Durability problems of the archaeological construction materials in aqueous and subaerial environments, with applications for restoration and conservation in Egypt and Sudan

Abstract

The main objective of the study was to identify and assess the conservation problems of the building materials of each case study and compare the aggressive impacts of each environment on the sustainability of the construction materials. Carefully, the construction materials (limestone, sandy limestone, sandstone, lime mortars, gypsum, hydraulic lime mortar/roman mortar) were selected from different archaeological sites with different environmental conditions in Egypt and Sudan (desert: Sahure?s pyramid and pyramids of Meroe; urban/agricultural: Nero/Ramses II Temple; coastal: Anfushi?s Necropolis; and fluvial: Abaton/Osiris Temple). To achieve this goal, field observations, analytical (X-ray diffraction, X-ray fluorescence, Raman spectroscopy, UV-Vis spectrometry), microscopic (binocular microscope, polarizing microscope and scanning electron microscope), mapping (AutoCAD, ArcMap 10.8, SeaDAS, QGIS), and physical and mechanical testing investigations were carried out. Furthermore, open-access satellite lenses were used for the detection and assessment of the archaeological sites and their risks, and, the deterioration patterns of each case study were recorded through decay mappings. Finally, to preserve the lime mortar surfaces, a newly synthesized nanomaterial of SiO2-TiO2 NPs/TEOS was applied and tested. The results showed the severity of each factor on the construction materials. In this sense, Sahure?s pyramid was affected mainly by climatic and environmental factors, earthquakes and the inner composition of the building materials. Nero/Ramses II Temple showed its susceptivity mainly from the salt attack which came from the contaminated sources of water around the temple. Water intrusion, earthquakes, storms, and heavy rains factors attacked Anfushi?s Necropolis severely. Abaton/Osiris Temple was decayed because of Nile water fluctuations impact and the inner weakness of the temple sandstones. In Sudan, the pyramids of Meroe were damaged because of the sand dunes and wind forces, in addition to the flooding risks. Finally, and concerning to the heritage conservation, the research exhibited the efficacy of the multifunctional 3% and 5% SiO2-TiO2 NPs/TEOS in the consolidation and improvement of the physical and mechanical ancient lime mortars.