Ancient cements, study

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). 

Sandstones with little clay cement are a favourable environment for the circulation of silica-bearing deep waters, especially in provinces with a network of faults (Taylor 1950 Heald 1956). In these conditions some silica could precipitate in the available pore space. In the study area, it was particularly important to examine closely ancient faulting, i.e. Triassic and Cretaceous communicating faults which do not seal between different reservoir blocks. However, studies of the relationship between sandstone permeability and the distance of boreholes from fractures and faults have demonstrated that the mean permeability of sandstones from boreholes located within 500 m from faults is practically the same as the mean permeability of sandstones from other boreholes. 

Since mercury porosimetry has been used to a considerable extent in the study of hardened Portland cement, it seemed appropriate to apply it in the assessment of porosity of Ancient Egyptian Mortars. X-ray diffraction and simultaneous thermograviraetry and differential thermal analysis were used as additional techniques in the present study. 

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