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.
Section : Environment & Ecology

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