In a city with over 7,000 kilometres of road length and generating large amounts of plastic waste, are we missing a golden opportunity to recycle plastic waste by using them to lay roads?
R. Vasudevan, Dean, Thiagarajar College of Engineering, Madurai, who holds the patent for plastic roads, says the technology for plastic roads is now proven and could be used in a city that is prone to water stagnation and frequent road cuts. “It reduces maintenance costs and restoring road cuts costs much less. It is also a scientific way to tackle plastic waste,” said Mr. Vasudevan.
The Chennai Corporation made a positive beginning in 2012 by proposing to pave 1,500 km of roads using plastic waste and 40 plastic shredder machines were also purchased for this. However, due to some reasons, the project has not taken off. Jambulingam Street in Nungambakkam that was one of the first roads to be laid using this technology in the city is unfortunately nothing to showcase.
Mr. Vasudevan, ruing the backtracking of the promise to pave more than 1,500 km of roads using plastic waste by the Chennai Corporation, believes some hidden agenda could be behind the contractors’ unwillingness to use this indigenous technology.
A senior official of the Chennai Corporation pointed out that the ‘shortage’ of plastic waste of uniform 40 micron thickness was the main reason behind the project not taking off. Also road contractors, who are covered by the liability clause, are reluctant to use plastic waste for fear of road not passing the quality test in certain cases.
But all has not been lost as the civic body has proposed to make it conditional for contractors to use plastic waste on bus route roads that would be laid shortly, he added.
Stronger roads with increased Marshall Stability Value *
Better resistance to rain water and water stagnation
Increased binding means better bonding of blue metal and bitumen
Reduction in the percentage of pores and hence less rutting
Reduction in the percentage of pores and hence less rutting
* a benchmark for identifying the strength of the road
The Process
1 The plastic waste is shredded into small pieces using shredding machines
2 The shredded waste is then added to the blue metal, which has already been heated to around 170 degree Celsius.
3 The plastic is mixed with the heated blue metal, thereby melting it with the stone
4 Then, bitumen is added and mixed with the plastic-coated stone, which would be used for road construction.
