Anybody who’s ever broken a limb will appreciate the structural properties of a woven fabric impregnated with a fast-setting mineral matrix – a plaster cast, in other words. But how many people have seen the potential of this idea in the built environment?
Well, at least two people have, and they’ve built a business out of it. William Crawford and Peter Brewin conceived the idea of a disaster-relief shelter made from cement-impregnated fabric laid over an inflatable formwork for an engineering competition in 2004, while they were both students at Imperial College.
The cement-filled fabric could be delivered on a pallet and built on site with only basic tools and no special skills. As Charlotte Beatty, the company’s marketing manager, says, “it’s an instant building in a box – just add water”.
In August 2005 Crawford and Brewin set up a company, Concrete Canvas, and, with the help of some government funding, started to develop their idea. Two years later they set up a head office and factory on an industrial estate in Pontypridd, just north of Cardiff, and then in 2009 started commercial production.
“The main market at first was overseas disaster relief but they soon realised that the material had huge market potential in other applications,” says Beatty.
According to Beatty, Concrete Canvas has had to undergo a whole battery of tests before it could be approved for use on the trunk road network. “That’s the biggest challenge when trying to find new clients because the product is so unfamiliar,” she says.
Nevertheless, she says that “if you drive along any major road in the UK you’re likely to see Concrete Canvas channels”. The product is currently being installed in large volumes on the A14 upgrade project and the M1.
Concrete Canvas currently produces two products:
CC is the original product, a flexible concrete-impregnated fabric that hardens on hydration to form a thin, durable, waterproof concrete layer. Essentially, it’s concrete on a roll.
CC Hydro (or CCH) combines the basic concept with a highly impermeable, chemically resistant geomembrane liner; this product has been developed specifically for use in containment applications.
CC is simply unrolled, cut to length, positioned appropriately and hydrated; no specialist labour or equipment is required. CCH needs to be thermally welded to create an impermeable barrier and it has a built-in air channel to allow accurate on-site testing.
CC can be installed up to 10 times faster than conventional methods, says the company, and reaches 80% of its total strength within 24 hours.
According to Concrete Canvas, CC is recognised as an eco-friendly concrete alternative by the Environment Agency, which has specified the product for a number of projects in environmentally sensitive areas. The material has a low alkaline reserve and washout rate, eliminating the need to treat runoff, and a lower carbon footprint.
The product also has claims to occupational health & safety benefits since along with the reduction in plant requirements, labour and time spent on site, comes a reduced risk of accidents and damage to health.
In 2012 Concrete Canvas signed licensing agreement with a US manufacturer, the Millken Corporation, to set up the first overseas production plant, located in South Carolina. Today the company employs 45 people in six offices around the globe and exports to more than 50 companies.
Over the years Concrete Canvas has won numerous awards, including a Queen’s Award
for Innovation and Enterprise; in 2014 it was named the second-fastest growing manufacturer in the UK in the Sunday Times Fast Track 100.
Turnover grew 30% to £11m in 2018 and Beatty says the company is on track to grow another 30% this year. “We’ve already outgrown the Pontypridd factory and have recently completed the purchase of a new facility in Llantrisant,” she says. “It’s three times the size of our current factory.”
This article was first published in the March 2019 issue of The Construction Index magazine