Add Yahoo as a preferred source to see more of our stories on Google. Researchers still puzzle over exactly how Roman concrete was made, but they have a few clues, including many of its ingredients ...

Nearly two millennia after the height of the Roman Empire, some of its structures are still standing. These marvels have stood the test of time, including the Pantheon in Rome; the Roman aqueducts in ...

You walk on concrete every day without thinking about it. That sidewalk, your driveway, the foundation of every building around you; it's all made from essentially the same recipe. Funnily enough, ...