The History of Concrete

Cement has been a naturally occurring substance for more than 12 million years. It has been used for construction in various ancient civilizations including the Romans, Egyptians, and the Greeks. During the Roman Empire, Roman concrete was made from quicklime, pozzolana, and an aggregate of pumice. It's widespread use in many Roman structures, a key event in history of architecture termed the Roman Architectural Revolution, freed Roman construction from the restrictions of stone and brick material and allowed for revolutionary new designs both in term of structural complexity and dimension.

After the fall of the Roman Empire, the quality of cementing materials diminished rapidly and didn't reappear again until midway through the Middle Ages. Concrete technology took a huge leap in the 1700s when John Smeaton, an English engineer looking for a building material that would not be adversely affected by water, discovered that some calcinations of limestone produced hydraulic lime, a lime that hardens under water.

Years later, the American inventor Thomas Edison advanced the technology when he introduced the first long kiln in 1902 in his Edison Portland Cement Works in New Village, New Jersey. His kiln was 150 feet long, 70 feet longer than the kilns used at that time, and paved the way for today's kilns that are sometimes more than 500 feet long. Edison received a patent for his kiln in 1909.

Today, concrete is the most frequently used material in the building industry and can be found everywhere in the world -- in roads, buildings, bridges and many other structures. The legacy of concrete is as enduring as the material itself. All around you is evidence of this revolutionary technology and an important part of human history.