What is concrete used to create? How is cement made? And how can we reinvent this ubiquitous material in ways that reduce or potentially eliminate its carbon footprint? Minute Earth explains in The Problem with Concrete, presented in partnership with Bill and Melinda Gates.
Some history from Building a Better World With Green Cement in Smithsonian Magazine:
People have been trying to build a better cement since just about the beginning of history. More than 2,000 years ago, the Romans devised a mixture of lime, volcanic ash and chunks of stone to form concrete, which was used to make harbors, monuments and buildings—the glue of early cities—including the Pantheon and the Colosseum. In the 1820s, in Leeds, England, about 200 miles from Imperial College, a stone mason named Joseph Aspdin invented modern cement. Aspdin heated a concoction of finely ground limestone and clay in his kitchen. After he added water, the mixture hardened. Voilà—the building block of the Industrial Revolution was born. Because the material looked like a popular building stone from the Isle of Portland, Aspdin called his invention Portland cement. The patent, issued in 1824, was for “an improvement in the mode of producing an artificial stone.”
Related videos: Creating wood ash cement from scratch, an experiment with Primitive Technology, and concrete does not dry out with Minute Physics.
Related reading: What’s the difference between cement and concrete?
Plus, a potential solution with some seashell inspiration: Growing cement bricks with bacteria.