South Africa managed to find a single solution to two problems it’s currently facing. The country is now recycling plastic milk bottles to make new roads, hoping to solve its waste problems while improving the quality of the roads.
Shisalanga Construction became in August the first company in South Africa to lay a section of road that’s partly plastic, in KwaZulu-Natal (KZN) province on the east coast. It has now repaved more than 400 meters of the road in Cliffdale, on the outskirts of Durban, using asphalt made with the equivalent of almost 40,000 bottles.
In order to make the roads, the company uses a thick plastic typically used for milk bottles known as high-density polyethylene (HDPE). They replace six percent of the asphalt’s bitumen binder, so every ton of asphalt contains roughly 118 to 128 bottles.
The method releases fewer toxic emissions than during traditional processes and its compound is more durable and water-resistant, withstanding temperatures as high as 70 degrees Celsius (158F) and as low as 22 below zero (-7.6F).
While the cost is similar to other methods, the company believes there will be a financial saving as its roads are expected to last longer than the national average of 20 years. “The results are spectacular,” said general manager Deane Koekemoer. “The performance is phenomenal.”
About 70% of the plastic in South Africa is sourced from landfill. The plastic will only be taken from landfill if there is somewhere for it to go — such as into roads. Shisalanga says that by turning bottles into roads it is creating a new market for waste plastic, allowing its recycling plant partner to take more out of the nation’s dumps.
Shisalanga has applied to the South Africa National Roads Agency (SANRAL) to lay 200 tons of plastic tarmac on the country’s main N3 highway between Durban and Johannesburg and is awaiting approval for the project. If it meets the agency’s requirements, the technology could be rolled out across the nation.
India began laying plastic roads 17 years ago, and the concept has been tested in locations across Europe, North America, and Australia. But there are concerns over potential carcinogenic gases created during production and the release of microplastics (tiny particles of plastic) as the roads wear away.
Shisalanga has spent five years researching the technology. Its technical manager Wynand Nortje said its method of melting the plastic into the bitumen modifier minimizes the risk of microplastics. “The performance of our plastic mix is better than traditional modifiers, the fatigue seems improved and resistance to water deformation is as good or better,” he adds.
Roads are one of many creative solutions to reusing plastic waste. Companies around the world are turning it into bricks, fuel, and clothing. Some other international companies have even found ways to repurpose so-called “non-recyclable” plastic into roads.
