Opus caementicium uncovered in a attribute Roman arch. In contrast to modern-day concrete buildings, the concrete used in Roman structures was typically protected with brick or stone. The Romans employed concrete extensively from 300 BC to Advertisement 476.[eighteen] Throughout the Roman Empire, Roman concrete (or opus caementicium) was constructed from https://thebookmarkage.com/story19746731/5-easy-facts-about-concrete-reinforced-house-described