The Hindu 03.05.2013
A technology that makes the most of the plastic waste
The technology is used for laying “all-weather roads”
From October 4, 2002, when the first ‘plastic road’ was laid on Lenin Street, Kovilpatti in Tuticorin district, the technology of using waste plastic with stone for laying roads has come a long way.
Developed by the Department of Chemistry of Thiagarajar College of Engineering, Madurai, in 2001 and patented in 2002, the technology has been literally going places. It is now used in several other States, including Kerala, West Bengal and Himachal Pradesh, to lay “all-weather” roads.
It has also come as an answer to municipal solid waste management. Plastic is common man’s friend and its disposal is a human problem, says R. Vasudevan, who led the research into use of waste plastic for road laying.
According to him, used plastic comprises 2.8 per cent of municipal solid waste in Chennai, compared to 1.46 per cent of Delhi, 1.54 per cent of Kolkata and 0.9 per cent of Bangalore. Disposal of waste plastic either by burning or land filling is hazardous to the environment. The plastic road process involves shredding of waste plastic to small pieces (1.6 to 2.5 mm) and mixing with aggregate at a temperature of 170 degree C. Molten plastic waste laminates the stone in 30 seconds and plastic coated aggregate is added to bitumen for laying roads. The strength of the road gets doubled when plastic is used, says Dr. Vasudevan.
It can withstand heavy load and traffic and is not affected by water stagnation. Its minimum life is seven years, with zero maintenance. Performance studies carried out on plastic roads in Tamil Nadu, under Central Road Research Institute specifications, have shown “good results.” It is an in situ process and can be easily adopted, without use of additional machinery. There is no investment but only saving. Waste plastic found along road flanks in any area is enough for value addition, he says.
