Moisture Damage in Ancient Masonry: A Multidisciplinary Approach for In Situ Diagnostics

San Nicola in Carcere, one of the minor basilicas in the historical center of Rome, was the location of a wide investigation campaign of the water-related deterioration causes, present in the lower sector of the apse and adjacent pillars, affected by water infiltrations, mould and salt efflorescence. The results obtained identify the presence of water content and related effects mainly on the sides of the apsidal wall. This work focuses on the use of five Non-Destructive Techniques (NDT) and intends to show the gains obtained by integrating widely interdisciplinary methods, namely the Infrared Thermography (IRT), the Unilateral Nuclear Magnetic Resonance (Unilateral NMR), the Acoustic Tomography (AT), the Acoustic Imaging (AI) and the Laser-Induced Fluorescence (LIF). All the techniques contribute to the rapid, non-invasive and early identification of the moisture distribution, while some of them (LIF and AI) also address the determination of some moisture effects. The integrated use of different techniques helps to take the multidisciplinary point of view necessary to formulate an effective restoration intervention based on a sound scientific rationale; nonetheless, it allows to experiment a holistic approach, verifying the potential of a wide range of NDTs available within the context of a restoration yard

La salvaguardia dell'ambiente e del biota nel settore dei beni culturali

In the past the unsuitable choices made when choosing products to be used for conservation actions related to artefacts of historic-artistic interest were mainly due to wrong assessments. More specifically this means: insufficient determination of the structure-aspect relation which characterises the original materials that make up the artefacts; insufficient knowledge of the behaviour of new materials due to natural ageing processes which might impoverish them or deprive them of specific qualities; lack of interest in measuring the medium-long term effects and interactions of the artefacts-products-environment system. The latter is sometimes capable of triggering new and more serious factors leading to the deterioration of the artefact sometimes causing even greater damage. In particular this study refers to the aspects related to the potential danger deriving from products used for the different types of conservation interventions on stone materials

Chapter Pyrgi: analysis of possible climatic effects on a coastal archaeological site

This work refers to an interdisciplinary study on the archaeological site of Pyrgi, an Etruscan harbour still under excavation, located on the Lazio’s coast in Santa Severa, in the province of Rome. The objective of the research is to assess the main cause of the floods and the time the water stays in the site to determine if the floods are periodic phenomena over time or random events for guarantee a correct conservation of the site . The study is based on the combined use of geomatic technologies, meteorological and climatic models, and hydrogeological knowledge

Pyrgi. Analysis of possible climatic effects on a coastal archaeological site

This work refers to an interdisciplinary study on the archaeological site of Pyrgi, an Etruscan harbour still under excavation, located on the Lazio’s coast in Santa Severa, in the province of Rome. The site in question is subject to frequent flooding which compromises its accessibility and delays the archaeological excavation operations. The study is based on the combined use of geomatic technologies, meteorological and climatic models, and hydrogeological knowledge of the examined site, to have a global view of the hazard to which it is exposed. Different geomatic techniques at different scales are used in the analysis. Large scale surveys are carried out to define the water networks and to monitor the site using satellite images. On a small scale, drone photogrammetry techniques are used to assess the morphology of the territory and eventual protection from natural hazards present in the site. Using these images, a detailed digital surface model (DSM) has been generated. The objective of the research is to assess the main cause of the floods and the time the water stays in the site and to determine if the floods are periodic phenomena over time or random events. The study was conducted using images captured by Sentinel 2 satellites processed at level 2-A. These images enabled the identification of the flooding periods of the site for the years of monitoring. The study was conducted by comparing the captured images with rainfall data, paying attention to extreme weather phenomena that occurred from 2012 to date. The rainfall data are provided by the National Department of Civil Protection to CNR-ISAC by an agreement between the two institutions. The same images have been compared with the wind data recorded by the anemometer located in the Civitavecchia harbour and the wave height data available from ERA5 reanalysis. Knowledge of the main cause of the floods and a possible periodicity will allow to plan correct conservation of the site through specific protection measures designed according to the hazards to which it is exposed

