Academic Minute Podcast
Thomas Petersen, University of Southern California – Concrete Built Half Our World, But May Be Harming It
On University of Southern California Week: Concrete has been an important part of our world, but at what cost?
Thomas Petersen, assistant professor of civil and environmental engineering, delves in to find out.
Dr. Petersen started working as an Assistant Professor in the Sonny Astani Department of Civil and Environmental Engineering in Fall 2022. Prior to arriving at the University of Southern California, he spent three years as a Senior Research Engineer at ExxonMobil, where he developed technologies to improve the integrity of wells during construction and operation. Specifically, he worked on composite fluid and solid systems that reduce pressure and stress developments in confined, high-temperature, and high-pressure environments. At USC, his research focuses on modeling the electrochemistry and dissolution-precipitation kinetics of reactive, solidifying systems; developing models and experiments to understand the growth in elasticity and internal stresses during cement hydration; and designing composite materials with new functionality for civil engineering applications.
Concrete Built Half Our World, But May Be Harming It
The built environment is made of concrete.
Strong… durable and relatively cheap.
It’s the “most-used” material in the world… after water.
And production of this must-have material belches greenhouse gases into the atmosphere… helping to warm the planet.
To make more sustainable concrete … we’ll need to find alternative materials that have strong binding properties… “without” the heat-intensive process currently used in concrete production.
It’s a complicated material that requires a multi-disciplinary approach… including chemistry, physics and mechanics.
We’re engineering solutions to the concrete mystery … and to make it more eco-friendly.
How? One way is finding alternatives to cement. It’s an essential ingredient in concrete … but it is also one of the main sources of c-oh-two emissions during the production of concrete.
A report from Norway’s center for international climate research has found that cement-making accounts for more than seven percent of all global c-oh-two emissions.
We’re looking at the chemical structure that gives concrete its strength and durability … and exploring how we can mimic those properties without the negative environmental impacts.
Carbon dioxide is emitted in two ways throughout the cement-making process, one from the chemical process itself and the other from heating the chemicals.
Calcium silicate hydrate, or c-s-h, is one of the main contributors of concrete’s high carbon dioxide emission levels. To create it, limestone is taken out of the ground and heated at extremely high temperatures. This process strips carbon dioxide out of the limestone, allowing it to enter the atmosphere.
By understanding how c-s-h operates on a microstructural scale, we can create sustainable alternatives that retain their resilience.
States like California… Colorado… new jersey and New York have already passed legislation supporting/requiring cleaner concrete.
That trend is growing… offering a concrete vision for a cleaner way to produce this vital material.
[Zenodo] – Global CO2 emissions from cement production
[USC Viterbi] – Concrete Built Half Our World, But May Be Harming It. Thomas Petersen Wants to Change That.