The disposal of used plastic is a major environmental issue across the world. From limiting the use of plastic to outright bans, governments have experimented with various methods to work around the issue of disposing plastic. However, now, the Central Government has called on all state governments to utilise plastic waste for a major infrastructure purpose — the construction of new national highways.

 

The Ministry of Road Transport and Highways recently issued a directive to all state governments and union territories to use a mix of bitumen and plastic waste on at least a 10KM stretch of highway as a pilot project.

 

The use of plastics for road construction is not new. Polymer-modified asphalt has been used in Europe and North America for over 40 years. The use of plastic offers significant advantages: the roads can better withstand extreme weather (snow and high temperatures), are more resistant to water stagnation and the formation of potholes and have very low maintenance costs. However, price has been a major limiting factor — even in the U.S., the use of polymer-modified asphalt raises the cost of road-laying projects by around 30%.

 

Enter the renowned Indian trick of jugaad! Dr R Vasudevan, a chemistry professor at the Thiagarajar College of Engineering in Madurai, had been researching on the use of low-grade plastic for road work. He found that using shredded plastic waste from around 1 million plastic bags for a kilometre of road would save around 1 tonne of asphalt and cost only 8% as much as a conventional road. Plastic and asphalt bond well as both are derived from petroleum. Vasudevan patented his method in 2006.

 

In March 2016, plastic waste was used to build a section of the Chennai-to-Villupuram highway; this was the first instance of using the material on a highway. As of mid-2016, plastic had been used to lay about 21,000 miles of roads in India; of this, roughly half were in Tamil Nadu. However, these earlier implementations were mostly targeted at rural roads. The use of plastic waste for highways will also generate employment opportunities for ragpickers while reducing pollution.