If you can’t beat it, use it. Plastic waste, long considered one of the worst forms of environmental pollutants, may soon be one of the key ingredients for better roads in the city.
The Housing Infrastructure Development Corporation (Hidco) has given its nod to the use of plastic waste for laying a one-kilometre bituminous road stretch beside City Centre II in New Town as an experiment. The idea is to make the road surface tougher and enhance its life-span. The big question is whether a plastic-blended surface would make the surface tougher against its worst enemy: the rain.
Hidco authorities will soon hold a meeting with the Indian Plastic Federation and Indian Roads Congress (the apex body of road-construction engineers, functioning under the Centre) to discuss and firm up the modalities. “We will hold the meeting to chalk out the plan to use plastic waste for laying a kilometre of road,” said Hidco chairperson Debashis Sen. Hinging on the outcome of this experiment, Hidco authorities will decide whether this can be used for road repairs elsewhere.
Sources said shredded plastic waste can blend with bitumen at very high temperatures. The technology has been used in several states but its commercial viability is unproven. The Centre has been advocating it since 2015. In Kolkata, however, no such formal proposal has been received from any quarter, said a senior KMC official. “We had a proposal on the use of jute but that didn’t really take off,” said a Hidco official.
“IIT-Kgp’s civil engineering department had carried out a laboratory experiment. We, too, later conducted an experiment in the laboratory. The main issue is to properly blend the plastic waste with bitumen,” said road construction expert Sandipon Bose, the quality control head of Jalnidhi Bitumen Specialties Private Limited.
A road construction expert said: “A certain amount of crushed plastic waste will be first melted in high temperature, after which the melted plastic will be blended with the bitumen aggregator. This bituminous layer, blended with melted plastic waste, will be used in the top layer of the road.”
Experts said at present, polymer-modified bitumen, which has plastic granules mixed with it, is normally used in repairing small but important road stretches. “Polymer-modified bitumen is a costly material and thus it is not used extensively for repairing city roads. It, however, gives more strength and normally lasts at least 10 to 15 years more than the normal bitumen-layered roads,” said a road construction material expert.
“Using plastic waste can bring in two advantages. As plastic is water-resistant, having plastic mixed with bitumen will minimise the damage of roads from heavy rains. It will also serve the purpose of helping minimise plastic waste from polluting environment, as it will be recycled and mixed with bitumen,” said an official.
Source: Times of India