IAEG2006 Paper number 80 © The Geological Society of London 2006 1 Determination of the durability of some Egyptian monument stones

Abstract: The parade of historical monuments preserved in and around Cairo span a period of more than five thousand years and documents the entire civilization of the country. There is no one epoch of history, which has not left its numerous traces. However, stone damage or deterioration of monuments in Cairo due to weathering is a growing concern. Therefore preservation and remedial measures have become very important. A comprehensive survey of stone deterioration in general needs a range of studies including destructive testing of sample cores. However, the degree of weathering can also be determined non-destructively, using image processing based on recording surface color changes in the rocks, which are the first observed feature of deterioration. Image processing is a very recently developed technique being used to analyze digital photographs in order to predict the impact of weathering on stone monuments. In the present work, this technique has been adapted to investigate eight sites of Islamic monuments in Cairo. The “RGB ” color system was used and a computer analysis of digital images taken of the monuments, as well as of the source stones used, was carried out. 330 cross-sections were taken from the photos of studied stones. By this method it was possible to carry out a detailed analysis of the deterioration of the monument stones. Using this image analysis, it was possible to predict quantitatively the degree of repair needed for the deteriorated monument without touching the stone, taking core sample or using destructive testing methods