A Civil Engineering Renaissance

Civil engineering is like Converse sneakers—its popularity has ebbed and flowed over the decades.

The profession received a boost in the U.S. in the 1930s, for example, after the New Deal: The massive investment sparked plans to build the Hoover and Chickamauga Dams, workers began to carve out the Lincoln Tunnel, and the new Bay Bridge, once completed, spanned more than eight miles of water between San Francisco and Alameda County. 

The golden age of public works stretched well into the 1950s, but between the first miles of I-40s construction in 1957 and its last in 1997, the bloom came off the rose. The Cold War and the Space Race, and the engineering technologies they spawned, gave mechanical engineering a leg up. And Silicon Valley and the rise of electrical and computer engineers were not far behind.

But it seems that civil engineers everywhere are lacing up their Chucks once again and preparing to step back into the spotlight. As Todd Bridges, professor of the practice in resilient and sustainable systems at the University of Georgia’s College of Engineering said at a recent Duke symposium, “I’d like to think that we’re entering a renaissance period in civil engineering with the opportunities that are before us.” said Todd Bridges, professor of practice in resilient and sustainable systems at the University of Georgia’s College of Engineering. That’s because existential threats like climate change are knocking at the door, and civil engineers are uniquely prepared to meet them.

“We are working on so many climate-related challenges,” said Laura Dalton, assistant professor of civil and environmental engineering, whose research includes designing new sustainable materials as alternatives to traditional cement, which is a major contributor to climate change. “Petroleum engineering was the big thing for a while, but now there is a shift away from bringing resources out of the ground, and instead wanting to store carbon dioxide there. It’s a similar science; one being studied on the civil side of the engineering spectrum.”

Dalton’s first undergraduate training was in graphic design and mathematics, and her early ambition was to become an architect. It was her later involvement with the American Society of Civil Engineers (ASCE), and the society’s concrete canoe competition, that captured her imagination and steered her toward civil engineering. The competition challenges teams to design and race vessels made of ultralight concrete mixes, which delighted Dalton. “You’re making concrete that floats. It’s completely counterintuitive to “real-world” applications for concrete,” she explained.

Her participation in the competition led to an internship at the National Energy Technology Laboratory, where her group X-ray computed tomography scanned foamed cements as the material cured to “see” how its bubble-laden structure evolved over time. Being able to visualize such a complex physical process was right up Dalton’s alley—a marriage of math and design. And studying the material and envisioning new forms for its composition showed her an avenue to make a real difference to mitigating the pace of climate change. And studying the material and envisioning new forms for its composition showed her an avenue to make a real difference to mitigating the pace of climate change.

That’s because to chemically break down the limestone and shale needed to make portland cement, the rocks are heated in a kiln with fossil fuels to temperatures of around 2700 degrees Fahrenheit. Portland cement and concrete production accounts for nearly 10% of the world’s total human-caused carbon dioxide emissions, according to a February 2023 article in Scientific American.

The problem has created a huge target for ambitious startups exploring whether a material other than limestone—one with similar properties that does not contain carbon dioxide—could be subbed into the recipe. Dalton is looking into a high-magnesium rock called olivine, which is abundant in North Carolina. On beaches, the ocean sequesters carbon dioxide from the rock as it weathers, and Dalton is interested in whether a similar process can be replicated in concrete to transform it from a carbon producer to a carbon sink.

“I’ve had so many students wanting to work with me on these problems—many who aren’t majoring in civil engineering,” said Dalton. “But these are the problems civil engineers are working on and trying to do, not just in a lab, but large-scale, in real life. And I don’t foresee that changing for the next three decades.”

Across Harrington Engineering Quad, Manolis Veveakis, professor of civil and environmental engineering, is also working on projects that are intertwined with climate change. His specialty—geomechanics—could contribute to more efficient and sustainable energy use on Duke’s campus, for starters.

Last year, Veveakis worked on an exploratory borehole penetrating hundreds of feet below ground in the middle of Central Campus. Veveakis and collaborators in the Nicholas School of the Environment are investigating the geological materials sitting under campus where water could be stored and extracted to heat and cool buildings across campus. Veveakis’s lab must characterize the segments of rock cored from the earth to discover whether it’s permeable enough to transport the cooled or heated water back to the surface. If it works, this strategy could help Duke achieve its goal of carbon neutrality; moreover, the same tactic could be used in geologically similar areas spanning much of the East Coast.

