The precursor to concrete was invented in about 1300 BC when Middle Eastern builders found that when they coated the outsides of their pounded-clay fortresses and home walls with a thin, damp coating of burned limestone, it reacts chemically with gases in the air to form a hard, protective surface.
Early cementitious composite materials typically included mortar-crushed, burned limestone, sand, and water, which was used for building with stone, as opposed to casting the material in a mold, which is essentially how modern concrete is used.
Early Recording of Concrete
The first concrete-like structures were built by the Nabataea traders or Bedouins who occupied and controlled a series of oases and developed a small empire in the regions of southern Syria and northern Jordan in around 6500 BC. They later discovered the advantages of hydraulic lime that is, the cement that hardens underwater and by 700 BC, they were building kilns to supply mortar for the construction of rubble-wall houses, concrete floors, and underground waterproof cisterns.
3000 BC – Egypt and China
Around 3000 BC, the ancient Egyptians used mud mixed with straw to form bricks. A mud with straw is more similar to adobe than concrete. However, they also used gypsum and lime mortars in building the pyramids, although most of us think of mortar and concrete as two different materials. The Great Pyramid at Giza required about 500,000 tons of mortar, which was used as a bedding material for the casing stones that formed the visible surface of the finished pyramid.
About this same time, the northern Chinese used a form of cement in boat-building and in building the Great Wall. Spectrometer testing has confirmed that a key ingredient in the mortar used in the Great Wall and other ancient Chinese structures was glutenous, sticky rice. Some of these structures have withstood the test of time and have resisted even modern efforts at demolition.
600 BC – Rome
By 600 BC, the Greeks had discovered a natural pozzolan material that developed hydraulic properties when mixed with lime, but the Greeks were nowhere near as prolific in building with concrete as the Romans. By 200 BC, the Romans were building very successfully using concrete, but it wasn’t like the concrete we use today. It was not a plastic, flowing material poured into forms, but more like cemented rubble.
During the Middle Ages, concrete technology crept backward. After the fall of the Roman Empire in 476 AD, the technique for making pozzolan cement was lost until the discovery of manuscripts describing it was found in 1414. This rekindled my interest in building with concrete. It wasn’t until 1793 that the technology took a big leap forward when John Smeaton discovered a more modern method for producing hydraulic lime for cement.
In 1824 Joseph Aspdin invented Portland cement by burning finely ground chalk and clay until the carbon dioxide was removed. In the 19th Century, concrete was used mainly for industrial buildings. The first widespread use of Portland cement in home construction was in England and France between 1850 and 1880 by Francois Coignet, who added steel rods to prevent exterior walls from spreading.