An international research team has revealed important clues to the longevity of such Roman architectural marvels as the Pantheon, Trajan’s Markets and the Colosseum. Led by researchers at UC Berkeley, Lawrence Berkeley National Laboratory and Cornell University, the team discovered that the long-term resilience of the concrete is due to the mineralogical changes that occur as the Roman volcanic ash-lime mortar cures. The Romans developed a standard formula for making this mortar about 2,000 years ago. The mortar binds cobble-sized fragments of tuff and brick, and it was used in the concrete walls of many monuments in Rome.

December 15 news release by the University of California at Berkeley. Read more.