Evaluation of pictorial layers ageing by HyperSpectral Imaging

The possibility to perform a full characterization and identification of pigments in pictorial layers represents one of the most challenging targets in the field of cultural heritage, especially if their fulfillment is achieved setting up not invasive and not destructive analytical procedures. In this perspective, HyperSpectral Imaging (HSI) based sensing architectures, acting in the VIS-NIR and SWIR wavelength ranges, can represent an important diagnostic tool to realize the monitoring of paintings, as well as to evaluate their preservation status [1]. The goal of this study is to evaluate the alteration of different pictorial layers, as resulting from the combination of different supports, pigments and binders, according to different irradiation times. Starting from the result of recent studies [2], 6 pigments were thus mixed (i.e. red ocher, yellow ocher, chrome yellow, mineral blue, cobalt green and malachite) with four different binders (i.e. Arabic gum, gouache, egg tempera, and linseed oil), applying them on two different media (i.e. wood and canvas). The resulting samples have been aged in solar box and acquired at different aging times. Surface spectra of each sample were then acquired in VIS-NIR and SWIR ranges. Starting from the collected information (i.e. hypercube) chemometric techniques have been utilized to extract and handle pictorial layers information. The sequential application of Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLSDA) was then applied in order to study the pictorial layers spectra variations linked to the effects of the applied aging cycles. The sensing architectures have been designed and implemented, both at hardware and software level, in order to perform both in-situ (i.e. directly where the painting is) and ex-situ (i.e. at laboratory scale) analyses. The results showed as the developed modelling procedure allows to correctly predict sample characteristics and composition. Furthermore, it is objective, rapid and non-destructive. The implementation of such approach could allow to perform a full monitoring of the state of conservation and/or the characterization of materials and/or supports not easy to assess with conventional techniques

IDENTIFICAZIONE DI PIGMENTI IN STRATI PITTORICI MEDIANTE IMPIEGO DI IMAGING IPERSPETTRALE

La possibilità di poter caratterizzare i pigmenti all’interno di uno strato pittorico rappresenta una sfida nello studio dei dipinti, soprattutto mediante l’impiego di tecniche analitiche non distruttive e non invasive. L'utilizzo dell’imaging iperspettrale (HSI) come tecnica diagnostica per l’analisi degli strati pittorici e la valutazione dello stato di conservazione, appare di grande interesse per le sue potenzialità. Tale tecnica di analisi, infatti, è di tipo non distruttivo, non invasivo e, con implementazioni dell’hardware, può diventare portatile. La sua combinazione con tecniche chemiometriche permette di ottenere dati qualitativi e/o quantitativi sulle caratteristiche chimico-fisiche dei materiali investigati. Lo studio in corso [1-4] si pone quale obiettivo quello di valutare le possibilità offerte da un tale approccio analitico per l’identificazione dei pigmenti in strati pittorici. I sistemi iperspettrali impiegati sono ImSpector™ V10E (range spettrale VIS-NIR da 400 a 1000 nm) e SISUCHEMA XL ImSpector™ N25 (range spettrale SWIR da 1000 a 2500 nm). Vengono qui presentati alcuni dei risultati ottenuti dallo studio effettuato sui primi sei pigmenti presi in esame (ocra rossa, ocra gialla, giallo cromo, blu minerale, verde di cobalto e malachite), mescolati con quattro differenti leganti (gomma arabica, guazzo, tempera d’uovo, olio di lino con resine alchidiche) ed applicati su due tipologie di supporto pittorico (legno e tela). I provini di riferimento così realizzati sono stati acquisiti con HSI; i dati ottenuti (ipercubo) sono stati poi elaborati con metodi chemiometrici: Principal Component Analysis (PCA) e Partial Least Square-Discriminant Analysis (PLS-DA), mediante software PLS_Toolbox (Version 7.3, Eigenvector Research, Inc.) e Matlab® (Version 7.11.1 The Mathworks, Inc.). I primi risultati relativi ai sei pigmenti in esame, soprattutto nel range dello SWIR, hanno dimostrato che esiste una correlazione tra le firme spettrali dei pigmenti in polvere analizzati e quelle dei campioni realizzati mescolando i sei pigmenti con i quattro leganti applicati sui due supporti, prospettando, dunque, nuovi scenari analitici per la caratterizzazione degli strati pittorici. L'approccio analitico sviluppato permette di ottenere in maniera rapida e non distruttiva informazioni non solo sul tipo di pigmento, ma anche sul legante e sul supporto. Scopo ultimo è quello di aumentare i casi di studio su cui applicare la metodica: si stanno attualmente preparando e analizzando nuovi provini di pigmenti con diverse combinazioni di strati pittorici, al fine di condurre nuovi test non solo su campioni tal quali ma anche invecchiati in solar box con differenti tempi di esposizione. Un tale approccio analitico potrebbe consentire di eseguire un monitoraggio completo dello stato di conservazione di una superficie dipinta così come la caratterizzazione dei suoi materiali costitutivi, in confronto con altre tecniche analitiche convenzionali

