need to take advantage of its sturdy properties to create safe and lasting infrastructure that can withstand decades of wear and tear. There is now a worldwide effort to repurpose plastic waste into new products, such as clothing and building materials. As people discover more ways to reuse plastic, we can start to think of plastic not as waste to be disposed of, but a valuable resource to build on.
Main Source:
Lee, Chermaine. “Could Plastic Roads Make for a Smoother Ride?”, BBC Future, BBC, https://www.bbc.com/future/article/20210302-could-plastic-roads-make-for-a-smoother-ride.
Other Related Sources:
Fourtainé, Susan. “Smart Cities: From Plastic Pollution to Plastic Roads”, Interesting Engineering, https://interestingengineering.com/smart-cities-from-plastic-pollution-to-plastic-roads.
McCarthy, Joe. “Recycled Plastic Is Being Used To Repave Roads Around The World”, Global Citizen, https://www.globalcitizen.org/en/content/plastic-road-california-environment/.
Parson, Ann. “How Paving with Plastic Could Make a Dent in the Global Waste Problem”, Yale E360, https://e360.yale.edu/features/how-paving-with-plastic-could-make-a-dent-in-the-global-waste-problem.
Rueckert, Phineas. “India has Laid 620 Miles of Road Made With Recycled Plastic”, Global Citizen, https://www.globalcitizen.org/en/content/india-roads-recycled-plastic/
Smith, Kristina. “From Bangalore to Dumfries, Plastic Waste Technology is Reinforcing our Roads”, World Highways, https://www.worldhighways.com/wh6/feature/bangalore-dumfries-plastic-waste-technology-reinforcing-our-roads
Thiagarajan, Kamala. “The Man who Paves India’s Roads with Old Plastic”, The Guardian, https://www.theguardian.com/world/2018/jul/09/the-man-who-paves-indias-roads-with-old-plastic