Two engineering students competing in a British Cement Association competition to find new uses for cement based their entry, an inflatable concrete shelter for refugee relief, on meditations about the compressive strength of an eggshell. “We came up with the two critical components of concrete canvas,” say Peter Brewin and Will Crawford, who met at the Royal College of Art, where both studied industrial engineering, “a cement-impregnated cloth and inflatable formwork.”
The structure comes in a pack containing cement-impregnated fabric bonded to the outer surface of an inflatable plastic liner. The sack is filled with water to hydrate the cement and, after 15 minutes, cut to form the ground sheet for the structure. A chemical pack is activated to produce a controlled volume of gas that inflates the structure. After the concrete cures, areas of the plastic skin left free of fabric are cut open for doors and ventilation.
Brewin and Crawford have started up Concrete Canvas, Pontypridd, Wales, to develop, manufacture and market the new structures, but both men sell to aid organizations preferentially and as cheaply as possible. “We’re most interested in the humanitarian applications,” says Brewin, such as providing safe, weatherproof temporary housing for some of the 33 million refugees and displaced persons worldwide. For more information, see the Concrete Canvas Web site at www.concretecanvas.co.uk.