Plastic Roads: A backgrounder
- Plastic roads are in vogue lately with Centre for Studies on Solid Waste Management, working on use of shredded plastic in asphalt in road construction.
- The process of making plastic roads was patented in 2006.
What are Plastic roads?
- Plastic roads are tar roads constructed out of asphalt mixed with flexible polymer glue made from shredded waste plastic.
- The shredded plastics are made of plastic bags, cups and foam packaging which contain Polystyrene.
- The shredded plastic is then softened over low heat to avoid emissions and then sprinkled over hot gravel, coating the stones with a thin film of plastic.
- This plastic-coated stones are then added to asphalt (molten tar) which is used in constructing roads.
- While asphalt roads last for three years, plastic road has longevity of seven years.
- The polymer-glue made of plastic bond well with bitumen in asphalt, thereby enhancing the ability of the road to carry weight and hence its longevity.
- Further according to CPCB plastic roads do not develop defects such as potholes, rutting, ravelling or edge flaw, even after four years.
- Further plastic ensures waterproofing thus reducing wear and tear.
- Every Kilometer of plastic road constructed requires 1 tonne of plastic waste and 9 tonnes of bitumen.
- Every tonne of bitumen saved will cost approximate ₹50,000 less.
Gateway to plastic waste
- According to estimates, 15,000 tonnes of plastic waste is generated in India every day and 9 million tonnes every year.
- Further only 14 % of plastic packaging is collected for recycling.
- According to Indian Roads Congress, if all the roads built in the country between 2013 and 2016 had used 6%-8% plastic waste, around 330,605 tonnes of plastic scrap could be curtailed.
- Building plastic roads means reintroduction of plastics into the environment.
- Photodegradation of plastics may produce microplastics which may seep into the soil and ground water.
- Microplastics act like magnets for pollutants like polychlorinated biphenyls (PCBs).
- Microplastics may persist, bioaccumulate, and can severely affect the biodiversity of the soil.
- Further if PVC is used in shredded plastics it may produce dioxins which are extremely harmful.
Plastic Roads in India
- Tamil Nadu is the first state to have adopted the plastic road technology with nearly half the roads are made of plastic.
- Over 16,000 km of plastic roads were laid in Tamil Nadu till 2014.
- Further plastic roads are constructed in Himachal Pradesh, Madhya Pradesh, Kerala, Meghalaya and in neighbouring Bhutan.
- Further the government is encouraging the use of waste plastic in National Highways within a 50 km periphery of urban areas that have a population of 5 lakh or more.
- While some states have like Tamil Nadu have adopted the technology, some states are yet to take off.
- Delhi for instance has not gone beyond pilot demonstrations.
- Though there is recognition from government about the efficacy of the technology in building National Highways, no target has been set for it during 2017-18.
Lack of enforcement
- In 2015, the Union government issued guidelines on plastic use with hot mixes for bitumen roads around urban areas
- However the civic bodies, road contractors and the Public Works Department haven’t followed the guidelines due to vested interests.
Lack of availability of shredded plastic
- Further lack of availability of shredded plastic due to lack of enforcement of rules by municipal authorities.
- Adoption of plastic technology should be encouraged in National Highway construction.
- An incentive scheme for segregation, cleaning, and cutting of plastic is necessary to make it available as a raw material.
- Instead of a blanket ban on plastic, what we need is a ‘garbage culture’ and a proper collection system in local bodies.