Comparative analyses of Roman mortars belonging to different ancient periods from Drobeta-Turnu Severin region

The main object of investigations in this work is the study of the various Roman mortars in Drobeta-Turnu Severin, Romania; the results help clarify the technology used for the construction of the studied sites through different thermoanalytical techniques. The first site encompasses the surviving elements of the Danube Bridge built by the Romans at the beginning of the second century AD to help in their conquest of Dacia. The aim is to establish the extent of similarity or difference between the studied samples. Thermal analysis and infrared spectroscopy are used in the study of different mortar samples. This paper highlights the compatibility of the techniques used: XRD for identifying major crystalline phases, FTIR for a more detailed image for the noncrystalline phase composition and TGA for a quantitative determination of volatile phases (especially CO2 and H2O). The analyses carried out on the mortar samples managed to divide the samples into different categories, obtaining very good correlations between the techniques used. The results also indicate that mortar samples from both the bridge and the Roman Castrum are within known values for Roman mortars.