Concrete’s large carbon footprint—that is, the amount of carbon dioxide emitted during the cement manufacturing process—is estimated to be 5% of industrial CO2 emissions, a source of concern in the battle against human-caused climate change. But last month, an international research team reported that substantial quantities of CO2 are reabsorbed, or sequestered, by cement-based products over their life cycle. Concrete, in fact, acts as a carbon sink. And that makes it more attractive as a material choice when it comes to battling global warming and limiting greenhouse gasses.
The study, published in Nature Geoscience, a monthly, peer-reviewed scientific journal, was led by Fengming Xi of the Chinese Academy of Sciences, with researchers from the California Institute of Technology, the University of California Irvine and the United Kingdom’s University of East Anglia. “We are not the first to observe that cement absorbs CO2,” says Steven J. Davis, UCI associate professor of earth system science, who participated in the study. But “no one has ever bothered to tally up how much carbon is being absorbed in all of the concrete in the world. That’s what we’ve added.”
Because it can moderate the damaging effects of earthquakes, base-isolation is a technique used primarily in seismically active regions. ENR takes a look at some of the largest applications of base-isolation technologies in the world.