The lab’s focus on the characterization of rocks and soil is proving valuable in other areas of climate mitigation research as well—specifically, into how changes in precipitation are affecting unstable slopes around the world and triggering devastating landslides.

“We’re combining modeling and field experiments with sensors in Europe and on the West Coast, in California,” said Veveakis. “And we’re using a huge centrifuge in Colorado to test soil susceptibility to landslides.”

The centrifuge mimics an environmental condition called aggravated loading, which is something that increases the total weight of the soil—something like intense precipitation. Instead of increasing weight, the centrifuge increases gravity. Modifying the centrifuge with a thermal chamber will allow researchers to control both temperature and humidity in the experiment.

“We want to quantify those effects in different types of soils,” said Veveakis. “That’s what will happen in the lab. And then the idea is to find ways to mitigate the detrimental effects to the ground’s stability.”

All of those experiments can be done in the lab while the sensors in the field collect the years’ worth of data needed to deploy strategies in real life—strategies like drilling boreholes into the hillsides and injecting nanotubes to re-engineer the zones sliding against each other during a landslide. “With advanced modeling, you can find the unstable areas. The mountain typically doesn’t move uniformly, so you don’t need to stop the entire thing,” explained Veveakis. “You can think of it as creating a layer of sandpaper to add friction between the two zones.”

“You don’t have to be a chemical engineer or a petroleum engineer to tackle climate change,” said Dalton. “That, I think, is going to be a big part of civil engineering moving forward. And learning how to characterize the things we see in person is unique to Duke. The balance of laboratory and computational skills that are taught here is unlike other institutions.”

Emblematic of the computational skills found at Duke is the work of Johann Guilleminot, the Paul Ruffin Scarborough Associate Professor of Environmental and Civil Engineering. Since 2017, Guilleminot has partnered with researchers across the school to strengthen their computational models by adding uncertainty quantification into computational mechanics and materials science, as well as on topics at the interface between these fields.

In various scientific disciplines, researchers can try to predict the future in two ways. One is to observe the way systems and objects behave in given conditions and build equations that accurately describe those observations. The second is to build equations and models from the ground up, capturing the nuances and fluctuations of physical interactions at the smallest levels so that it can accurately describe what will happen under any condition.

The second path is generally much more difficult and computationally intensive, but that doesn’t stop Guilleminot from walking it.

“When you describe physics at the atomistic scale, you have different models you can select from,” explained Guilleminot. “We try to account for that variability and enrich a model’s predictive ability by not focusing on a single approach or dataset.”

One example that is obviously connected to climate change is trying to predict the path of a hurricane. Forecast maps always include at least 10 different paths that the storm could take, each produced by a different model. By taking a holistic approach when looking at all of these potential outcomes together, forecasters can get a better estimate of what will actually happen.

But researchers rarely have a dozen or more models to pull from. Often there are less than a handful, which limits their accuracy because of their limited ability to cover a wide range of possibilities. Guilleminot’s work essentially infuses that limited range of computational modeling with additional variability to create the same results that having a dozen or more models to draw from could produce.

“The techniques we’re developing are trying to extract the most meaningful information out of these existing models and enhance their predictions to make them more accurate and reliable,” said Guilleminot.

The applications of strengthening computational models essentially have no bounds. Besides directly applying to the carbon-sequestering concrete and landslide-predicting calculations mentioned above, Guilleminot works with materials scientists on understanding how new types of batteries store and transport energy.

His work also extends well beyond the walls of civil and environmental pursuits, finding applications in biomedical engineering as well. He has worked on projects to account for an individual artery’s geometry and internal integrity in predicting its response to heart surgeries to implant shunts or stents. His approaches have been used to map the boundaries of gray and white matter in a person’s brain more accurately to optimize transcranial magnetic stimulation therapies. And through a collaboration with Ken Gall, professor of mechanical engineering and materials science, he has solidified models of complex, 3D-printed bone implants that minimize their weight while maximizing their strength and ability to allow bone and blood vessels to grow into them.

“This type of computational modeling work extends into most any field, but at the same time, it is a new and critical facet of civil and environmental engineering,” said Guilleminot. “When I’m showing the broad scope of what we do, from the brain to arteries and rib cages, people are like, ‘Wow, that’s civil engineering?’ And yes…yes it is.”