Petrological Study on the Roman Mortars from Kom El-Dikka Archaeological Site (Alexandria, Egypt)

Two types of Roman mortars were collected from the buildings of the Thermal Baths, Villa of birds and Cisterns located at Kom el-Dikka archaeological site (Alexandria, Egypt). It is believed that these mortars date back to the first or second century A.D. Petrographical, and chemical characterization of these mortars were performed, to differentiate the various construction phases of Kom el-Dikka archaeological site. Results showed that the analysed samples are lime mortars, with different types of aggregates. The samples from the Cisterns, which showed a high superficial strength, also have a different isotopic ratio (δ13C and δ18O) than the rest of the studied mortar samples. The analysis of soluble salts in the mortar samples was conducted. It reveals a main content on sulfates, nitrates and chlorides, of which provenance probably accounts for atmospheric pollution and marine aerosol, as well as possibly, previous restoration interventions.