PLASTIC WASTE PELLETS COULD SOLVE ROAD CHALLENGE
Plastic waste pellets could solve two major problems in the world today, Toby McCartney believes.
One of these is the increased amount of plastic waste going in to landfill sites and littering streets and countrysides the world over.
"We went through about five-to-six hundred different designs of different polymers that we were mixing in before we found one that actually worked," he told CNN in an interview recently.
This final result is a mixture of blended waste plastics mixed in with ordinary asphalt to create a stronger, longer-lasting road. The pelletised granules of plastic waste replace 20% of the bitumen traditionally used to seal traditional roads.
"We are wanting to solve two world problems,” he told CNN recently. “On one side we call it the waste plastic epidemic, and on the other side the poor quality of roads that we have to drive on today."
According to reports, up to 20,000 single use bottles, or 70,000 plastic bottles can be used per ton of asphalt.
McCartney says his plastic solution is more cost effective and is a stronger binder, claiming that his roads are 60% stronger and that in lab tests, the roads are projected to last up to three times longer than traditional road surfaces.
MacRebur Plastic Roads, the company formed by McCartney is testing plastic pellets in roads in the UK, the Middle East, Canada, Australia and New Zealand.
McCartney reveals he was inspired while in India, when he saw how waste plastic was put into potholes and set alight in order to melt, effectively sealing the potholes.
Chemistry professor Rajagopalan Vaduevan from the Thiagaqrajar College of Engineering for developed the process, which involves shredded plastic on hot stones to form a thin primer coat. To this is added the bitumen, resulting in a strong bond.
This method has been utilised on approximately 100,000kms of road across India, and in 2015 the Indian Road Transport Ministry made it mandatory to construct roads using waste plastic in urban areas.
Indian environmentalist Almitra Patel told CNN: "Potentially plastic roads will make it possible for a city or state or the whole country for that matter to become zero waste to landfill if one follows the rules, but is a long way from happening.”
"If the plastic is permanently sandwiched between the stone and bitumen, there's no way it will ever see the environment," says Patel. "It will be ages before enough tar rubs off that you ever reach the plastic layer."
McCartney agrees, saying: "All our plastics are heated to around 180 degrees," adds McCartney. "They then fully homogenize in, so they mix in with the remaining bitumen in the road... So there is no micro-plastic present in any of our roads."