Making buildings safer by focusing on why they can fall — over time

The recent collapse of the condo building in Florida served as a dire warning for the nation’s aging infrastructure problem and the deadly consequences that can result. Sarah Orton at the University of Missouri is working to learn more about why buildings fall and how to prevent disastrous collapses from occurring. Now, she’s looking into how the influence of time can contribute to a building’s collapse, using a more than $200,000 grant from the National Science Foundation.

“Concrete has a time dependent effect,” said Orton, who is an associate professor in the Civil and Engineering Department. “The strength of concrete under a high load for a long period of time is less than that under a short period. Here, we’re trying to understand how time contributes, and once we get that figured out, we can start looking at other things, such as corrosion, to really understand the overall life span of a structure.”

Orton’s background deals specifically with reinforced concrete building materials — steel rods surrounded by concrete. It’s a commonly-used building material because it’s strong and can be mass-produced. But Orton’s primary focus with this grant is not on the strengths of these building materials. Instead, she wants to determine their breaking points under load-bearing situations, or the extreme point just before a collapse occurs. That involves conducting thousands of hours of laboratory tests to put different types of stressors on concrete slabs until they break apart. Some of her tests can take months to complete.

The project, which is estimated to be completed in summer 2022, will include the ability to develop computer modeling to help show how different types of large-scale building collapses can happen. Orton’s findings will also be added to the results of her collaborator’s project by Ying Tian at the University of Nevada Las Vegas, which was awarded a separate grant from the National Science Foundation of more than $200,000.

The grants, “Collaborative Research: Time-Dependent Response of Reinforced Concrete Structures Near Collapse,” were awarded by the National Science Foundation (1760915 and 1762362).