Fact for September 12, 2008 – concrete or cement?
It’s probably one of those things you figured you knew because everyone does, but then pressed to explain it you are utterly lost: what is the difference between concrete and cement? Quite simply, cement is some dry material (there are a variety of types) to which water is added to make concrete or mortar. Sometimes the terms are used interchangeably but this is not correct. Part of the problem is that the word ‘cement’ comes from the Roman word ‘opus caementicium’ that was used to describe concrete-like masonry. In any case, depending on the source, either the Egyptians or the Romans are credited with the discovery of concrete and cement though it was the Romans who first put them to wide use. In any case, it was in use by at least the third century BC which is partly why so many Roman buildings are still around. Oddly enough the secret of concrete (not necessarily cement) was lost for 1300 years until it was rediscovered by John Smeaton in 1756.