Diagnosis of construction stone type as a step of the conservation plan for Cairo citadel aqueduct

Document Type : Original Article


1 Conservation Dept. Faculty of Archaeology, Cairo University

2 postgraduate student, Conservation Dept. Faculty of Archeology, Cairo University, chemical researcher at the Radio Engineering Research Center in El Haram.

3 Refractories, Ceramics and Building Materials Department, Advanced Material Technology & Mineral Resources Research Institute, National Research Centre (NRC), El Bohouth St., Dokki, 12622 Cairo, Egypt.


The aqueduct of the Cairo Citadel is one of the significant Ayyubid structures in Cairo, which dates back to 914 AH - 1508 AD, it was built for the purpose of transporting the Nile water to the mountain citadel with a length of 2.2 km., Unfortunately, the aqueduct of the Cairo Citadel is exposed to damage and extinction for many natural and human reasons. As a first stage in the restoration process, it is necessary to assess the existing state and make the proper diagnosis of this significant monument, it is necessary to identify the type and condition of the building stones used in the construction process and to achieve this goal some stone samples were collected for testing of physical and mechanical properties, using polarizing microscope (PLM), scanning electron microscope coupled with Energy dispersive X-Ray unit (SEM-EDX), X-ray diffraction (XRD), and X-ray fluorescence (XRF).

The study showed that the type of stone used for construction is fossiliferous limestone (Biomicrite) very fine to fine-grained. Micro-fossils and fossil fragments are present in significant amount scattered in the very fine-grained matrix, a tiny amount of clay mineral are present. The stone samples show 11.68% water absorption, 2.02 g/cm3 Bulk density 23.62% apparent porosity and 9.65 MPa compressive strength. Stone samples suffers from black hard crust, micro-cracks, crystallization of salts, in addition to microbial infection with Halophilic fungi growth. Based on the present study results and studying the surrounding environmental conditions, an appropriate restoration plan can be developed.


Main Subjects

Volume 65, Issue 13 - Serial Number 13
Special Issue: Chemistry and Global Challenges
December 2022
  • Receive Date: 01 July 2022
  • Revise Date: 27 August 2022
  • Accept Date: 28 August 2022
  • First Publish Date: 28 August 2022