LASER INDUCED BREAKDOWN SPECTROSCOPY AND OTHER ANALYTICAL TECHNIQUES APPLIED ON CONSTRUCTION MATERIALS AT KOM EL-DIKKA, ALEXANDRIA, EGYPT

Abstract

In order to retrofit and conserve the archeological site of Kom El-Dikka, Alexandria, Egypt, a systematic study of construction materials was applied. The samples of mortars, brick and limestone samples have been taken from the remains of ancient Auditorium, houses and baths (300 AD). The analytical techniques showed that different qualities of mortars and brick were used for different purposes. Almost impermeable hydraulic mortars were found in contact with draining canals. This was the initiative to start combining advanced analyses of mortars and other construction materials by determining their physical and chemical characteristics in order to find the textural features and the alterations of the structure and understand their resistance to weathering.

Here samples were analyzed and examined by using Laser induced breakdown spectroscopy (LIBS), SEM attached with EDX, Polarizing microscope, Optical microscopy in transmitted polarized light, XRD, DTA-TGA, Grain Size Distribution, Pore Media Characterization, while some limestone and mortars were tested, to determine their uniaxial compressive strength, porosity, water absorption, proportion of constituents of cement mortars, and durability.

The paper focuses on the interrelation of findings from the above-referred examinations. The use of reactive siliceous materials in combination with lime, as well as, the excellent gradation of aggregates used seems to be the ancient protocol of the good performance of the ancient mortars. It is concluded the high skillfulness of ancient masons of the classical period in construction materials.