No abstract

This study concerns the investigation of mortar layers and pigments of wall paintings from the Roman town of Emona (Ljubljana, Slovenia). Fragments of wall paintings consist of up to three preserved mortar layers. The mineralogical–petrographic compositions of the mortars were determined by means of optical microscopy and FT–IR spectroscopy. The investigated samples were divided into several groups based on similar thicknesses of the mortar layer, the binder colour and the composition of an aggregate. Furthermore, the results of mercury intrusion porosimetry showed that mortar layers consisting of carbonate grains exhibited lower porosity with respect to layers with mainly silicate grains, which is attributed to the angular shapes of carbonate aggregate. This is in accordance with the drilling resistance measurement system test (DRMS), confirming that layers with angular carbonate grains are harder than those with addition of rounded silicate ones, due to the good packing effect. The wall paintings were mainly executed using the fresco technique, while for some details secco was used. The identified pigments were red and yellow ochre, green earth, Egyptian blue, carbon black and lime white; all of them belonged to the so‐called austere pigment, which is quite common in Roman wall paintings.

No abstract

Archaeological excavations of Roman Celeia (present-day Celje, Slovenia) carried out about 30 years ago revealed the remains of a Roman residential building where more than 9000 fragments of wall paintings were found. The past manual reassembling of fragments proved to be time consuming, limiting the amount of the material that can be examined and reconstructed. However, recently work has been resumed using a software application specifically developed for fragment reassembly. Information on mortar types can provide additional data about the fragments and thus help in the reconstruction process. Fragments of the wall paintings consist of up to three preserved mortar layers, differing in their thicknesses, aggregate compositions and binder colours. Based on the mineralogical/petrographic analyses of the mortars, the investigated fragments of the wall paintings were divided into several groups. The results revealed that the first-mortar-layer aggregates of all the fragments consist of carbonate grains, while the other-mortar-layer aggregates consist of carbonate, silicate/carbonate, silicate or silicate/ceramic grains. Keywords: wall paintings, Roman mortars, petrography, reassembling, fragments Arheolo{ka izkopavanja rimske Celeie (dana{nje Celje) pred pribli`no 30 leti so razkrila ostanke anti~nega stanovanjskega objekta, v katerem je bilo najdenih ve~kot 9000 fragmentov stenskih poslikav. Sestavljanje tak{nega {tevila fragmentov zahteva veliko~asa. Nedavno je bila za sestavljanje fragmentov razvita posebna ra~unalni{ka aplikacija. Informacije o sestavi malte se uporabljajo kot dodatni podatki pri sestavljanju fragmentov. Fragmente stenskih poslikav sestavljajo do tri ohranjene plasti ometov, ki se razlikujejo po debelini, sestavi agregata in barvi veziva. Analizirani fragmenti so bili na podlagi mineralo{ko-petrografskih preiskav razdeljeni v ve~skupin. Rezultati so pokazali, da pri vseh fragmentih zgornjo plast ometa sestavlja agregat iz karbonatnih zrn, medtem ko agregat spodnjih plasti sestavljajo bodisi karbonatna, silikatna/karbonatna, silikatna ali silikatna/kerami~na zrna.