Concrete often begins to crack and crumble after a few decades of life — but curiously, that hasn’t been the case with many Roman structures. The structures are still standing, exhibiting remarkable durability despite conditions that would destroy modern concrete. One particular structure is the large cylindrical tomb of first-century noblewoman Caecilia Metella. New research from MIT scientists and colleagues published in the Journal of the American Ceramic Society shows that the quality of the concrete of her tomb may exceed that of her male contemporaries’ monuments because of the…