No potholes is the promise the developers of a plastic-based road surface being tested in Port Alfred. Horton Road, which runs past the main entrance of Settlers Park retirement complex, has had residents amazed as within a week, a construction team prepared a section of the dirt road, laid down a honeycomb-style interlocking base, filled the gaps with gravel and “iced” it with a layer of striated concrete.
The “honeycomb”, trademarked DiamondGrid, is marketed as being versatile in its applications, durable and ecologically friendly, “made from 100% recycled, UV-treated polypropylene”. Developed by the engineering faculty at the University of Queensland, Australia, the company’s website says it is widely used there, in the US and increasingly in Africa to stabilise muddy surfaces on farms, mines, and other places where heavy vehicles need to operate. It’s also used for aircraft runways in remote areas, walkways on golf courses, driveways, workshops floors, concrete pavements and car parks.
It’s marketed as a low-maintenance, low-impact solution for soil erosion, drainage and stability. Its life span, according to the company, is 30 or more years, compared to asphalt which lasts five to 10 years.
Advantages, say the manufacturers, include that it distributes the load more evenly across the surface of a road. That, and the fact that according to marketing it allows drainage (various distributors cite between 96% and 100% permeability) could make it less likely to form potholes and corrugations. And of course that, should it prove true, means less maintenance and fewer potential accidents.
Ndlambe Municipaity’s director of infrastructure Dr Noluthando Vithi responded to Talk of the Town’s questions about the Port Alfred project and directed this reporter to sources for the technical specs.
“The Horton Road application was a pilot project to test the product in our area,” Vithi said. “It’s the first road In Ndlambe where this product has been used.”
Residents in the area were happy – not necessarily about the product, but about the fact that part of the road was no longer a gravel surface, with its dust in dry conditions, and mud when it rains, Vithi said.
By what criteria would Ndlambe measure its success? How long would it take to decide if it’s successful and therefore replicable, Talk of the Town asked.
“As technology evolves, the municipality is free to test any innovation that could benefit the municipality and its residents – either by being briefed on proven research, or by practically testing a product as we are in Horton Road,” Vithi said.
“We will have an idea within about six months if it can bear the weight of the traffic and we will assess after a year if we can fully utilise the materials/product in other roads.
“We are assessing various elements of the product, including cost efficiency, construction effectiveness, durability and quality. We will also want to observe how the road responds to our weather conditions.”
How it’s made
First the road surface is prepared, by levelling and compacting it. Then the interlocking grids are placed in position. The interlocking grids used in Horton Road are 4cm high, and each interlocking block covers an area of 5.6cm x 9cm. Last. The empty grids are filled with gravel. In the case of Horton Road, a final layer of concrete was laid over the top of the test section.
YOUR OPINION
What do you think of the new “plastic” road? Email us at eidtorial@talkofthetown.co.za with ‘New road’ in the subject field. We’d love to hear from you!
