Mortars in context: An integrated study of mortars and plasters from the so-called Ginnasio in Solunto (Sicily, Italy)

This paper presents a multipronged scientific study of mortars and plasters of the so-called Ginnasio in the Hellenistic–Roman city of Solunto (Sicily, Italy). A selection of 16 well-contextualized samples was collected to represent different functions and building phases of this private house. The results show that a variety of locally available raw materials was used as aggregates and to produce binders. The diversity of raw materials’ sources and production techniques identified in this study reveals the advanced technological knowledge of the builders of Solunto, indicating a complex relationship between the settlement's cityscape and its surrounding landscape

The Mortars of Florence Riverbanks: Raw Materials and Technologies of Lungarni Historical Masonry

The study of structural masonry joined to geohydrological hazards in cultural heritage represents a multidisciplinary theme, which requires consideration of several aspects, among them the characterization of the materials used. In this paper, a first complete chemical, minero-petrographic, and physico-mechanical characterization of core samples taken from the masonry of two Florence riverbanks (Lungarno degli Acciaiuoli and Lungarno delle Grazie) is performed in order to identify the raw materials, technologies, and state of conservation and to support the planning of maintenance and restoration interventions. The physico-mechanical characterization of the riverbanks allows their stability to be determined. Such investigations allow identification of the level of compactness and cohesion of masonry; this information is useful for planning emergency interventions and for supporting planned restoration activities. The results provide valid support for the design of riverbank safety projects, to mitigate the risk of their collapse and to decrease the flood risk in the historic center of Florence

Characterization protocol of Florentine historical mortars for absolute dating

The raw materials used in the realization of a mortar provide information on the supply areas, original recipes and ancient technologies used to realize a building or an artefact. The raw materials utilized may vary over time, so they may be useful to give an indication of its relative dating. In this field, from the pioneering studies of Labeyrie and Delibrias, (1964) and Stuiver and Smith, (1965), was evaluated the possibilities to radiocarbon dating of historical mortars; this research field still open, since may present many issues in its application. In principle, the carbon fraction datable is represented by calcite (CaCO3) resulting from the hardening of the quicklime (calcium hydroxide, Ca(OH)2) that reacts with CO2 from the atmosphere. The lime binder and lump (un-mixed portion of lime in an aerial mortar) represent the portions that must be isolated from other carbon sources to accurately date mortars. Previous research shows that suitable and proper sampling of mortar samples is of fundamental importance for a conclusive radiocarbon analysis. In recent years, a complete characterization of the mortar before radiocarbon dating was strongly encouraged (Cantisani et al. 2021). The minero-petrographic characterization is the first step to identify the type of mortar and to develop an efficient analytical approach that allows to select the most suitable component of mortar for absolute dating. This work is aimed at mortar characterizing of an important architectural Cultural Heritage in Florence (Italy), Palazzo Medici Riccardi, to understand the building technique, the choice of raw materials, the history of its construction and, possibly, the presence of mortar datable fraction. A correct sampling and characterization procedures allow to know the composition of the binder, the nature of the aggregate, the presence of lumps, the carbonate origins etc. Therefore, to reduce the cost and time of dating, it is necessary to utilize always a fully characterized sample, consisting of a calcite binder, to be subjected subsequently to analysis to accelerator mass spectrometry (AMS) for dating. The research proposes on operative protocol applied on 12 mortar masonry samples of Palazzo Medici Riccardi, composed by: i) a preliminary in-depth characterization of mortar specimens, by means of multi-analytical techniques such as OM, XRPD, TGA, SEM-EDS, OM-CL for a chemical, minero-petrographic and physical characterization fields; ii) non-destructive analyses of datable samples selected, using XRPD, OM-CL and ATR-FTIR (Calandra et al. 2022). The combined use of characterization techniques is the key to obtaining more evidence regarding the composition of the samples to be dated. The selection protocol has made it possible to choose several samples for dating, thanks to which the history of the construction of Palazzo Medici Riccardi will be further explored

Stones for the production of binding materials in Florence area (Tuscany, italy)

From the Roman times to nowadays the exploitation of natural resources has been of primary importance for the expansion and developments of cities and population in general. As long as for more precious natural materials, like gold and silver, even the exploitation of limestones and other lithotypes of stones for building purposes, as the production of quicklime, hydraulic lime and cements, has covered and still has a great importance (Cantisani et al., 2018; Fratini et al. 1994). The limestone exploitation to produce mortar and concrete in the territories of Florence and Prato has been active in the area from the Roman times (Cantini et al., 2017; Raneri et al., 2018). The main goal of this paper is to characterize the different lithotypes useful to the production of cement and limes for mortar production in this area by mean of chemical, mineralogical and petrographic studies and by defining their physical and mechanical properties. This study analyses stone samples from different quarries, one from the province of Prato, Mt. Calvana, and two quarries from the province of Florence, Settimello and Greve in Chianti. A mapping of these quarries and a comparison between the chemical, mineralogical and petrographic characteristics and physical and mechanical properties of these lithotypes are made