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Posted at: Jan 8, 2017, 12:41 AM; last updated: Jan 8, 2017, 2:21 AM (IST)

Path-breaking plastic: One for the road

Bhanu P Lohumi in Shimla
What do you expect from a fifth standard boy struggling to cross a river to reach his school? Look back years later and count the time lost? No. Rakesh Kapoor (pic on right) thought of something else. He dreamed of a road skirting the river, and took his dream to his Master's degree in Himalayan Geology Jammu, and then to Ph.D in environmental geology, Chandigarh. 

"My father was posted in the horticulture department in the remote Bathara area between Jeori and Sarahan in the Rampur subdivision (Shimla district). While studying in Government Primary School Bathara, I had to cross the Sutlej through a jhoola bridge. Each time I crossed over, I wished if there were a road around!" recalls Dr Kapoor (58), special secretary (public grievances, Himachal Pradesh). 

"During my first posting as the block development officer in Gohar in Mandi in year 2000, I came across a science magazine in which a German author had written about using plastic in road construction," says Dr Kapoor. His next move: collect all sorts of domestic plastic waste -- polythene packaging, carry bags and milk pouches and mix it with bitumen. "We had to do something urgently because roads and small passageways get damaged in bad weather," he said. One passage was paved, then another. 

Today, this technique has emerged as a major contributor to "sustainable plastic waste management" in urban areas.

The project that he started has received National Award 2009-10 (PM award for best practices). Since 2014, the PMO has decided to replicate the project across the country with Kapoor being a key man in the implementation.

Plastic waste, he says, has emerged a major challenge in the municipal solid waste management. To steer clear of non bio-degradable plastics, almost all states have banned plastic and polythene of certain measurement. "Each person on an average uses 450-650 gm of plastic each day, which is over 15% of the municipal waste," he says.

From 'good environment' to 'good roads,' Dr Kapoor has also shown that the plastic use is good economics too. "Bu using plastic mixture, we can save Rs 35,000 to Rs 45,000 per km. One ton of plastic is used in a kilometer replacing 10% of bitumen," he says. The reduced bitumen quantity makes roads 30 per cent more durable. This was proved by CRI/NBRI Roorkee, IIT Delhi, Public Works Department, Himachal Pradesh and HP State Science and Technology Council, says Dr Kapoor.

R. Vasudevan, former dean, Thiagarajar College of Engineering, Tamil Nadu, which has patented the technology, claimed that the plastic mix had been effective in preventing wear-and-tear due to better binding properties, thereby increasing road longevity.

Former Engineering in chief HP PWD Naresh Sharma says three studies confirmed Kapoor's findings. "Since bitumen and plastic are both petro products with similar chemical properties, the mixture is homogeneous and provides a more durable surface," he said.

“I discovered something hidden in a scrap heap of books. And I made use of the waste, which otherwise, was unmanageable,” says Dr Kapoor. His village, meanwhile, is better linked, though there is no bridge to reach across the Sutlej. 

Grassroots benefits

  • The use of plastic in roads has also become a source of earning for rag pickers: Rs 12 per kg per day. This can go up to Rs 14 per kg for 5-10 kg and Rs 16 per kg for quantity exceeding 10 kg of plastic. 
  • The PWD would bill Rs 2 extra: Re 1 as handling charges and another rupee to be utilized for the welfare of rag pickers and waste workers by providing them boots, masks, gloves, free medicines and an insurance cover of Rs 2 lakh in case of any eventuality.
How it works

  • Plastic waste is cut into a size between 2.36 mm and 4.75mm using shredding machine.Bitumen is heated to 160 deg C to prevent weak bonding. At the mixing chamber the shredded plastic waste is added to the hot aggregate. It gets coated uniformly within 30 seconds. 
  • Hot bitumen is then added over the plastic-coated aggregate and the resulting mix is used for road construction. The road-laying temperature is between 110 degree C and 120 degree C.


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