By Sharon Adarlo
Claire White, an assistant professor of civil and environmental engineering and the Andlinger Center for Energy and the Environment at Princeton University, recently received a three-year grant from the National Science Foundation (NSF) to investigate and optimize the durability of a greener alternative to Portland cement for use at high temperatures, above approximately 500 degrees Celsius.
White will look at an alternative cement composite made from fly ash, a byproduct of coal power plants, to replace Portland cement, a fundamental constituent in concrete and whose production emits one ton of carbon dioxide for every ton produced, accounting for five to eight percent of global carbon dioxide emissions. Portland cement does not perform well at high temperatures. White and her research team are looking to test this alternative cement, made via chemical-activation, for use in fire walls or in kilns, furnaces, and other high temperature applications.
Besides testing at high temperatures, White will investigate the carbonation resistance of this green cement. Portland cement and green cement alternatives can degrade in the presence of atmospheric and industrially-generated carbon dioxide – a process called carbonation. Researchers know more about the impact of carbon dioxide on Portland cement, but less about fly ash composites.
“We need to know more about the durability of sustainable alternatives to Portland cement, which needs to be reduced due its large contribution to human-made carbon dioxide emissions. This research is crucial to uncover the materials’ properties and improve their performance,” said White.
Research will dive deep into the molecular properties of the fly ash composite. For the experiments, White will use a synchrotron, a particle accelerator that generates electromagnetic radiation for image analysis and materials characterization.
In 2016, White was awarded a separate NSF grant, a five-year CAREER grant to investigate more sustainable and resilient alternatives to Portland cement. In that project, her research group is looking at the long-term durability of alternative cements made from byproducts originating from various industries, including the aforementioned fly ash, and blast furnace slag (also known as alkali-activated slag), a glass-like material that is a byproduct of steel production.