Opus caementicium exposed in a characteristic Roman arch. In contrast to present day concrete constructions, the concrete used in Roman buildings was typically lined with brick or stone. The Romans made use of concrete thoroughly from three hundred BC to AD 476.[18] Through the Roman Empire, Roman concrete (or opus https://waylonknmkj.theobloggers.com/42131667/5-easy-facts-about-concrete-reinforced-house-described