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The Valley of the Kings (KV) is a UNESCO world heritage site with more than thirty tombs that have been opened. Since the first tombs were constructed, at least 24 historical flash flood events have been identified, each of which has contributed to the destruction and deterioration of the tombs. After the floods of 1994, most of these tombs were inundated and damaged. Theban Tomb 109, or TT 109, is an example of one of these significant tombs. This study presents a novel technique which uses computer X-ray tomography (CT scan) as a non-destructive method to capture the morphology of the limestone's internal structure at Tomb 109 (TT 109), as well as the stone's grain texture and the surface features through 3D images and videos. Additionally, this research examines the ability of a nanomixture, consisting of tetraethoxysilane (TEOS) and nanosilica, to consolidate the limestone, which is also a novel approach that this study introduces. It is worth noting that the limestone of Tomb 109 has suffered harsh weather conditions such as groundwater and has been in an unfavourable burial environment, causing geostatic stress which in turn has led to stone abrasion and weakness in its mechanical properties. This study also presents a comprehensive morphological and spectroscopic study to confirm the efficiency of the nanomixture in the consolidation of the limestone structures. A cross-examination method using CT scanning, SEM, and XRF analysis before and after consolidation was employed. The final result shows that the nanomixture significantly enhanced the physical and mechanical properties of the limestone., Conservation Science in Cultural Heritage, Vol. 22 (2022)

The current paper investigates the influence of fire on historic stone masonry structures, for the purpose to assess stones structures deterioration, based on non-destructive measurements for significant changes in the physical properties and mineralogical composition of limestone. Different cubic samples of limestone used in historic buildings، were selected and subjected to increasing temperatures, from room temperature to heating at 200°C, 400°C, 600°C, 800°C in the oven for a period of 6 hours. The induced changes in the microstructure, petrophysical and mechanical properties of the limestone were examined and correlated with The petrographic analyses (polarizing microscope, XRD, SEM) and physical parameters (density, porosity, water absorption), mechanical properties (uniaxial compressive strength). Results showed that fires and high temperatures cause significant changes in the physical properties and mineralogical composition of limestone، particularly at temperatures beyond 300oC, produces considerable microcracking and causes colour changes in limestone. The developed cracks act to increase the porosity and significant reduction in compressive strength in limestone. The study included the methods of treatment through for the use of some consolidation materials (Paraloid B72) mixed with nanocomposites in the process of consolidation. Results showed demonstrated the superiority of the Paraloid B72 mixed with Nano calcium hydroxide in the consolidation and filling the spaces between the mineralogical composition for building stones. The results of this paper indicate that the deterioration of limestone depends on mineralogical composition and fabric. The consideration of mineralogical composition and rock fabric parameters, however, helps provide a more comprehensive evaluation and interpretation limestone damage.

The Greek-Roman rock-cut tombs at Alexandria, Egypt, were excavated mainly in the calcarenitic limestone formations and show varying degrees of damage of rock pillars and ceilings. In order to understand the long-term rock mass behaviour in selected tombs and its impact on past failures and current stability, uniaxial and triaxial Creep tests and rock mass quality assessments had been carried out. Creep behavior of rock plays an important role in underground works, especially for archeological structures subjected to large initial stresses. These conditions yield nonreversible deviatoric creep strains that develop during time at constant stress. In order to describe the time-dependent deformation, various approaches have been established based on analytical, empirical, and numerical methods. Our analyses show that the Roman tombs at Alexandria have been cut into poor quality rock masses. Rock failures of ceilings and pillars were frequently facilitated by local, unfavourably oriented persistent discontinuities, such as tension cracks and joints. Other failures were related to the disintegration of calcarenitic and oolitic limestones. Our data suggest that, in Roman age monumental tomb construction, low-strength rock masses resulted in modifications of the planned tomb design in order to minimise the risk of rock falls and to prevent collapses.