Classification and provenance of soapstones and garnet chlorite schist artifacts from Medieval sites of Tuscany (Central Italy): insights into the Tyrrhenian and Adriatic trade

Soapstones (talc-bearing schists) and garnet chlorite schist artifacts found in Medieval archaeological sites of Tuscany (Central Italy) were classified, in order to define provenance of the different lithotypes. In Italy and throughout the Central Europe, these greenschist facies metamorphic rocks are generally known, among the archaeologists, as the pietra ollare from the Alps. The investigated Tuscan archaeological sites are between 6 and 13th century AD and were strictly linked, in that period, to the well defined network trade running along Tyrrhenian coast. Samples come from little containers used for cooking and preserving food and showing traces of lathe manufacturing at their sidewalls. According to modal mineralogy, petrographic texture, XRD, SEM-EDS and whole rock chemistry we recognised, among the 18 studied findings, three different petrographic groups of the Alpine pietra ollare. (i) Fine grained magnesite talc schists (i.e. soapstones) from outcrops of the Central Alps located in the Valchiavenna area. (ii) Garnet chlorite schists from the Valle d'Aosta region. (iii) Amphibole talc schists (i.e. soapstones) with a provenance in the Ticino area. It is worth noting that artifacts of pietra ollare lithotypes from the Western Alps (i.e. garnet chlorite schists and amphibole talc schists) were not detected in the archaeological sites of the Middle Adriatic coast of the Central Italy, belonging to the same Medieval time interval. This emphasises that the petrographic groups of pietra ollare from the Alps spread to the south of the Po Plain according to Western and Eastern trade along the Italian Peninsula, using respectively, the Tyrrhenian and the Adriatic Sea commercial routes.     

Monitoring of Two Great Venetian Cathedrals: San Marco and Santa Maria Gloriosa Dei Frari

Two examples of monitoring systems of great Venetian Cathedrals, are presented. The first, concerning the Basilica of San Marco, is an example of a long-term monitoring system for a structure that has not undergone any strengthening intervention. The criteria for interpreting this monitoring system data are illustrated. The second example, concerning the Basilica of S. Maria Gloriosa dei Frari, is a clear example of the use of monitoring during the execution of strengthening intervention. This study illustrates the interventions that were carried out on the supporting structures: consolidation of the soil foundation of the bell tower by using the soil-fracturing technique and creation of a structural joint between the bell tower and the Basilica. Through the observational method, this monitoring system was able to check the structural behavior during all the phases of the interventions, thus becoming a precious design tool able to guarantee the safety of the structure and to modify the design solutions during the strengthening intervention, according to the real deformation behavior observed through the monitoring system.     

Salt Effects in Plastered and Unplastered Outdoors Brick Masonry: Quantitative Laser Monitoring of Surface Decay Evolution

In masonry materials, the superficial decay is a widespread problem. Aggressive environmental agents such as moisture and salts trigger the damage by propagating through the material capillary pores. Although several studies have been carried out on salt crystallization and their damaging effects, additional research effort is required to better investigate this phenomenon on real cases and real weathering conditions. To this purpose, testing and monitoring tools capable of following degradation process since the early beginning are necessary. Repeated visual inspections are commonly used to monitor the superficial decay, but this technique is subjective and thus not capable of providing any quantitative information. In this work, an experimental campaign, carried out in Bologna, Italy, is presented. A two-header brick wall, one main face unplastered and one plastered, was stored outdoors and exposed to weathering over two summers. Before the start of the second aging season, moisture and salt capillary rise was simulated by low-concentrated sodium chloride solution (0.1% -wt). The aim was to favor solution evaporation and salt crystallization and to provoke material damage. The degradation process was monitored based on a contactless, rapid and accurate image diagnostic technique. In particular, high-resolution laser scanning by triangulation technique was adopted. Three-dimensional data acquisition was repeated at the end of both seasons. The proposed procedure successfully extracted quantitative information approximately areas of material spalling and detachment even in the initial phases of decay.     

Mediterranean trade of the most widespread Roman volcanic millstones from Italy and petrochemical markers of their raw materials

The petrochemical study of millstones can contribute to improve the archaeological research into reconstruction of ancient communication routes and trade networks. Volcanic rocks are geographically restricted and rather rare in the Mediterranean regions, and during the Roman period Italian volcanoes were important sources of raw materials for millstones, so the task of determining their geological origin is relatively straightforward. The Italian vesicular volcanics most frequently employed for this purpose were: trachytes from Euganean Hills (Veneto), leucite-bearing lavas from the Vulsini Volcanic District (Latium), basic-intermediate leucite-bearing lavas from Somma-Vesuvius (Campania), silica undersaturated lavas from Monte Vulture Volcano (Basilicata), a rhyolitic ignimbrite from Sardinia and basic products from Mount Etna and the island of Pantelleria (Sicily). This paper contains a general outline of the trade network for each volcanic typology used for millstones during the Roman period – updated with data concerning the leucite-bearing lavic items discovered in the archaeological sites of the ancient Cuicul (now Djemila, Algeria) – together with a summary of their petrographic and geochemical features.     

Euganean trachytic grinding stones in the Caput Adriae from the Iron Age to the Roman period: Reassessment of the Protohistoric quarries

A group of Euganean trachytic grinding stones from Slovenia and the available data about the same type of artefacts in the whole Caput Adriae are presented. The occurrence of Iron Age saddle querns in Karst and Istria is confirmed, but our study suggests a likely provenance from Mts Cero/Murale instead of Mts Altore/Rocca Pendice, as previously suggested. Este, an important Venetic centre, is just south of Mts Cero/Murale, suggesting its central role in the production and distribution of saddle querns. During the Roman period Euganean trachytes are still used for rotary millstones, but new quarries (Mt Rosso), relatively close to ancient Padua, are exploited. Such shift in the position of millstone quarries most probably reflects the changed geopolitical framework.     

Modeling and Seismic Response Analysis of Italian Code-Conforming Reinforced Concrete Buildings

ABSTRACT

This study investigates the seismic response of reinforced concrete buildings designed according to the current Italian building code. Number of stories, site hazard, presence and distribution of masonry infill panels, and type of lateral resisting system are the key investigated parameters. The main issues related to design and modeling are discussed. Two Limit States are considered, namely Global Collapse and Usability-Preventing Damage. The main aim of the study is a comparison between the seismic response of the buildings, investigated through nonlinear static and dynamic analyses. Irregularity in the distribution of infill panels and site hazard emerge as the most influential parameters.