Year of Invention: 285
What Is It? The component of concrete that acts as the binding and hardening
agent, locking sand and gravel into a solid mass.
Who Invented It? Roman engineers (in Pozzuoli, Italy)
Cement, and its construction form—concrete—have been the primary building material for cities, bridges, cathedrals, massive hydroelectric dams, skyscrapers, aqueducts, sewers, highways and roads, etc., for 2,000 years.
Launch pads for every rocket blasted into space have been made of concrete. Every major European cathedral, the great building wonder of the Middle Ages, was built of concrete. Roman bridges and aqueducts that have survived for over 2,000 years were built of concrete.
The idea of mixing gravel and sand with some binder is at least 7,000 years old. Crude concrete-like floor slabs have been found in huts along the Danube River dating to 5000 B.C. The Egyptians had developed a cement-like material to use as a binder for concrete construction by 3000 B.C. But Egyptian cement lacked the strength and hardness to be durable. They used a mix of lime and gypsum (a calcium rich mineral) as their binder. It produced concrete with low strength and a nasty tendency to crack and crumble after only a few years.
The word cement comes from the Latin word caementum, meaning rough stones and rubble. Cement originally referred to any mixture of broken stone held loosely together by a binding material of lime, clay, gypsum, and sand. It was the Romans who shifted the word cement to mean only the binding material, They then invented the word concrete to refer to the entire mixture of sand, gravel, water, and the binding agent—cement.
Early Roman engineers (around 300 B.C.) copied their cement and concrete techniques from Greek and Egyptian builders, using the proportions of cement, sand, gravel, and water that were common in these two countries. Limestone was burned in ovens and then ground