Samples of mortars were collected from lime and hydraulic mortars affected by environmental, mainly water induced degradation. Moisture and humidity possesses a main threat for the preservation of historic monuments. Agents of decay related with water such as acid rain, sulfate attack, acid attack, leaching action, salts attack, damage due to frost and many more can cause extensive cracks and total disintegration of historic constructions. 50 samples were obtained from historic constructions located in North Greece. Isotopic data will make possible to provide weathering gradients. The samples were characterized in terms of their isotopic, chemical and mineralogical composition. Compositional and morphological analyses were achieved using energy dispersive X-ray analysis in the scanning electron microscope. The results of micro-morphological and petrographic examination elucidate the different sources of degradation of historic mortars. Stable isotope analysis (C-13 and O-18) provided information relative to the origin of CO2 and water making possible to distinguish different sources of water induced degradation. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of water -induced degradation and to determine the weathering depth and the potential secondary degradation mechanisms.

Samples of mortars were collected from lime and hydraulic mortars affected by environmental, mainly water induced degradation. Moisture and humidity possesses a main threat for the preservation of historic monuments. Agents of decay related with water such as acid rain, sulfate attack, acid attack, leaching action, salts attack, damage due to frost and many more can cause extensive cracks and total disintegration of historic constructions. 50 samples were obtained from historic constructions located in North Greece. Isotopic data will make possible to provide weathering gradients. The samples were characterized in terms of their isotopic, chemical and mineralogical composition. Compositional and morphological analyses were achieved using energy dispersive X-ray analysis in the scanning electron microscope. The results of micro-morphological and petrographic examination elucidate the different sources of degradation of historic mortars. Stable isotope analysis (13C and 18O) provided information relative to the origin of CO2 and water making possible to distinguish different sources of water-induced degradation. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of water –induced degradation and to determine the weathering depth and the potential secondary degradation mechanisms.

Bulk samples of mortars were collected from archaeological sites dated from Hellenistic to Roman period in order to investigate the technological evolution of historic structures from simple lime based systems to advanced hydraulic materials. Roman opus caementicium enabled the construction of vaults with a mechanical behaviour of an inert monolith; the rapidly hardened mortar with its concrete-like strength provided a monolithic effect on lighter vaulted structures. The samples were characterized in terms of their isotopic, chemical and mineralogical composition. Stable isotope analysis (13C and 18O) provided information relative to the origin of CO2 and water during calcite formation making possible to distinguish different mortar technologies. The results of micro-morphological and petrographic examination elucidate the technological continuity of historic mortars. Hellenistic mortars are composed of lime enhanced with quartz aggregates. Roman mortars are composed of lime, pozzolan and various aggregates such as quartz, feldspar, ceramic and rock fragments. The isotopic values comprise a range of δ13C and δ18Ο values from −17.6‰ to 3.6‰ and −25.9‰ to 0.4‰ very different from that of local limestones used for mortar production. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of carbonate and therefore indicate the variations in mortar’s technology.

Salts crystallizing in the pore space of building stones cause stone monument degradation. The origin of these salts can be variable: marine, air pollution, together with marine aerosols, building or restoration material. Previous studies using sulfur and nitrogen isotopes demonstrated the important role of atmospheric sulfur and nitrogen to black crust formation and determining it as a principal component of salt weathering of stone monuments. In this study we present isotopic measurements of black crusts from monuments located in North Greece and Attica. The applied methodology is capable to distinguish the sources of the sulfate salts (atmospheric pollution, marine aerosols, bio-pollution).