Plastic Roads: A backgrounder

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.

 

Advantages

Longevity

• 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.

Low-Defects

• 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.

Low Cost

• 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.

 

Disadvantages

• 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.

 

Issues

Low adoption

• 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.

No Target

• 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.

 

Way Forward

• 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.