Concrete is the most used construction material worldwide but how did it come to be? In this article, we take a look at the early forms of concrete, mortar and cement.
First Examples of Mortar and Cement The earliest known occurrence of cement (an ingredient in concrete) happened naturally, around twelve million years ago in Israel. Oil shale, which was located near to a bed of limestone started to burn due to natural causes, thus forming a deposit of cement compounds. The compounds were discovered and investigated by Israeli geologists.
Throughout history, we can see that various mortars, binders and cement like materials were used to create structures all over the world. Ancient Egyptians used mud and straw as well as gypsum and lime mortars to build the great pyramids. During the construction of the great wall of china, the Chinese used cementitious materials to bind bamboo. Ancient Greeks used lime mortars and Babylonians used asphalt bitumen to bind bricks and stones.
In 1300BC we see another ancient form of cement, this time used by Middle Eastern builders. The builders would use burned limestone to thinly coat the walls of their pounded clay fortresses. This thin coating reacted with the air forming a hard shell which acted as a layer of protection on the building.
First Examples of Concrete
The first civilisation recorded to create concrete structures however existed long before any of the examples above. In 6500BC The Nabateans, a highly skilled Arab people created concrete housing structures, floors and even underground cisterns after discovering the advantages of hydraulic lime. While the Nabateans were the first people to create concrete structures such as housing, a discovery was made in 1985 of a concrete floor in Israel, which was found to date back to 7000BC, 1500 years before the Nabateans.
The next example we see of concrete in history is ancient Rome during 300BC TO 476AD. Pliny the elder, a roman author, naturalist and philosopher reported a mortar mixture containing one part lime to four parts sand. Vitruvius, the roman architect and civil military engineer reported another mixture of two parts pozzolana cement to one part lime. Romans were also reported to add special admixtures to their cement mixtures, just as we do today however these mixtures were quite a lot different. Romans would use animal derivatives such as blood, fat and milk to improve the frost resistance of their mixes.
