Early History and Development of Portland Cement

There had been searched for a material that binds stones in a hard and shapely way since the early formations of civilizations. Assyrians and Babylonians used clay for this purpose. Egyptians developed lime and gypsum as a binder material in the constructions like Pyramids.

Greeks developed the binder materials further and finally Romans found the cement which provides constructions with continuous stability.

Most building bases of the Rome style were constructed in the form of a soil mixture with a 3,5 meters deep is some places. Large Rome baths, Colosseum and the big Constantine Basilica built around B.C. 27 are the examples of early Rome architecture in which cement soil mixture was used.

Rome Formula

The secret for the Romans in the success of making cement is based on the mixture of pozzuolana which is an ash from Mountain Vesuvius and dead lime. This process created cement which has the ability to get hard in the water. In the Middle Age this art disappeared and had been kept hidden until we discovered the secret of hydraulic (frozen in the water) cement again.

The repetitious structural failure of Eddystone lighthouse at the Cornwall coast in England resulted in John Smeaton, an English engineer, to make experiments with soil mixtures in fresh and salty water. These tests processed in 1756 showed that the cement made from limestone including considerably much clay froze in the water. Eddystone re-built his lighthouse taking advantage of this invention and this lighthouse had been alive for 126 years without any restoration.

Other researchers making tests in the cement field from 1756 to 1830 include L.J. Vicat and Lesage in France, and Joseph Parker and James Frost in England.

Before and after the Portland cement was invented, much amounts of natural cement was used for a couple of years. The natural cement was produced by burning the natural mixture of lime and clay. Since the components of the natural cement are mixed by the nature itself, the properties of it show variety as the natural sources have.

Aspdin takes out the patent

Joseph Aspdin, a bricklayer in Leeds England, took out the patent for hydraulic cement in 1824 and gave the name Portland Cement to this since it was similar to a stone taken out in the Portland Island, England. The method of Aspdin is based on the mixture prepared by a careful proportioned limestone and clay, making it powder, obtaining clinker by cooking the mixture and grinding this clinker so that it becomes the finished cement.

Today, portland cement is the chemical mixture of calcium, silica, aluminium and iron in predetermined and accurate amounts, as it was in the times of Aspdin.

Cement in the 20th Century

In the beginning of 20th century, two important inventions became facts.

First one is the invention of production principle white cement which is obtained by using kaolin without iron. However, this different composition did not change the fundamental properties of cement by providing a resistance capacity comparable to grey cement.

The year 1908 witnessed the first industrial calcium alimunat which was made from limestone and bauxite. Cement with high aluminium oxide which is resistant to aggressive agents and high temperatures, provided multipurpose usage opportunities such as a high performance binder and chemical reactant in a number of different applications. Today, calcium alimunats are placed on the top of technological development at construction site and they encourage the improvements of a lot of technologic products like special soil mixtures, refractory soil mixtures and other.