Greener, stronger concrete

What if you could take one of the heaviest greenhouse gas producing processes in the industrial world and turn it on its head? So that carbon dioxide is actually taken out of the atmosphere and absorbed into a finished product, making it both greener and better?

That’s exactly what Halifax-based CarbonCure Technologies Inc. has done.

Concrete is all around us; a fundamental part of just about every construction project. Unfortunately, the production of Portland cement, the main ingredient in concrete, creates a huge amount of carbon dioxide—up to 0.8 tonnes of the gas for each tonne of cement. Making cement is responsible for about five per cent of the world’s human-made carbon dioxide. The cement industry is second only to power generation in terms of greenhouse gas emissions.

With today’s focus on greenhouse gas reduction and sustainability, the industry has been under serious pressure to do something about it.

While a Masters student at McGill University, Robert Niven studied the benefits of using carbon dioxide in concrete production. Niven’s academic interests led him directly to the development of the CarbonCure system, and the company he founded in 2007.

A chip off the old block

“In a way, it’s nothing really new,” says Jennifer Wagner, CarbonCure’s vice president of marketing. Carbon dioxide was used in concrete production as far back as the 1940s to control efflorescence—the white streaks visible on some concrete buildings and structures—and shrinkage. “The old technology was to fill a room with carbon dioxide, and put the product in there. The (concrete) would react with the gas, and create a protective coating.

“We use the same theory, but we’re forcing carbon dioxide to react earlier in the process, throughout the material.”

The reaction creates CaCO3, commonly known as limestone. The limestone gave concrete its protective coating; CarbonCure’s process creates limestone throughout the entire concrete block, strengthening the finished product.

Why does that matter?

Wagner points to two environmental benefits. First, the carbon dioxide sequestered in the concrete comes from a “final emitter” —a power plant, refinery or another CO2-spewing operation. That means greenhouse gases are diverted from the atmosphere and put to good use.

Second, stronger concrete has fewer defects and lasts longer, meaning there is less wastage. It also cures faster, reducing energy consumption and cost.

It can add up to as much as a 20 per cent reduction in carbon dioxide emissions. It’s no surprise CarbonCure is attracting plenty of interest.

Since 2007, Wagner says, CarbonCure has been “ramping up very quickly.” In January 2013, the company opened a new, larger laboratory space in Burnside Industrial Park, improving on its smaller previous space on Cunard Street in Halifax’s north end. The month before, it announced the creation of 24 new jobs.

CarbonCure has spent five years testing their technology, through partnerships with the Shaw Group in Nova Scotia, Basalite Concrete Products in California, and Ontario’s Atlas Block—all large suppliers to the construction industry.

Earlier this year, Atlas Block became an official licensee (ie, paying customer), permanently installing CarbonCure’s technology and using it across their line of products. Atlas Block/ CarbonCure concrete is earmarked for a number of major projects, including new sports centres for the 2015 PanAm Games.

Awards for the block

CarbonCure was named one of the 10 most promising Canadian cleantech startups by Corporate Knights in 2012. BuildingGreen. com picked the company’s carbon dioxideabsorbing concrete blocks as one of its 2013 top 10 building products.

Implementing the CarbonCure system is relatively easy, “simple and elegant,” says Wagner. The equipment can be bolted directly on to the existing production line— there is no need for huge investment in new buildings or massive machinery.

“We’ve been very well received,” she says. “Many of our customers have trouble positioning their products as green. We can help with that.

“Manufacturing benefits are important as well—helping to make stronger concrete.” Turning greenhouse gases into solid limestone. Creating stronger, greener, and cheaper concrete. What’s next?

Stay tuned, says Wagner.

“We’re building up our R&D capacity. We’ll always be pushing the envelope and creating better, greener products.”

Stephanie Porter
About Stephanie Porter

Stephanie Porter is a freelance writer and editor living in St. John’s. In 2003, she helped launch The Independent, a spirited weekly newspaper distributed across Newfoundland and Labrador, known for its investigative news and features. Stephanie was managing editor of the paper until its untimely demise in 2008. She has also worked as a reporter and writer for Downhome magazine, the Express (also now defunct), The Globe and Mail and The Toronto Star, picking up Atlantic Journalism Awards for her feature and news writing. Stephanie is delighted to be a regular contributor to Atlantic Business Magazine. Photo Credit: Paul Daly.

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