The concrete, not the clay

Cracks inevitably appear in concrete especially after several years or decades in place. Now, researchers from the Paul Scherrer Institute PSI and Empa in Switzerland have solved the structure of the material produced in the course of the so-called concrete disease, or AAR (the alkali-aggregate reaction that occurs as moisture ingresses the concrete) at the atomic level reveal a novel crystalline sheet-silicate structure for the material. The work could lead to more durable concrete in the future.