A bag of cement weighs 94 pounds. Concrete mix typically uses five bags of cement, or 470 pounds, per yard of concrete to be poured. Concrete mix includes rocks and sand along with cement.
Cement is a masonry binding agent that hardens upon drying. An early version of cement that included sand, gravel and lime was used in ancient Mesopotamia in 3,000 B.C. Some structures built with a similar mixture by ancient engineers, including the Pantheon in Rome, are still standing as of 2014. The first cement similar to modern Portland cement was made by Englishman William Aspdin in the 1840s.