Archaeological monuments of Saqqara region are affected by
cracking, weathering and man-made actions that have resulted in
different types of deterioration in the long run. Accordingly historical
masonry tombs in Saqqara require a full characterization of the
materials used for their construction, before any restoration processes. The assessment of the mechanical and physical characteristics
of the building materials is based on visual observation, sampling
of the building materials used and laboratory testing of the samples
(bulk density, porosity, water absorption, optical microscope, polarizing microscope (PM), XRD, SEM, compressive strength, …etc.).
The present study is concerned with the restoration and reconstruction of a masonry tomb in Saqqara (Tomb of Queen Khenut),
which over the years suffered significant damage due to various
deterioration actions. Limestone used in the construction of historical
buildings in Saqqara is classified as carbonates and salts with
carbonate fragments stone. The stone is composed of carbonate
cuttings; each of them is broclastic limemud stone to weak stone.
This structure generally presents heterogeneous granular texture;
with a very rare matrix and low cementation level between the internal
components, causing a fair development of intergranular porosity.
The values of bulk density are ranging from 2.22 to 2.33 gm/cm3.
Otherwise, the results of porosity reveal remarkable differences
between the different samples. Also the stone has low compressive
strength values (The uniaxial compressive strength values varied
from 96 to 104 Kg/cm2), due to the defects in its internal structure
and decaying products. Finally, a damage description was carried
out to identify the decaying forms. It is the basis for the quantitative
rating of limestone damage by means of damage forms and products.
Limestone in Queen Khenut's Tomb exhibits the need for restoration
and preservation procedures.