India is embarking on an ambitious program to build a three million kilometres of road network and a Canadian technology which extends paving lifecycle is getting a close look as a key component.
It began five years ago with a small stretch of road in the rural Indian village of Thondebhavi when a pilot project developed by the Canada-India Research Centre of Excellence IC-Impacts at the University of British Columbia (UBC) campus leveraged the work of UBC civil engineering professor Nemy Banthia.
That small stretch of road has weathered five monsoons since it was constructed and is as smooth today as the day it was laid, says Banthia.
“The road built beside it with traditional technology washed out within about two years,” he says.
Intrigued, the Indian authorities took the technology to their testing labs and hammered on it before emerging with a thumbs-up.
Now two 10 km stretches have been commissioned in Madhya Pradesh state and Karnataka state and will be finished by this summer.
The concept uses short 20 mm strands of co-extruded polyolefin core about 0.3 mm in diameter with a special coating. Think electrical wire where the copper wire is wrapped in plastic. The plastic covering in this case is a nano-coating which activates with moisture to seal-heal the concrete it is embedded into.
These strands are added into concrete so that they form a random 3D mesh within the mix.
This imparts strength in more ways than one, Banthia says, in that any cracks have no path to run along because the mesh strands impedes their progress. At the same time any moisture that does find its way into the concrete immediately activates the nano-coating which form calcium silicate hydrate which acts to self-heal.
The net result is there’s a third less concrete used and the paving depth is similarly a third of traditional roads. However, this is offset by a 33 per cent higher cost of adding the fibre strands.
The big offset though is a three times longer lifecycle, says Banthia.
“We’ve also tweaked and improved it over the last five years so that we’ve reduced the carbon footprint by a third as well,” he says noting the mix is 60 per cent ash from local thermal power plants and they are incorporating fibres from scrap tires, helping divert at least some of the four billion tires which aren’t recycled every year.
It has also stood up to five Indian monsoon seasons which have foiled other roads. “In India we say it’s raining tigers and cougars in monsoons not cats and dogs,” he laughs.
A Canadian pilot is also underway to test cold weather performance with a 26-by-18-metre lot parking lot at Chawathil First Nation near Hope, B.C. being built last year using a tweaked formula for winter hardiness.
Given the construction sector’s resistance to adopting new and innovative technologies, Banthia doesn’t expect it to take off overnight, not even in Canada where it was created.
“It takes time,” he says, and is resigned to the long road of explaining how it works and lobbying for more demonstration projects across Canada and around the world to build trust and win support.
“Even if you had the best sliced bread in the world, there are people who would think a loaf would be better,” he says. “But the thing about this is it can be used in any kind of concrete mix for any kind of concrete application, from precast to structures. But it is an uphill battle.”
The key for Canada is to license the technology and export it, he says. That way the local jurisdictions get the benefit of manufacturing the components and technology under license which in turn creates on-going jobs and further integrates the product and process into the local economies.
Also, he says, licensing moves Canada away from chiefly being an exporter of resources and products and into a different realm, meaning more diversity of the economy.
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