Opus caementicium exposed in a very characteristic Roman arch. In contrast to contemporary concrete buildings, the concrete used in Roman structures was generally included with brick or stone. The Romans employed concrete thoroughly from 300 BC to Advertisement 476.[eighteen] In the course of the Roman Empire, Roman concrete (or opus https://byd94815.bloggactivo.com/34999573/indicators-on-reinforced-concrete-meaning-you-should-know