An experimental study on consolidated sandstone by accelerated salt crystallization cycles: A case study of Dendera Temple, Qena, Egypt

The purpose of this study is to look at the behavior of sandstone used in the Dendera temple’s construction under the effects of weathering and salt crystallization. To achieve our objective, (40) cycles of salt crystallization testing were performed on the selected sandstone samples consolidated by Paraloid B-72 enhanced with (Ca(OH)2 – SO2) nanoparticles using sodium sulfate (Na2SO4) and sodium chloride (Nacl) solutions. Sandstone specimens were subjected to physical and mechanical properties tests, as well as Polarized Light Microscopy (PLM), Scanning electron microscopy (SEM) coupled with X-ray energy dispersive system (EDS) examination, Transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis, this procedure was repeated four times after 10, 20, 30, and 40 cycles. Results of the study indicated that saline solutions containing Na2SO4 cause more damage to sandstone used in Dendera temple, The salt weathering test conducted on sandstone specimens consolidated with paraloid B-72 enhanced with nano-silica have shown superior results compared to other Nano-materials. The study concluded that Paraloid B-72 enhanced with Nano silica achieved the mean weight of 154.5 g, an increase of 7.4% over the untreated specimens, average density of 2.75 gr/cm3, an increase of 7.2% over the untreated specimens, average Porosity of 9.85 % decrease of 27.03% over the untreated specimens and the mean compressive strength of 24.7 MPa an increase of 9.3 MPa over the untreated specimens, it also achieved resistance to salt weathering, indicating that this compound was well suited to the condition of the sandstone used in the Dendera Temple.