Monitoring coptic masonry affected by clay minerals and microorganisms at the church of virgin mary, wadi el-natrun (Egypt)

Abstract

This paper focuses on the role played by the clay minerals and microorganisms in the deterioration process of Coptic architecture units at the church of Virgin Mary, Wadi El-Natrun region. For this purpose building materials (mainly mortars and plasters) from the studied church were examined using X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscope with energy dispersive spectroscopy (SEM-EDS); in order to identify their composition and were investigated petro-graphically to determine the real response of the masonry structure to the deformation imposed at the endogenous factors. Wall gypsum mortars in the church contain halloysite as a dominant clay mineral while plaster is clay free; concerning microorganisms, the fungal flora Aspergillus glaucus represent the most dominant fungi constituting (22.22%), Aspergillus flavus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus occhraceus, and Aspergillus caudidus were also isolated.