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Past Winner
2005 E.W.R. Steacie Memorial Fellowship

Jacques Marchand

Civil Engineering

Université Laval

Jacques Marchand
Jacques Marchand

When U.S. Navy properties are under attack – from seawater – who does the Navy call to save the day? Dr. Jacques Marchand, one of six winners of the 2005 NSERC E.W.R. Steacie Memorial Fellowship.

Big Idea: "Hopefully the NSERC Steacie Fellowship is going to give research on concrete a better name," says Dr. Marchand, a professor of civil engineering and holder of the Canada Research Chair in Service-Life Prediction of Concrete Infrastructure at Université Laval. "Among engineers it's often been seen as a field working with trivial problems."

The Question: Why does concrete fall apart? We've all seen it – cracking building foundations, decaying parking garages, crumbling highway overpasses exposing rusting steel reinforcing rods. Repairing these structures is a huge cost for businesses and governments, not only in Canada but around the world. Yet, concrete is the most abundantly produced artificial material on the planet, with annual global production estimated at about one cubic metre per person. But while it's the construction material of choice, the long-term service-life of concrete structures is often in constant doubt. That's because concrete is under continuous assault from its surroundings. Concrete is a highly porous mixture that's very basic, with a pH of 13.

"Even rainwater with neutral pH is corrosive for concrete," says Dr. Marchand. As a result, chemicals in the environment – primarily salts like chlorides from winter road salts and seawater, and sulphates in the soil – penetrate into the concrete causing it to weaken, and in some cases expand and crack.

Research at the Edge: "We're trying to find ways to make concrete more durable and to be able to predict this durability," says Dr. Marchand, whose immediate family includes eight engineers and architects and whose father was the former head of Quebec City's engineering department.

To do this, his lab has turned to computer modeling. They've developed the world's leading computational tools to predict the service life of concrete structures. The main tool is STADIUM, a mathematical model for calculating the impact of chemical corrosion on concrete structures. The model is being used to estimate the survival of structures around the world, including many ocean-front ones owned by the U.S. Navy.

In one of its most high-profile applications, STADIUM was used after 9/11 to assess the damage to the former Deutsche Bank Building at 130 Liberty Street adjacent to the collapsed South Tower. When the South Tower fell it crushed a large diesel fuel tank. The fuel flooded the basement and soil surrounding 130 Liberty Street. What was the impact of this contamination on the concrete foundation's durability? Engineers took deep cores of the concrete foundation and turned the results over to Dr. Marchand. "We ran the model and the only way we could explain the penetration of the diesel fuel deep into the concrete was that there was microcracking," he says. And indeed, additional testing of the foundation revealed the microcracking. The building is now being "deconstructed."

Through Groupe SEM, a successful 25-person Université Laval-related civil engineering consulting R&D group, of which Dr. Marchand is President, he's now developing SUMMA, a computational model to predict the impact of freeze-thaw cycles on concrete durability. The research is supported by more than $2 million in funding from a consortium including the U.S. Bureau of Reclamation, which is concerned about the durability of the numerous large concrete hydro electricity dams it manages in the western U.S.

The Next Step: Dr. Marchand's research as an NSERC Steacie Fellow will focus on extending the predictive powers of his computational models. "STADIUM tells you how penetrating chemicals will change the material, but it's not currently able to predict if these changes will lead to cracking," he says. This research will include experiments to study the movement and behaviour of chemicals in concrete's tiniest, nano-scale pores. It's concrete research that will involve peering into the material with high-tech imaging tools from nuclear magnetic resonance to X-ray diffraction and ultrasound.

As a result of this research, says Dr. Marchand, builders and other users of cement and concrete will be better able than ever to anticipate a long and healthy life for their structures.

"You wouldn't believe how many different types of cement there are on the market," he says. "Our models are very sensitive to the type of cement, and as the models improve we'll be able to use better and better science to select and create cements to produce reliable engineering solutions."