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Re-imagining Infrastructure: Gianluca Cusatis Envisions Roads, Bridges of the Future

It’s just stone, sand, and water, but in many ways it’s the bedrock of modern society.
From bridges to parking garages to sewer pipes, concrete remains the go-to material for things that need to stay strong and last long. Unfortunately, the material is also prone to cracking and crumbling; it’s expensive to repair, takes significant amounts of energy to create, and doesn’t last nearly as long as we’d like it to.

These are some of the problems that Gianluca Cusatis, associate professor of civil and environmental engineering at the McCormick School of Engineering, is dedicating his career to solving.

Cusatis, who came to McCormick in 2011, works to develop a new generation of infrastructure materials that are longer-lasting and more sustainable — an area of tremendous importance, both technologically and economically.

“It’s extremely important that we develop better infrastructure materials,” said Cusatis. “Look at bridges, for instance. Our concrete bridges today were built to last 100 years, but after just 40 they are deteriorated from corrosion and other chemical reactions.

“All these bridges must be retrofitted or replaced at a huge cost, not to mention the safety concerns,” he added. “With more durable materials, we can have bridges that are safer and will last twice as long.”

A native of Italy, Cusatis received his PhD from the Politecnico di Milano in Milan. While there, he studied under structural engineering expert Luigi Cedolin, who in 1991 co-authored the book Stability of Structures with McCormick’s Zdenek Bazant. He spent six years teaching at Rensselaer Polytechnic Institute, where he performed research on heterogeneous and quasi-brittle materials, concrete and reinforced concrete modeling, and infrastructure materials.

For much of his career, Cusatis’ work was solely analytical and computational in nature; he developed computer models to explain how structures behave and to determine how materials could be made stronger and more durable. Like other computationalists, Cusatis would read papers published by his laboratory counterparts (the “experimentalists”), but the two camps remained separate in the structural engineering world.

But since arriving at Northwestern last year, Cusatis has begun to branch out into the laboratory — thanks to his department’s experimental lab and a long tradition of cement research by faculty such as Bazant and Surendra Shah.

“In modern engineering and materials science, the time in which you do experiments in a vacuum or do computations just on paper is over,” Cusatis said. “You must be able to do the modeling and also to do experiments that you can control. There must be a close integration of these different fields.”

Cusatis is presently working to develop a high-performance concrete enhanced with steel and synthetic fibers that is crack-resistant and 10 times stronger than the standard variety; with this added strength, he explains, structures could be built with much less material. Other projects include examining the aging of U.S. dams for the Department of Homeland Security.

But formulating the material is just the beginning; with people’s lives depending upon its stability, a new concrete must endure years of testing before it can be used, as it has mechanical properties distinctly different from the ones of typical concrete. That process raises numerous questions: When it comes to construction guidelines, what sort of rules must we follow? Ones like those created for concrete? Or guidelines more like those for steel?

“Ultimately my goal is to say, ‘OK, now we have these new materials, and they open up all these new possibilities,’” Cusatis said. “Now let’s see how we can actually use them for real civil engineering applications.”