A staple of industrial construction worldwide, concrete block is long-lasting, inexpensive and easy to install. But its key ingredient is cement, a grey powder whose own production process makes it a major emitter of carbon dioxide gases that contribute significantly to global warming.
A Halifax startup is among those looking to reduce concrete's carbon footprint.
Founded in 2007, CarbonCure Technologies Inc., has developed a patented technology to produce environmentally-friendly concrete blocks that look, perform and are priced the same as conventional block. This year, the company has licensed its technology to 30 concrete factories in Canada and the United States. With plans this year to sell green paving stones, CarbonCure is currently working to adapt its technology for precast and ready-mix concrete.
Analysts say the global appetite for green concrete and other environmentally-sensitive building materials is being fed by consumer demand, government regulation and investor interest. A 2013 study by Navigant Research estimated the global market for green construction materials (including concrete) will grow to more than $254-billion (U.S.) by 2020 from $116-billion last year.
"Green concrete markets are emerging and will be a function of their contribution to meeting both regulation and demand from LEED property development and retrofits," says Céline Bak, chief executive officer of Analytica Advisors, publisher of the 2014 Canadian Clean Technology Industry Report, in an e-mail. "Major players are investing in the business models to grow these markets to scale."
Last January, a report by Global Industry Analysts forecast that, fueled by demand in Asia-Pacific countries, U.S. sales of green concrete (which uses recycled waste products in its production) are expected to surge to $28.7-billion from $6.1-billion in 2010.
"Consumers and customers are really getting on the bandwagon and pulling [green building] product through the channel," says Tony Van Bommell, senior managing partner of BDC Venture Capital, an arm of the Business Development Bank that last year led a financing round to raise $3.5-million for CarbonCure's expansion plans.
Though the science is complicated, the idea behind CarbonCure is relatively simple – turn waste carbon dioxide, previously a polluting liability, into a valuable input in the production of concrete.
"Carbon dioxide was the biggest environmental liability of the concrete sector and we are now using it as their asset," says Robert Niven, founder and chief executive officer of CarbonCure. "We are totally flipping the paradigm here and doing it at an exceptionally low cost."
The technology enables concrete manufacturers to permanently absorb waste carbon dioxide in the production of block through a chemical process that transforms the greenhouse gas into solid limestone, strengthening the concrete while reducing the cement content. A concrete manufacturer's operation can be retrofitted in days, with an end product that looks the same as conventional masonry block.
"The difference is not obvious and that is one of our selling features," Mr. Niven says. "It is the same, but different."
According to the company, the production of 100,000 green concrete blocks used to build a school would absorb as much carbon dioxide as is used in making 700,000 cans of soda pop.
Cement industry officials say green concrete is one initiative, among many, to shrink the carbon footprint of producers.
"When you are looking for opportunities to improve sustainability in the building or infrastructure sector you have to take a life-cycle approach," says Adam Auer, director of sustainability and stakeholder relations for the Cement Association of Canada. "When you place CarbonCure and other technology in that [life-cycle] context you see it as an important part of a much larger puzzle to improving the sustainability of our built environment."
His association estimates the industry has reduced the greenhouse gas profile of cement by about 10 per cent over the past two decades.
Meanwhile, the Canada Green Building Council plans to update its LEED rating system in June to provide more information about building materials using life cycle assessments and environmental product declarations.
"We are starting to look at it now so that manufacturers and suppliers can start to understand what the impact is from the product so that specifiers [who recommend construction materials] and architects can use them," says Thomas Mueller, council president.
With new buildings increasingly designed either for LEED gold or platinum status in energy efficiency, he says, "The whole building community is starting to pay more attention to the materials."
That's the case for Brampton Brick, an Ontario-based manufacturer of brick and brick and cement for residential and commercial customers that recently installed CarbonCure's technology at one facility and is currently retrofitting a plant in Brampton.
"Our [company] focus is to continuously look for sustainable products … anything to make it greener," says Brampton Brick chief operating officer Dave Carter. He says CarbonCure's technology allows Brampton Brick to uses less cement and cure blocks at a lower temperature, offsetting the cost of carbon dioxide.
He says a green concrete block costs as the same as – or at most a few pennies more than – a conventional masonry block. Commercial customers have started to write green concrete specifications for projects slated to start in the next few months.
Embracing green concrete is a bottom-line issue for Mr. Carter. "If you don't, other competitive building products will take your market share."