Orlando Favoni

Black crusts on ancient mortars

Samples of mortar damage layers found on ancient masonry have been analysed. The paper presents the characterisation of the black crusts, which are the accumulation areas of material damage and atmospheric deposition, and includes a complete identification of the sulphur, nitrogen and carbon compounds. The presence of anthropic aerosol and its role in the process of damage is evidenced.

Innovative consolidating products for stone materials: field exposure tests as a valid approach for assessing durability

The impact of climate on cultural heritage surfaces leads to several damage processes and the protection and the preservation of works of art is a challenge for conservation scientists and restorers. Traditional and innovative products are used in consolidating treatments in order to reduce the effects of the interaction environment-materials. The EC NANOMATCH Project aims at the development of innovative consolidating agents for carbonate matrices, wood and glass whose features should result in high compatibility, efficiency and long-lasting effect. In this project, metal alkoxides, molecular precursors for the deposition of metal carbonate are synthesized, characterized, tested and proposed as an alternative to traditional consolidating agents as well as to calcium hydroxide nanoparticles. This paper gives an overall description of the methodological approach adopted for the in field evaluation of durability taking into account the environmental impact. Preliminary results of the analyses carried out on carbonate stones aimed at investigating the features of the consolidating treatment are here presented and discussed.

Evaluation of atmospheric deposition on historic buildings by combined thermal analysis and combustion techniques

Abstract Black crusts collected from monuments and historic buildings were analyzed. The analytical methodology adopted involved a preliminary characterization of the samples by means of X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM-EDAX). The anions present were quantified using ion chromatography (IC). Differential thermal analysis (DTA) and thermogravimetric analysis (TGA), combined with combustion techniques, allowed the quantification of the products of degradation and atmospheric deposition. In addition, the carbon of atmospheric origin was identified and quantified in its carbonate, non-carbonate, elemental and organic fractions.

Characterization of hydraulic mortars from archaeological complexes in Petra

In the sixth century BC Petra was conquered by the Nabataeans, who built an elaborated water system and turned a desert city into an artificial oasis and a prosperous centre controlling the main commercial routes of the region (100 BC - 100 AD). In 2007, it was added to UNESCO’s prestigious list of World Heritage Sites, as one of the seven wonders of the world. The aim of this research is to characterize samples of mortars lining cisterns, reservoirs and pipelines collected from the archeological site of Petra, focusing in general on the identification of the possible raw materials employed and in particular on those components conferring hydraulicity. Specifically the specimens were sampled from different structures of the Great Temple (cistern and pipelines) and of the Garden and Pool Complex (cisterns and reservoir floor). A petro-mineralogical characterization was carried out by polarized light microscopy (PLM) observations to identify the texture and to highlight the hydraulic reaction areas, which underwent subsequently to a more detailed morphological and elemental analysis by scanning electron microscopy (SEM-EDX). X-Ray Diffraction analyses (XRD) were also performed to complete the petrographic characterization, while thermal analyses (DTA-TGA) were carried out to classify the level of hydraulicity of each sample. The data obtained allowed us to achieve for the first time a mineralogical and petrographic characterization of the lining hydraulic mortars present in the two archaeological complexes under study and to provide preliminary hypotheses on the provenance of the raw materials employed for their production.