Ultrasonic nondestructive testing of building materials for the diagnosis and characterization of the decay due to salts crystallization

The possibility to use ultrasonic nondestructive testing for the diagnosis and characterization of decay in building materials due to salts crystallization is here investigated. Salts crystallization is one of the main sources of decay for stone materials, especially for cultural heritage items underwater or exposed to water, and its early detection as well as a continuous monitoring is highly desirable. Currently, this often requires the use of destructive methods and the sampling of the items under inspection. This work shows promises to the successful use for this purpose of ultrasonic nondestructive testing.

Environmental impact assessment on the Monza cathedral (Italy): A multi-analytical approach

This research deals with the characterization of black crusts collected from the Dome of Monza (Milan, Italy). Air pollution is responsible for the degradation of historical buildings surfaces. In urban and industrial areas, the degradation process is accelerated, due to carbonaceous particles and heavy metals emitted by combustion processes which contribute to the formation of black crust (BCs). In this study the characterization of BC was performed using different analytical techniques such as: HRSEM-EDX, IC, LA-ICP/MS and digital image analysis. In particular, the research focused on the study of "heavy metals" which contribute to the identify the main sources of pollution responsible fo…

The first archaeometric characterization of obsidian artifacts from the archaeological site of Samshvilde (South Georgia, Caucasus)

This paper presents the first results about the provenance of obsidian fragments recovered in the archaeological site of Samshvilde (South Georgia, Caucasus) with the aim to obtain knowledge related to the network distribution and procurement of obsidian in Georgia. The geochemical characterization of thirty archaeological finds was obtained by the LA-ICP-MS method, an almost non-destructive technique capable of chemically characterizing the volcanic glass. A comparison of geochemical results obtained on both archaeological artefacts and geological samples collected from Chikiani outcrop in Georgia, together with literature data of southern Caucasus and eastern Turkey, allowed us to define …

Salt extraction from lime-based mortars: An experimental study using different poultice formulations

Abstract The extractive capability of soluble salts in poultices treatments currently used in mortar conservation (ArbocelTM plus sepiolite; ArbocelTM, sepiolite and sand; Westox-Cocoon®) were tested to evaluate their efficiency and compatibility with specific mortar substrate. The pore size distribution of the experimental mortar substrate and of the blank dried poultices were preliminarily accomplished by mercury intrusion porosimetry (MIP). Desalination tests were carried out on specifically-formulated mortars after capillary absorption of Na2SO4 0.3 M solution. The efficiency of salt extraction was measured by means of electrical conductivity meter and ion chromatography. Among the test…

Damage monitoring on carbonate stones: Field exposure tests contributing to pollution impact evaluation in two Italian sites

During the last decades, many studies have been carried out on environmental monitoring in specific sites aiming at their protection and conservation; however, researches focused on the direct implications, in terms of quantitative evaluation of stone deterioration, of these monitoring actions are still scarce. This experimental work aims at monitoring the degradation processes affecting historical buildings constituted by carbonate stones. Specifically, specimens of Carrara marble and two limestones largely used in the Sicilian Baroque architecture, namely Noto and Comiso stones, were exposed outdoor in two Italian sites (Catania and Palermo), which are characterized by different environme…

Pore structure and water transfer in Pietra d’Aspra limestone: A neutronographic study

Neutron radiography (NR) was here applied to study the effects of two different commercially available consolidants on the water absorption properties in a particular type of limestone (biocalcarenite), known as Pietra d’Aspra stone, which is one of the most extensively used lithotypes in Sicilian Baroque buildings. Our attention was mainly focused on the evaluation, using a fast and nondestructive visualization of water motion through capillarity, of the effectiveness of such layers as consolidating agents in view of preserving and maintaining both old and modern structures. The biocalcarenite was treated with nanosilica (Nano Estel®) and nanolime (CaLoSil®) by brushing it until full satur…

