This study deals with the characterization of mortars collected from baths of the Roman villa rustica from an archaeological site near Mošnje (Slovenia). The mortar layers of the mosaics, wall paintings and mortar floors were investigated. In the studied mortars, a special additive, consisting of fragments of crushed burnt clay, is present. The mineralogical and petrographic composition of the mortars was determined by means of optical microscopy, XRD analysis and FTIR spectroscopy. Analysis of aggregatebinder interfaces using SEM-EDS revealed various types of reactivity rims. In order to assess the hydraulic character of the mortars, the acidsoluble fraction of the mortars was determined by ICP-OES. Furthermore, the results of Hg-porosimetry and gas sorption isotherms showed that mortars with a higher content of crushed burnt clay particles exhibited a higher porosity and a higher BET surface area, but a lower average pore diameter compared to mortars lacking this special additive.
F.27 Contribution to preserving/protecting natural and cultural heritage
COBISS.SI-ID: 917342The black limestone from Drenov Grič quarry (Central Slovenia) is considered one of the most beautiful Slovenian natural stones due to its typical color. The limestone was characterized from mineralogical, chemical, and petrophysical points of view. Furthermore, deterioration phenomena of the limestone from two monuments exposed to indoor and outdoor environments were studied. In situ investigation of two monuments by means of monument mapping has identified several types of deterioration phenomena, such as granular disintegration, flaking, crumbling, efflorescences, crusts, and the presence of microorganisms. Samples were characterized using Optical Microscopy (OM), Scanning Electron Microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), X-Ray Powder Diffraction Analysis (XRD), porosity accessible to water under vacuum, capillary absorption, Hg-porosimetry, and Ar-sorption. Although very low values of porosity of the fresh stone as well as slow capillary kinetics were determined, both monuments showed severe deterioration as a consequence of the transport and precipitation of soluble salts within the stone.
F.27 Contribution to preserving/protecting natural and cultural heritage
COBISS.SI-ID: 950110The black limestone widely used particularly in the baroque architecture of central parts of Slovenia is deteriorating extensively due to salt crystallization. Samples of soluble salts from two important historical monuments (Ljubljana, Slovenia) were investigated with respect to their mineral and isotope (S and O) compositions. Results revealed the presence of gypsum and soluble salts of the MgSO4.nH2O series such as starkeyite (MgSO4.4H2O), pentahydrite (MgSO4.5H2O), and hexahydrite (MgSO4.6H2O). Whereas black crust and subflorescence consisted of gypsum, efflorescence appeared to be an assemblage of gypsum and magnesium sulphate hydrates. The oxygen and sulphur isotopic signature of the samples showed that δ18Osulphate values vary from –1.9 to +5.5‰ vs. VSMOW and δ34Ssulphate values vary from 19.8 to +3.2 ‰ vs. CDT. The isotopic composition of analysed outdoor and indoor monument samples indicates different sources of contamination.
F.27 Contribution to preserving/protecting natural and cultural heritage
COBISS.SI-ID: 893022