The History of Cement and Concrete
Cement and concrete have a long and illustrious history. From the Ancient Egyptians to modern buildings, both have served as materials for the most astonishing of construction projects. This five-part series tracks how the materials have developed over time.
Part 2: The production of hydraulic cement
Hydraulic cement is created when a chemical reaction takes place between water and the cements (a combination of silica and lime). The Romans had developed a process to create hydraulic cements, but this was lost during the Middle Ages. In fact, it was not until the 17th and 18th centuries that the methods for making hydraulic cements were formalized.
Perhaps the first noted contribution to the development of modern cement was John Smeaton who built a lighthouse in the English Channel that is now known as Smeaton’s Tower. Tidal flows meant that he needed a cements that would set within the twelve-hour cycle. He carried out a number of experiments combining cementitious materials in different quantities until he was successful. This work found that the hydraulic characteristics of the cement were directly related to the clay content of the limestone used in the mix.
Experimentation with different types of cements continued in the following years with different mixes gaining popularity for different building styles. In England, Joseph Aspdin, a bricklayer from Leeds, obtained a patent for his ‘Portland Cement’ in 1824. His process created the first true artificial cements by burning ground limestone and clay together. Aspdin’s substance is noted as being the first step towards the Portland cements known today.