Opus caementicium exposed in the characteristic Roman arch. In contrast to fashionable concrete structures, the concrete used in Roman structures was usually lined with brick or stone. The Romans made use of concrete extensively from 300 BC to AD 476.[eighteen] Over the Roman Empire, Roman concrete (or opus caementicium) was https://dominickfcxsn.widblog.com/90642730/helping-the-others-realize-the-advantages-of-concrete-reinforced-with-rebar