From trash to treasure: The untold story of India’s plastic roads 

You may have seen bottles, bags, toys, and many other things made of plastic. But did you know that roads can be made of plastic too? That's right! These roads have become a great way to recycle plastic. Dr. Rajagopalan Vasudevan, an Indian scientist, introduced the idea of using waste plastic in road construction. Initially, Chennai was one of the few cities in the world to extensively use this technology. The municipality ordered the construction of 1000 kilometres of plastic roads in 2004. However, the effective use of plastic in road construction in India only began later in 2015 when the Union Government instructed the use of waste plastic with hot mixes. This combination was to be used for bitumen (a thick and black adhesive liquid) roads surrounding the metro areas. Then, Nitin Gadkari, the Minister of Road Transport and Highways, initiated highway construction using waste plastic. As of July 2021, 703 kilometres of national highways have been built using this technology. Do you want to know more about innovative plastic roads? Let us then unravel this story! 

Dr Rajagopalan Vasudevan: The Plastic Man of India  
Dr Vasudevan is famously known as the Plastic Man of India and rightly so. In 2018, he was also honoured with the Padma Shri, India's fourth-highest civilian honour. A professor at Thiagarajar College of Engineering in Madurai, Tamil Nadu, Dr. Vasudevan’s area of research includes garbage management. Dr. Vasudevan created a method for recycling plastic waste to build more robust, resilient, and affordable streets. His novel approach is now frequently employed in rural India.  

Dr. Vasudevan and his team at the Centre for Studies on Solid Waste Management (CSSWM) have researched the viability of plastics in road construction since 2001. In 2002, they conducted an experiment where they mixed used plastic with heated bitumen and poured this mixture over stone. They used this mixture to build a road inside the college premises. This technology was so successful that the college was awarded a patent in 2006.  

What type of plastic can be used? 
You must be wondering, what type of plastic goes in the constriction of plastic roads. Many waste items can be used for road construction. Some are: Plastic carry bags, mugs, plastic cups, and plastic packaging for chips, cookies, and chocolates. 

The Ministry of Rural Development also released a circular on using plastic waste in constructing rural roads which can be built using carry bags, cups of a maximum of 60 microns (thickness), hard foams and soft foams of any thickness, laminated plastic, and aluminium-coated packing materials up to 60 microns in thickness. However, Poly Vinyl Chloride (PVC) or flux sheets are not allowed. 

How are plastic roads created?  
Using plastics to make roads is complicated. But it is an interesting process indeed. The first step in the procedure of making plastic roads is shredding. The plastic materials received are crushed into small bits in this step. All the dust particles are also removed here. In the second step, all the crushed pieces are mixed with hot gravel. This mixture is warmed to a temperature of 160°C so that all the plastic melts. It is then poured onto the hot asphalt roads. This is how the roads are paved.  

The procedure is simple as it does not need extra equipment or industrial participation. Moreover, a lower percentage of bitumen usage results in less use of its resources. Most importantly, plastic garbage is used safely. It is environmentally beneficial and does not release any hazardous gases like dioxin. 

Are the plastic roads safe? 
The Central Pollution Control Board (CPCB) evaluated the performance of plastic roads and found that the streets did not exhibit any common flaws even after four years. There were no potholes, ravelling, rut depth, rodding, or edge fault.  

Highways made of plastic increase environmental sustainability. They are shown to be more reliable and economical. Because both plastic and bitumen are made of petroleum, these items adhere to one another well. That's why they lengthen the lifespan of the roads and increase their capacity to support weight. The plastic streets exhibit increased resistance to rain damage too. Plastic roads are a prime example of how humans can make treasure from trash! They are also a positive step towards repurposing plastic which is harmful to the environment.