The History of Concrete and the Nabataeans

http://nabataea.net/cement.html




Cement mortar and plaster played an important role in Nabataean life. They used this essential technology from their very earliest years in the desert. Without their special knowledge of cement, the Nabataeans would never have conquered the desert, and would never have risen to the status of a civilization.

Other tribes in the deserts of Arabia lived within the limits that nature put on them. They stayed close to sources of water, and ranged their sheep and camels from there. The Nabataeans on the other hand, built water channels and cisterns far out in the desert to collect the scant rainfall and store it for their use.

Without this knowledge of waterproof cement, the Nabataeans would not have become the far ranging merchants of the Middle East, who easily traversed deserts and inhospitable, barren mountains.

How was it that the Nabataeans developed waterproof cement centuries before its use became common in Europe? In this study, we will begin by examining cement in general, and then looking at how cement was developed and used by other civilizations, especially the Romans. The Romans were contemporary to the later part of the Nabataean Empire, and whose historians recorded for us, how the Romans made and used cement. Lastly, we will look at the special properties of Nabataean cement and speculate about how they developed this amazing technology.

Cement in General
Cement and concrete are often thought of as the same thing, however, they are by nature very different. Cement is an ultra-fine gray powder that binds sand and rocks into a mass which is called concrete. Cement is the key ingredient of concrete, but concrete contains other substances like sand and rocks.

Cement has become one of the world's most widely used building materials. Annual global production of concrete hovers around 5 billion cubic yards, a volume approximated by yearly cement production levels of about 1.25 billion tons. Concrete's global appeal is not accidental, for this stone-like material is produced from some of the world's most abundant resources.


It is important to understand the development of cement on a more global basis, in order to see how Nabataean cement relates to the worldwide development of cement technology. Then we can ask the important question, did the Nabataeans learn their technology from others, or did other civilizations learn their technology from the Nabataeans?

The Toughness of Imperial Roman Concrete

http://www.academia.edu/1214963/The_toughness_of_Imperial_Roman_concrete

ABSTRACT: The concrete composites used to realize the monumental structures of Imperial Rome are re-markable engineering materials. While the endurance of intact constructions such as the Pantheon evinces theconcretes’ durability, such durability mostly serves to preserve the mechanical properties, which are responsi- ble both for the monuments’ original creation and continued survival. Despite their prominent role in the en-gineering achievements of the Empire, these mechanical properties – particularly in tension and fracture – have not been comprehensively assessed. We first review the mechanical properties obtained through variousexperimental programs conducted on both authentic Ancient composite core samples and their components,summarizing the major findings and outlining the remaining gaps in knowledge. We then qualitatively discussthe fracture of Roman concrete within the context of our own testing program, which will test both re-fabricated and authentic materials, with the aim of characterizing the fracture behavior that has contributed tothe preservation of a significant component of engineering heritage