South African roads have always had a reputation for their poor quality and loathsome potholes. Thankfully, Shisalanga Construction have come up with a way of improving the quality of roads whilst reducing waste at the same time.
In August of this year, Shisalanga Construction became the first company in South Africa to pave a section of road in KwaZulu-Natal that is partly made of recycled plastic. Shiaslanga achieved this by sourcing a local recycling plant to turn high-density polyethylene (plastic milk bottles) into tiny pellets by heating them to 190°C. The tiny pellets were then dissolved and mixed with additives to replace 6% of the asphalts bitumen binder (the chemical that increases stiffness in road construction) meaning every ton of asphalt contains about 128 recycled milk bottles.
According to Shisalanga, fewer toxic emissions are released into the atmosphere through this method of road construction compared to the traditional method. Along with being better for the environment, this new compound is far more durable than conventional asphalt as it has the ability to withstand temperatures as high as 70°C and as low as -22°C below zero.
The price of laying down plastic tarmac roads is similar to existing methods, but the company believes there will be financial savings in the long run, as the roads are expected to last 20 years.
“The results are spectacular,” says general manager Deane Koekemoer. “The performance is phenomenal.” while speaking to the Mail&Guardian
While there are concerns over the potential for the release of microplastics into the environment as the road wears away over the years, technical manager Wynand Nortji is not too worried. He said: “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.”
Shisalanga have made a request to the South African National Road Agency to lay down 200 tons of plastic tarmac compound along the main N3 highway between Johannesburg and Durban but has yet to receive approval for the project.
Image: Shisalanga Construction