Cementing the Future

Ferrier designed the prototype for his Hypergreen skyscraper with ultra-high-performance concrete that can be up to 10 times as strong as the standard fare.

JACQUES FERRIER ARCHITECTURES/IMAGE FERRIER PRODUCTION

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At the R&D labs of steel giant ArcelorMittal in Belgium, for example, researchers are trying to develop thinner, stronger steel that can replace plastic in washing machines and other appliances. They're also experimenting with coatings that are eco-friendly and more effective in fighting corrosion. Dulux Trade, the paint subsidiary of Netherlands-based chemical firm AkzoNobel, this year started selling a new type of paint called Ecosure that sharply reduces the amount of embodied carbon and other so-called volatile organic compounds--and is being heavily marketed as "a new era in sustainability and performance." At the R&D center of French cement giant Lafarge, director Pascal Casanova waxes lyrical about Ductal, a superresilient concrete the center developed that he calls the Formula One of concrete. It's what architect Ferrier used in his 807-ft. (246 m) Hypergreen tower, a project that wouldn't have been possible with regular concrete.

To get a sense of how technological progress is translating into environmental gains, take a trip to the research campus of Lafarge, just outside the French city of Lyons. The world's largest cement company, with sales of $22.5 billion in 2007, Lafarge has set itself the goal by 2010 of cutting its net CO2 emissions for every ton of cement it produces to 20% below the 1990 level. But it is also steaming ahead with research efforts into smarter, stronger and less polluting products, including ultra-high-performance concrete. Research director Casanova traces the path of innovation back to the 1980s, when the first big gains were made in improving the resistance of concrete. In the two decades since, researchers have figured out how to increase that resistance by a factor of 10. "There's been a very important revolution over the past 20 years, and it's not over," Casanova says.

Stronger concrete translates into significant gains for the environment because it can be applied more thinly, consuming considerably fewer raw materials than regular concrete. (The basic mixture includes cement, stone or other aggregate and water.) Moreover, concrete has some properties that make it intrinsically energy-efficient when used in buildings. It insulates well because it's poured and thus doesn't let in wind and water. Its density also means that it stores heat during the day and releases it at night, making it possible to save on air-conditioning and heating. Architects including Ferrier are playing with such possibilities as they design their new buildings. And the ultra-high-performance concretes can be put to surprising uses: in a showroom on the Lafarge campus, there's a table made of concrete that is so thin and elegant that from a distance it looks as though it could be made of marble.

Lafarge is by no means alone. Franz-Josef Ulm, a professor of civil and environmental engineering at Massachusetts Institute of Technology and a concrete expert, says "there's not one single cement company that is not looking at" ways to improve the resistance of concrete. He still sees room for improvement. The next step is to create materials with higher strength but that use the same amount of initial material, says Ulm.