Ceramics from Samshvilde (Georgia): A pilot archaeometric study

Abstract This archaeometric study deals with seven samples of prehistoric pottery and, for the first time in Georgian studies, thirteen samples of glazed medieval pottery. All specimens were collected at Samshvilde, the most remarkable archaeological complex in southern Georgia and believed to represent locally-manufactured products. Two additional samples of raw materials composed of clay, silt, and sand were collected near the site and used to compare composition. Several analytical techniques were applied: Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), X-ray Diffraction (XRD) and X-ray Fluorescence (XRF). The results allowed to build a c…

Metals distributions within black crusts sampled on the facade of an historical monument: The case study of the Cathedral of Monza (Milan, Italy)

This research deals with the characterization of black crusts collected from Dome of Monza. Black crusts (BC) can be formed as a result of different chemical and physical reactions between the stone surface and environmental factors (such as gaseous pollutants, aerosol particulate matter and its specific chemical constituents-the carbonaceous fraction and the metals); therefore, they are considered as a passive sampler of pollutants. The specific focus of the current work is the study of the metals and their distribution within the samples. To characterize BC, several techniques were used such as: HRSEM-EDX, IC and LA-ICP/MS. This integrated approach allowed us to gain information about the…

Anti-fouling additives for the consolidation of archaeological mortars in underwater environment: Efficacy tests performed on the apsidal fishpond of Castrum Novum (Rome, Italy)

This paper deals with the formulation of innovative mortars for the consolidation of archeological structures in underwater environment. The research was conducted within the frame of the MaTaCoS project (Advanced materials and technologies applied to the conservation of underwater cultural heritage) funded by MISE (Italian Ministry of Economic Development). The project concerns the design of advanced tools and methods for the protection of Underwater Cultural Heritage, through specific cleaning and consolidating procedures to be applied directly in situ. The fishpond of the archaeological site of Castrum Novum (Santa Marinella, Rome, Italy) was chosen as a pilot site for experimentation. I…

A Combined Non-Destructive and Micro-Destructive Approach to Solving the Forensic Problems in the Field of Cultural Heritage: Two Case Studies

The present paper discusses the importance of non-destructive and micro-destructive technology in forensic investigations in the field of cultural heritage. Recent technological developments and the wide availability of modern analytical instrumentation are creating new possibilities for performing scientific measurements and acquiring data directly on-site—thereby limiting, where possible, sampling activity—as well as learning about the technologies and materials that were employed in the past to create cultural assets. Information on periods, chemical composition, manufacturing techniques, etc., can be gathered more easily. Overall, the benefits of on-site forensic investigations are mult…

New insights about the consolidation of archaeological mortars located in underwater environment: The case study of the apsidal fishpond of Castrum Novum (Santa Marinella, Rome, Italy)

This work is part of a research project titled MaTaCoS (Advanced materials and technologies applied to the conservation of underwater cultural heritage) funded by the Italian Ministry of Economic Development (MISE), concerning development of innovative tools and methods for the protection of Underwater Cultural Heritage, with particular regard to cleaning and consolidating procedures to be carry out directly in situ. The fishpond of the archaeological site of Castrum Novum (Santa Marinella, Rome, Italy) was chosen as a pilot site for experimentation. Castrum Novum was a Roman colony whose ruins are located between Torre Chiaruccia and Casale Alibrandi. The archaeological site lies on a wide…

Innovative experimental approaches applied to the study of ceramics from underwater archaeological excavations

Consolidation of earthen building materials: a comparative study

The consolidation and protection of mud bricks are a challenge in the field of conservation of archeological sites. One of the solutions is represented by the coverage of the entire excavation that assures a protection against mud dissolution. Unfortunately, this is not always feasible, both for economical and practical issues. For these reasons, alternative solutions are needed. In this work, laboratory experimentation has been carried out in order to test the efficacy of some products to slow down the dissolution process and increase the brick toughness. Three typologies of raw materials taken from different outcrops (one from the Republic of Azerbaijan and two from Calabria region, Italy…