Shredded plastic waste will be mixed with aggregate and used to repair the damaged parts of the 16-km Edapally-Aroor NH Bypass, from early 2020.
This comes close on the heels of the National Highways Authority of India (NHAI) gearing up to use 8,000 kg of shredded plastic waste to pave at least 4 km of highway corridors being built in Thiruvananthapuram and Palakkad.
Stakeholders in charge of the upkeep of the Edappally-Aroor Bypass said that the innovative method to construct roads that could better withstand Kerala’s rainy weather, would also be used to repave the entire stretch in 2022. “The Union Ministry of Road Transport and Highways (MoRTH) recently issued a circular to collect shredded plastic and use it for road works. Following this, NHAI officials were deputed to collect the materials locally. This would ensure proper reuse of plastic waste,” they said.
The NHAI has entered into a pact with Clean Kerala Mission to procure shredded plastic of uniform quality and size from its shredding units, at the rate of ₹21 a kg. If found successful, the mixing of the shredded materials with aggregate will be included in the detailed project report (DPR) of forthcoming highway projects in Kerala. There will not be any increase in the project cost, since there will be a marginal fall in use of bitumen, it is learnt. This will in turn pave the way for mechanisation of the process, following which the shredded waste can be used in much higher volumes. This reuse of plastic waste will hopefully lessen dumping of plastic on public spaces alongside highways and other roads.
Elaborating on the methodology that will be adopted for the process, an NHAI official said that the plastic would be mixed with aggregate and heated. “This will result in it forming a thin coating over the aggregate used for road works, lessening water retention of the aggregate. This will ensure roads that can better withstand rainy weather. Once the plastic melts and mixes with the aggregate, bitumen will be added and the compound used for paving roads.”
The main challenge is proper segregation of plastic waste so that the material has uniform properties. The NHAI officials have been directed to carry out impurity test to ensure that foreign particles constitute less than 1% of the shredded waste. Plastic is yet another petroleum product, just like bitumen and hence, will have similar binding effect on aggregate. Up to 2,000 kg of shredded plastic can be used to resurface 1 km of road.
