Concrete and cement are NOT the same thing.
More Info: Cement is an ingredient in concrete, which is technically a mixture of cement, water, sand or gravel.
What Is Cement?
Portland cement, the main ingredient in concrete, was invented by a British stonemason in 1824. Joseph Aspdin was granted a patent for a mixture of limestone and clay that he ground on his kitchen stovetop that when combined with water hardened to create hydraulic cement. Today, Portland cement is made with a combination of calcium, silicon, aluminum, and iron.
What Is Concrete?
Though many people use the terms interchangeably, concrete and cement are not the same. Cement is only one of the components that make up a concrete mixture. Concrete can have a variety of additions to achieve different textural and structural results, but there are primarily three components necessary to make concrete: water, sand or gravel, and cement to bind it all together.
“Cement vs. Ready Mixed Concrete | The Words are NOT Interchangeable.” Welcome to Schmitzmix.com, the online home of Schmitz Ready Mix. N.p., n.d. Web. 3 Nov. 2011. http://www.schmitzmix.com/press/press1.html
“History & Manufacture of Portland Cement.” Portland Cement Association. N.p., n.d. Web. 2 Nov. 2011. www.cement.org/basics/concretebasics_history.asp
“What is Concrete – Information and Definition – The Concrete Network.” Concrete Design Ideas, Contractors and Pictures – The Concrete Network. N.p., n.d. Web. 3 Nov. 2011. <http://www.concretenetwork.com/concrete.html>