what was concrete made out of in ancient rome
Yet structures like the Pantheon and the Colosseum have survived for centuries, often with little to no maintenance. Geologists, archaeologists and engineers are studying the properties of ancient Roman concrete to solve the mystery of its longevity. “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.
So I had a colonoscopy today...found some hemorrhoids, but also found mildly congested mucosa in the cecum.. The doc said they biopsied it but did not mention what could cause this, he seemed to not want to worry me.