Caleb Lunsford ’23


Civil and Environmental Engineering

Project Title

Crack Identification in Alkali-activated Slag Cements

Presentation Link

View Caleb's Presentation

Certificate(s): Architecture and Engineering

I studied the composition and cracking of alkali-activated slag (AAS) cements, an alternative to portland cements with significantly reduced carbon emissions. They also have the potential to be as strong as, or stronger than, portland cements; however, the specific properties of AAS vary significantly depending on their precise chemical composition. I focused on how the addition of zinc oxide impacts cracking as the cement dries. I used X-ray microtomography scanning files to reconstruct two- and three-dimensional representations of several AAS cement samples with different compositions. I then processed the reconstructions to determine how much of the sample’s volume was composed of cracks. Finally, I determined the distribution of cracks throughout the samples and compared how the different cement compositions impacted crack formation. Throughout my internship, I became familiar with ongoing research in the areas of alkali-activated materials and image-based crack identification. I was struck by the interdisciplinary nature of the project and have been prompted to consider how my major and career can interact with other fields.

Internship Year


Project Category

Innovation and a New Energy Future


Sustainable Cements Group, Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment, Princeton University


Claire White, Associate Professor of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment; Yige Zhang, Postdoctoral Research Associate, Civil and Environmental Engineering