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- A XANES approach to the blue pigments in ceramic heritage [Resumo]Publication . Coutinho, ML; Veiga, JP; Ruivo, Andreia; Silva, Teresa; Salas-Colera, Eduardo; Bottura Scardina, Silvia; Lima, Augusta; Figueiredo, Elin; Cotte, Marine; Lima, M.M.R.A.
- The case study of the medieval town walls of Gubbio in Italy : first results on the characterization of mortars and bindersPublication . Carvalho, Fernanda; Lopes, Andreia; Curulli, Antonella; Silva, Teresa; Lima, M.M.R.A.; Padeletti, Giuseppina; Ronca, Sara; Padeletti, Giuseppina; Veiga, JPABSTRACT: Good conservation and restoration practices of cultural heritage assets rely on the knowledge of original materials. In the framework of the HERACLES Project (HERACLES—HEritage Resilience Against CLimate Events on Site, H2020 Grant Agreement 700395), dealing with the effects of climatic actions and natural hazards on built heritage, a set of important heritage sites are currently under study to improve their resilience against climate events. Among these are the medieval Gubbio Town Walls in Italy. The present work focuses on the mortars and binders of this monument and collected samples related to different parts of the Walls, corresponding to various historical periods of construction and interventions. They were characterized to determine their minerochemical composition, thermal behavior, and morphology. For that purpose, ex-situ laboratory techniques, such as X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), polarized light microscopy (PLM), scanning electron microscopy (SEM), and simultaneous differential thermal analysis and thermogravimetry (TG-DTA) were used to discern trends in different sampling areas due to construction/reconstruction periods and building techniques.
- Historical lime-based flooring mortars from the Church of Santa Maria de Alcobaça monastery (12th century), Portugal: A multi-analytical approachPublication . Carvalho, Fernanda; Nunes, A.; Pagará, A.; Costeira, I.; Silva, Teresa; Lima, M.M.R.A.; Veiga, JPABSTRACT: The Monastery of Alcobaça houses in reserve the ceramic tiles that adorned the floor of the church's apse. These tiles were removed during rehabilitation works and many preserve part of their original fixing mortars. A comprehensive analysis of 21 samples was conducted using a multi-analytical approach (X-ray fluorescence, X-ray diffraction, scanning electron microscopy–energy-dispersive X-ray spectroscopy, μ-Raman spectroscopy, thermogravimetry–differential thermal analysis, optical microscopy, and colorimetry). Results suggest compositional variations in the samples from the back and sides of the ceramic tiles; however, the mineralogy and general characteristics of the aggregates remained consistent between the samples and are coherent with the local geology, suggesting a shared historical origin.
- The case study of the medieval town walls of Gubbio in Italy : first results on the characterization of mortars and binders [Resumo]Publication . Carvalho, Fernanda; Padeletti, Giuseppina; Curulli, Antonella; Montesperelli, Giampiero; Lima, M.M.R.A.; Lopes, Andreia; Silva, Teresa; Veiga, JP
- Mortars from the Palace of Knossos in Crete, Greece: A Multi-Analytical ApproachPublication . Carvalho, Fernanda; Sousa, Pedro; Leal, Nuno; Simão, J.; Kavoulaki, Elissavet; Lima, M.M.R.A.; Silva, Teresa; Águas, Hugo; Padeletti, GiuseppinaABSTRACT: The study of building materials constituting cultural heritage is fundamental to understand their characteristics and predict their behavior. When considering materials from archaeological sites, their characterization can provide not only relevant information for a broader understanding of the site and its importance and significance but can also increase knowledge about ancient materials and their performance. The Palace of Knossos is a very important archaeological site in the European history context, and its preservation benefits from the characterization of the constituent materials. Samples of mortars from this monument were collected under the scope of the H2020 HERACLES project, where a multi-analytical approach was chosen using established protocols for the different sample typologies. Instrumental techniques such as optical microscopy (OM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and simultaneous thermogravimetry and differential thermal analysis (TG-DTA) were used for the chemical, mineralogical, and morphological characterization of these mortar samples. The results indicate that the majority are lime mortars, both aerial and hydraulic, but gypsum-based mortars were also identified. Differences in the chemical composition of the samples in distinct areas of the monument allowed us to reflect on the variety of materials used in the construction of the Palace of Knossos.
