Opus caementicium exposed in a characteristic Roman arch. In distinction to modern-day concrete structures, the concrete used in Roman structures was typically covered with brick or stone. The Romans applied concrete thoroughly from 300 BC to Advertisement 476.[eighteen] Throughout the Roman Empire, Roman concrete (or opus caementicium) was comprised of https://reid9122k.theideasblog.com/36328570/fascination-about-concrete-reinforced-steel