Concrete is a mixture of cement, sand, course aggregate, and water. These materials are mixed in specific proportions according to its designed use.
Many people make the mistake by calling concrete "cement" when cement is the binding agent in concrete.
Concrete is the most used building material in the world. In 2008, the United States alone consumed 93.6 million metric tons of portland cement with annual cement industry shipments currently estimated at $10.0 billion.
So where does cement come from?
I need to start this with a quick history lesson. Back in the 19th century, a bricklayer named Joseph Aspdin of Leeds, England first made portland cement by burning powdered limestone and clay on his kitchen stove. He named it Portland cement because it produced a concrete that resembled the color of the natural limestone quarried on the Isle of Portland, an island in the English Channel. Little did he know that his mixture would revolutionize the building industry throughout the world over.
The production of portland cement starts with mining limestone rock. The rock is then pulverized and put through a furnace where it reaches temperatures of around 2,700 degrees F. The heat changes the chemical properties of the rock which is then further refined into such a fine powder that it will pass through a sieve that would hold water. In fact, one pound of cement contains 150 billion grains.
Mix, Deliver, and Install
Local concrete companies take portland cement and mix it with locally mined sand, gravel, and water. They then deliver the concrete mixture in specially designed concrete trucks to concrete installers like us. We mold the concrete into specific designs, shapes, and patterns either for structural purposes like footings and foundations or cosmetic and usable surfaces like concrete driveways, garages, patios, and steps.
As you can see, the end product of cement, which is concrete, is all around us. Our lives and the world as we know it would not be the same without concrete.