Opus caementicium exposed in a very characteristic Roman arch. In distinction to modern concrete buildings, the concrete used in Roman structures was typically lined with brick or stone. The Romans used concrete thoroughly from three hundred BC to Advert 476.[18] In the Roman Empire, Roman concrete (or opus caementicium) was https://historyofjudo70471.blog-kids.com/36013164/getting-my-concrete-reinforced-wire-to-work