Tiziana Vanorio: Low-carbon cement for a better world

Stanford scientist Tiziana Vanorio was a teenager when hundreds of tremors struck her hometown of Pozzuoli, Italy, which is located inside a large volcanic crater near Naples. Fearing that the unrest might indicate an imminent eruption, officials ordered the evacuation of tens of thousands of residents, including Vanorio and her family.

The rumblings, as it turned out, did not presage an eruption, and Pozzuoli residents were permitted to return two years later. But the experience sparked Vanorio’s curiosity about Earth and served as the catalyst of her career. “I started to reflect on nature, and how it can affect people in very tangible ways,” Vanorio said.

That curiosity led her to pursue a PhD in geophysics volcanology at the University of Naples, and later postdoctoral work at Stanford. Focusing on rock physics, Vanorio for decades has applied her knowledge to answer questions about how rocks deform and fracture, and how carbon dioxide, steam, and other fluids move through reservoir rocks.

Now an associate professor of Earth and Planetary Sciences at the Stanford Doerr School of Sustainability, Vanorio is currently leading work on a new cement – inspired by how rocks bind together – that can reduce carbon emissions from concrete, one of the largest industrial contributors to global warming. “I want my research to be applied to something that serves a purpose,” she said. That ambition stems from her upbringing in a family of public servants who instilled values of ethics, justice, active citizenship, and concern for the well-being of others, Vanorio explained. “It’s not just about improving the climate, but also about finding solutions to coexist peacefully with others on the only planet we have.”

Modern concrete production leaves an enormous carbon footprint that begins with cement, the powdery binding ingredient made, in part, from limestone. After being mined and processed with other materials, limestone rocks are exposed to high temperature, usually generated by burning fossil fuels. But it’s the decomposition of the limestone rock that releases most of the carbon. Each year, the mining of about 2 billion tons of limestone rocks for cement results in the emission of about 1,300 megatons of CO₂, a figure roughly equivalent to the CO₂ emissions from all the cars in the United States in a year.

At Stanford, Vanorio’s research group has been studying the controls on natural cementation, including the cementation of earthen materials from volcanic rocks, and their resulting mechanical properties. The team is now applying insights from this research to create what Vanorio calls “geomimetic cement,” a new blend of volcanic rock-based cement that strongly reduces the need for conventional limestone and its associated emissions. “I know I can use a different rock blend to make cement that mimics the way rocks cement in nature,” Vanorio said.

As she works with colleagues across campus to understand cementation at nanoscale and refine the production process, Vanorio remains motivated by the much bigger picture – in which she believes the ability to develop roads, bridges, buildings, and other vital infrastructure with fewer emissions or to develop a more resilient cement that makes gas wells less leaky might also advance goals of socioeconomic equality, national security, and food security. “I view this work as a public service,” Vanorio said.