A scientific approach in the recovery of the historic center of Rome: limits and potentialities of the “color plan”

The development of studies about conservation of historic centers has highlighted the importance of interventions on the color of the plastered facades. The study of a color plan in city centers has been the subject of numerous debates in Italy, particularly in complex cases such as the historic center of Rome. Over the past thirty years also the development of new products for the construction industry has introduced the problem of materials selection and evaluation of their compatibility in historic urban context. By a preliminary analysis of the current legislation it is clear only the definition of general precepts without giving clear rules for the restoration of plasters and colors. The aim of this study is to compare the results obtained from this survey with the current "Plan of protection of the urban image of Rome", to highlight the potentialities and limits of existing regulations and to better understand the tools to be used for the restoration of historic buildings

Caratterizzazione delle superfici dipinte

Premessa Al fine di caratterizzare gli elementi costitutivi delle superfici dipinte sono stati analizzati alcuni frammenti di intonaco provenienti dall’ambiente 25 della villa, in cui lo scavo, effettuato nel biennio 2012-2014, ha riportato alla luce differenti stratificazioni di materiale frammentario omogeneo dal punto di vista stilistico e collocabile fra il III e il IV stile pompeiano, compatibile con la seconda fase costruttiva della villa 1. Pertanto, in prima analisi, sono stati esaminati 14 campioni di intonaco dipinto rappresentativi delle principali cromie riscontrate sui frammenti analizzati (734 frammenti). Ai campioni è stata assegnata una sigla di riconoscimento (COT) con numero sequenziale

Diagnostics and Monitoring to Preserve a Hypogeum Site: The Case of the Mithraeum of Marino Laziale (Rome)

Conservation of hypogea and their accessibility by the visitors is a hard question, due to the interaction of different factors such as the intrinsic characteristics of the hypogeal environments and the presence of public. A particular case is represented by the Mithraeum of Marino Laziale, located a few kilometers away from Rome and accidentally discovered in the 1960s. The uniqueness of the discovery was the presence of a well-preserved painting of the Mithraic scene (II century A.D.) probably due to the oblivion of the place of worship over the centuries as well as the isolation from the outdoor environment. Unfortunately, despite a recent complete restoration and recovery of the archaeological area, which ended in 2015, the area was never open to the visitors and only two years after completing the works it was no longer safe to use. Hence, the need for a new planning of interventions starting from the deep knowledge of this cultural heritage and from the analysis of past incorrect actions to arrive at the opening—without any risk for the archaeological findings and visitors—and management of this site, never exposed to the public. Therefore, since 2018 a diagnostic campaign and microclimate monitoring have been started. The data collected during the two years of investigations have been fundamental to assess the conservation state of the hypogeal environment and the potential risks for the preservation of the three paintings (the Mithraic scene and two dadophores). Long-term monitoring of indoor environmental conditions assumes the role of an essential tool for the planning of preventive conservation strategies but also for the control of the site after its opening to the visitors. Furthermore, the characterization of the microclimate is non-invasive, sufficiently economical and accurate. In this paper, the characterization of surfaces in the Mithraic gallery through optical microscopy, UV fluorescence/imaging techniques, FT-IR spectroscopy, XRD and the microclimatic parameters variation in the presence or absence of visitors are used to define the strategies for the opening and fruition of the Mithraeum. The strategies for the sustainable fruition of this unique archaeological site have been defined through a conservation protocol approved by the Italian Ministry of Cultural Heritage and necessary for the site managers and curators of the Municipality of Marino Laziale to finally support its opening