India is confronted with a huge waste problem. Plastic is one among them as it pollutes waterways, landscapes. Plastic bags are, thus, being extensively used for road surfacing as plastic and tar bond well together because both are petroleum products.
An initiative idea has paved a way to use plastics in Road construction.
Since plastic roads are a relatively new idea, construction processes may vary. Some of the most common plastics used in packaging are polyethylene terephthalate (PET or PETE), polyvinyl chloride (PVC), polypropylene (PP), and high and low-density polyethylene (HDPE and LDPE)
Plastic roads mainly use plastic carry-bags, disposable cups and bottles are collected from garbage dumps as an essential ingredient of the construction material.
When mixed with hot bitumen, plastics melt to form an oily coat over the aggregate, and the mixture is laid on the road surface like a normal tar road.
The plastic tar roads have not developed any potholes, rutting, ravelling or edge flaw, even though these roads are more than four years of age observed an early performance report by India’s Central Pollution Control Board.
Dr R Vasudevan, a chemistry professor came up with the idea of plastic road
Dr R Vasudevan, a chemistry professor and dean at the Thiagarajar College of Engineering in Madurai, came up with the idea through trial and error, sprinkling shredded plastic waste over hot gravel and coating the stones in a thin film of plastic.
He then added the plastic-coated stones to molten tar or asphalt. Plastic and tar bond well together because both are petroleum products. The process was patented in 2006.
Today, there are more than 21,000 miles of plastic road in India, and roughly half are in the southern state of Tamil Nadu. Most are rural roads, but a small number have also been built in cities such as Chennai and Mumbai.
The first road to construct with plastics is Nungambakkam in Chennai.
A modified version of the road which adds road scrap to plastic-coated gravel was tested out in March this year on a highway connecting Chennai with Villupuram. It was the first time plastic road technology was used for a national road. It is expected to reduce construction costs by 50%.
They require a hefty dose of government intervention to succeed. Tamil Nadu was the first state in India to develop a cottage industry around shredded plastic actively.
Most plastic shredders are women who buy subsidized shredding machines and sell their finished product for a small profit. Job creation for waste pickers and small entrepreneurs is an added benefit of the roads – a point not lost on India’s prime minister.