Development of Portland Cement – Landmarks

From ancient times, human civilizations have searched for ways and mixtures to join stones and other raw materials into a solid form useful for constructing purposes. And, with many trials the Assyrians and Babylonians were the first to pick up the concept by using clay as a natural binder. During the same time, the Egyptians discovered lime and gypsum, which highly contributed to the building of the famous pyramids.

The Greeks also went on to make further contributions toward the construction realm. Yet with advanced cements from the Romans, who developed a highly durable cement, building became much more sturdy. With such a discovery, renowned Roman structures were built, such as the famous Roman Baths, constructed around 27 B.C. The Coliseum and Constantine’s vast basilica are other examples of ancient Roman architecture which made use of cement binders.

The secret of success of the Roman’s caementum came from a combination of lime with “pozolana”, a volcanic ash from Mount Vesuvius in the area around Pozzuoli. This process yielded cement, which was more resistant to salt and freshwater. The craft was lost during the Middle Ages and was only revived by the enterprising scientists of the eighteenth century who rediscovered the concept of hydraulic cement which hardens even when submersed in water.

John Smeaton, an English engineer, was faced with the challenge of building a solid structure for Eddystone lighthouse on the Cornish Coast. He undertook a series of experiments with binders in fresh water as well as salt water and discovered cement based on limestone. Limestone mixed with the right proportion of clay hardened under water, for that reason it was used in building the lighthouse in 1759. The original cement lasted 126 years without needing any reinforcement!