Cement ancient

In ancient India, a steel called wootz was made by placing very pure kon ore and wood or other carbonaceous material in a tightly sealed pot or cmcible heated to high temperature for a considerable time. Some of the carbon in the cmcible reduced the kon ore to metallic kon, which absorbed any excess carbon. The resulting kon—carbon alloy was an excellent grade of steel. In a similar way, pieces of low carbon wrought kon were placed in a pot along with a form of carbon and melted to make a fine steel. A variation of this method, in which bars that had been carburized by the cementation process were melted in a sealed pot to make steel of the best quaUty, became known as the cmcible process. 

Before the invention of the Bessemer process for steelmaking in 1856, only the cementation and cmcible processes were of any industrial importance. Although both of the latter processes had been known in the ancient world, thek practice seems to have been abandoned in Europe before the Middle Ages. The cementation process was revived in Belgium around 1600, whereas the cmcible process was rediscovered in the British Isles in 1740. 

Chung GS, Swart PK (1990) The concentrahon of ttranium in freshwater vadose and phreatic cements in a Holocene ooid clay a method of identifying ancient water tables. J Sediment Petrol 60 735-746 Cliff RA, Spotl C (2001) U-Pb dahng of speleothems from the Spannagel Cave, Austria. XI EUG... 

Concretes are cements containing a large proportion of gravel. Hydraulic cements are cements that set (harden) in wet environments, as required when building structures submerged in water. Like all other cements used in ancient times, hydraulic cements were also composite materials in which one particular component, such as pozzolana in ancient Rome (see text below), endowed the cement with the property of setting in wet environments (Gani 1997 Akroyd 1962). 

There are various reasons to study the composition of ancients cements. The actual composition of a cement, for example, provides information on its nature, the technology used for making it, and the provenance of its components (Middendorf et al. 2005). It may also elicit differences between the nature of an original cement used for building and that used for later repairs (Streicher 1991 Jedrzejewska 1990). Most analytical work concerning ancient cement in the recent past has been based mainly on the use of optical microscopy and classical analysis techniques. Sometimes, such studies are complemented with information derived by instrumental techniques (Blauer-Bohm and Jagers 1997). 

Jedrzejewska, H. (1990), Ancient mortars as criterion in analysis of old architecture, in Mortars, Cements and Grouts Used in the Conservation of Historical Buildings Symp., Rome, pp. 311-329. 

Moropoulou, A., A. Bikulas, and S. Anagnostopoulou (2005), Composite materials in ancient structures, Cement Concrete Compos. 27, 295-300. 

Nonhydraulic cements were among the most common of the ancient cements. The relatively high solubilities of portlandite (Ca[OH]2) and gypsum means that they deteriorate rapidly in moist or wet environments. Many decades ago, the Romans used lime-based cements and mortars (cement plus sand) by ramming the wet pastes... 

Herodotus (484-425 B.C.) mentioned the occurrence of many lumps of bitumen in the River Is, a small tributary of the Euphrates (10). The Babylonians heated this bitumen and used it instead of mortar for cementing together the bricks of their walls and buildings (11). Herodotus also spoke of a well near Susa (the Shushan of the Bible) which yielded bitumen, salt, and oil (11). Cornelius Tacitus, a friend of Pliny the Younger, described the bitumen of the Dead Sea (12). R. J. Forbes states in his book Bitumen and Petroleum in Antiquity that the ancients used tar and pitch for waterproofing pottery, for caulking ships, and for making torches, paint for roofs and walls, and lampblack for paints and ink (13). 

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