Concrete has existed in some form or other since civilization was knee-high to a Roman colosseum. As History details, in ancient Rome, concrete consisted of volcanic ash and lime. In the millennia that followed, humanity has largely failed to improve on volcanic concrete. In fact, the predominant modern version is worse. Known as Portland cement, modern concrete combines clay and limestone to create a brittle building material that lacks staying power. It doesn’t hold up well in seawater and has “a service life of less than 50 years.” Via ScienceDirect, Portland cement is so prone to cracking that fibers have to be added to bolster its durability.

Modern concrete also sucks at being green, and not just because of its gray color. Professor of civil and environmental engineering Paulo Monteiro told History that Portland cement “accounts for 7 percent of the carbon dioxide that industry puts into the air.” And it’s a pretty prevalent construction material, with 19 billion tons being used each year. Gosh, wouldn’t it be nifty if modern people created better concrete without having to rip off the ancient Romans? A group of Colorado researchers seem to think so. In fact, they created concrete so green that it’s actually alive.

The life of building blocks

College of Engineering and Applied Science at Colorado University Boulder