npr: sciencefriday: Researchers are trying to understand why…



Researchers are trying to understand why ancient Roman concrete is exceptionally durable.

Over two thousand years ago, the ancient Romans built piers, breakwaters, and other structures out of concrete—and some of those structures still stand today. Now, researchers are trying to understand the chemical and geological processes that work together to give that ancient concrete such durability. Using microscopy, x-ray diffraction, and spectroscopic techniques, they’ve developed a map of the crystalline microstructures within the concrete. According to their research, a slow infusion of seawater into concrete made with a type of volcanic ash found near Rome gradually creates crystals of a material called aluminous tobermorite, which actually strengthens the concrete as it ages.

Marie Jackson, a geology and geophysics research professor and one of the authors of a report on the work, says that understanding Roman concrete could give modern materials scientists ideas for how to strengthen modern structures, and could even lead to new materials, such as concretes that soak up and trap nuclear waste.

Photo by THINK Global School/flickr/CC BY-NC-ND 2.0

Research that is millennia in the making. -Emily