Chemistry in Pictures: Climate-friendly concrete

It’s hard to beat the scale of concrete. Humanity makes 30 billion metric tons per year, mostly through a process that emits massive amounts of CO₂. Researchers and entrepreneurs are working on ways to turn that around and make concrete with a milder impact on climate change. One group is the Polyhedral Structures Laboratory at the University of Pennsylvania, which recently brought their CO₂-absorbing concrete structures to Washington, DC, for the annual summit of the US Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E). The 3D-printed sculpture, which stands about 0.75 meters tall, is meant to demonstrate the mechanical strength of the material and the agility of the 3D-printing technique. The formulation replaces 30% of the cement with porous biominerals that are less carbon intensive to make and enhance the finished concrete’s ability to absorb CO₂ from the air as it cures.

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