But it may help the environment instead if recycled as coated aggregate and mixed with hot bitumen for use in road construction work.
Experts say it is possible to recycle plastic, citing the examples of Chennai and Mumbai in India.
Prof Dr Rajagopalan Vasudevan, an Indian scientist who teaches at Thiagarajar College of Engineering in Tamil Nadu, has been working mainly on waste management. He has developed a method to reuse plastic waste to construct better and durable roads.
In an interview with the Guardian, Prof Vasudevan said: “Shredders, a gas cylinder, mixer machine, a wok and a pile of plastic garbage are my raw materials to make a plastic road.”
Pointing to a small pile of bags, plastic cups and foam packaging, he said: “These materials are the dregs of the plastic world, worthless even to rag pickers who cannot recycle them.”
Vasudevan melts shredded plastic over low heat to avoid emissions. “Polystyrene is toxic when burned but, when softened, it makes an excellent pothole filler.”
Bangladeshi environment researchers also support the method. Architect Iqbal Habib says plastic is a growing disaster destroying the fragile ecosystems.
“The plastic waste pollutes air, land, water and exposes toxic chemicals to the nature. So plastic is one of the main enemies of our environment. If the plastic can be recycled and used in road construction work, it will help our environment,” he told the Dhaka Tribune.
Prof Shamsul Haque of Buet said that the idea of plastic road was invented in the 70’s. At that time, the US faced troubles to manage their used tires which had stacked at the dump yards. “To overcome the problem, a Bangladeshi researcher, Prof Shahajada Mostak Hossain, took an initiative to recycle the tires and used those as raw materials for road construction,” he told the Dhaka Tribune.
Recently, India started using waste plastics as a raw material for road repair work. “But it is difficult to collect the plastic waste and prepare them for road work. So most of the countries use pellets instead of plastic waste for plastic roads.
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“If plastic waste is used for road work, it will help our environment but increase cost of construction,” Prof Shamsul added.
‘Not entirely without consequence’
However, the reintroduction of plastics into the environment is not entirely without consequence, Guardian reports. Old roads or poorly built ones are likely to shed plastic fragments into the soil and eventually waterways.
Dr Vasudevan specifies that only polypropylene (PP), polystyrene (PS) and polyethylene (PE) polymers should be used, and that PVC (polyvinyl chloride or flex) should not be allowed to contaminate the feedstock of plastic waste used in road laying.
Nityanand Jayaraman, a writer, researcher and activist based in Chennai, thinks plastic roads is not a solution. He says most of the chemicals used to convert plastics into daily-use products are highly toxic. “They can cause birth defects and cancer, and hormonal problems particularly for women,” Nityanand wrote in a website, adding that workers engaged in road-laying are particularly at risk from these emissions.