Somehow I'm not surprised that this is what turns up when I google Roman concrete: > “Roman concrete is . . . considerably weaker than modern concretes. It’s a

Somehow I'm not surprised that this is what turns up when I google Roman concrete: > “Roman concrete is . . . considerably weaker than modern concretes. It’s approximately ten times weaker,” says Renato Perucchio, a mechanical engineer at the University of Rochester in New York. “What this material is assumed to have is phenomenal resistance over time.” http://www.smithsonianmag.com/history/the-secrets-of-ancient-romes-buildings-234992/?no-ist= http://www.smithsonianmag.com/history/the-secrets-of-ancient...