Drawing courtesy of CPV Architects and Engineers Ltd.

CCIT supplies concrete evidence

Civil engineers give high marks to innovative building material

by Dennis Urquhart

Researchers in the Calgary Centre for Innovative Technology (CCIT) awarded a strong passing grade to an innovative construction material that promises new design possibilities for buildings, bridges and other structures.

A team of U of C civil engineers recently completed tests on a cement-based material called Ductal, a product developed by Lafarge North America Inc.

“ This is one of the biggest steps forward in structural engineering in 50 years,” says U of C civil engineering researcher Tom Brown. “This is very, very innovative material.”

Ductal is a cement-based composite which can be made with both metallic and organic fibres. It is stronger and more durable than concrete and doesn’t require steel reinforcing as concrete does.

“ This material will allow architects to create innovative structures,” adds Vic Perry, Lafarge’s vice-president and general manager of Ductal.

The first major construction project of its kind employing Ductal will be a canopy roof for the City of Calgary’s new Shawnessy LRT station, which will open next summer.

A prototype Ductal canopy shell was installed in the CCIT building last June and researchers began their clinical trials on Ductal in July. This contract research project was the first such test conducted in the CCIT’s new high bay lab.

Brown and colleague Nigel Shrive (left)– along with six graduate students and two undergraduate students – performed wind uplifting and snow loading simulations, as well as computer-modelled calculations on the five-metre-by-six-metre, two-centimetre-thick canopy.

“ It passed the tests with flying colours,” Shrive says.

U of C master’s student Blair Scholefield was part of the research team. He says the contract research project allowed him to put classroom theory into practise as well as earn cash to support his grad studies.

“ It was a great opportunity to learn how things work in industry and how people work together on these types of projects,” he says.

Civil engineering professor Lynne Cowe Falls is also impressed by Ductal’s test results. She adds that pigments can be mixed into the Ductal to “move concrete out of the boring greys” and allow for more vibrant new buildings and structures.

Testing new materials such as Ductal is nothing new for U of C researchers, says Shrive. The City of Calgary routinely enlists the U of C engineers to ensure various structures and materials are safe for the public or present the best option for taxpayer dollars.

For example, the U of C ran tests on various rubber pads that support LRT rails on their concrete base and advised the city on which ones performed the best. U of C experts have also tested bridges, support columns and roadway noise barriers.

“ Just look at the infrastructure budgets that governments have; we’re talking about billions of dollars,” Shrive says. “As well as ensuring public safety, these tests help save the city and taxpayers countless dollars in the long run.”