- Mortars from the Monastery of Santa Maria de Alcobaça, in Portugal: characteristics and functionsPublication . Carvalho, Fernanda; Lima, M.M.R.A.; Silva, Teresa; Nunes, A.; Pagará, A.; Costeira, I.; Leal, Nuno; Simão, J.; Galhano, Carlos; Veiga, JP
- Bedding mortars from medieval ceramic flooring from the Alcobaça Monastery in PortugalPublication . Carvalho, Fernanda; Nunes, A.; Pagará, A.; Costeira, I.; Silva, Teresa; Leal, Nuno; Simão, J.; Galhano, Carlos; Águas, Hugo; Lima, M.M.R.A.; Veiga, JPABSTRACT: Bedding mortars are fundamental materials to ensure the stability of titles, especially in the case of flooring which withstand the impact of people circulation. In a church, the quality of mortars, tiles pieces and their maintenance over time can be decisive for pavement durability. Inside the church of Santa Maria de Alcobaça Monastery, stone slabs are currently the main and the most applied type of paving in terms of covered area.
- Cultural Heritage, Materials Science and Synchrotron Radiation: a perspective from a group of Portuguese usersPublication . Veiga, JP; Coutinho, ML; Silva, Teresa; Figueiredo, Elin; Lima, M.M.R.A.; Saraiva, A.S.; Carvalho, FernandaABSTRACT: In this communication, examples to be presented are related to ancient ceramics, glasses, archaeological slags, inorganic pigments and lithologic materials where we were able to gain new insights into composition, structure and degradation processes, contributing to their preservation and interpretation for future generation.
- An insight into the firing conditions of Chinese blue-and-white porcelain through XANESPublication . Coutinho, ML; Veiga, JP; Ruivo, Andreia; Silva, Teresa; Salas-Colera, Eduardo; Bottura Scardina, Silvia; Lima, Augusta; Figueiredo, Elin; Cotte, Marine; Lima, M.M.R.A.ABSTRACT: Chinese blue-and-white porcelain is found in archaeological excavations worldwide, being significant evidence of global trade routes and cultural exchange. Synchrotron radiation-based techniques have been applied for studying cobalt speciation to establish a correlation between the cobalt and iron oxidation state and local coordination environment in the rich blue shades of Chinese blue-and-white porcelain. However, the relationship between the firing atmosphere conditions and the speciation of cobalt has not been established yet. In this study, underglaze blue models were produced and fired in air or under reducing atmospheres to ascertain the effect of the firing atmosphere in cobalt and iron speciation. The experimental results were compared with data obtained on historical samples of ancient porcelain shards. The microstructure and colour of the produced underglaze blue models were investigated by variable pressure scanning electron microscopy (VP-SEM-EDS), using a hyperspectral imaging camera (Vis-SWIR reflectance spectroscopy) and colorimetry. The formal valence and coordination of cobalt and iron ions of the glaze were determined by X-ray absorption spectroscopy (XAS), particularly X-ray absorption near edge structure (XANES), using synchrotron radiation. Spectral features demonstrated that both cobalt and iron speciation were affected by the firing atmosphere and therefore could be used to ascertain the firing atmosphere.
- Characterization of Tableware from Fábrica de Loiça de Sacavém : Linking Analytical and Documental ResearchPublication . Coutinho, ML; Veiga, JP; Ruivo, Andreia; Silva, Teresa; Bottura Scardina, Silvia; Lima, M.M.R.A.; Pereira, Carlos; Dias, Ana Carvalho; Dias, Luis; Vandenabeele, Peter; Roseiro, J. CarlosABSTRACT: Fabrica de Loica de Sacavem (ca. 1858-1994) was among the first to produce white earthenware in Portugal, becoming one of the country's leading ceramic manufacturers during the late 19th to early 20th centuries. Research on white earthenware has accompanied the growing interest in post-industrial archaeology but is still poorly explored compared to more ancient ceramic productions. This study focused on the ceramic body, glazes, and colourants of tableware produced by Fabrica de Loica de Sacavem during the first 50 years of its activity (1859-1910). A multi-analytical approach was selected to investigate the chemical and mineralogical composition of the ceramic body, glaze, and pigments using optical microscopy, variable-pressure scanning electron microscope energy-dispersive X-ray spectroscopy (VP-SEM-EDS), mu-Raman spectroscopy, mu-X-ray Diffraction (mu-XRD), and reflectance spectroscopy (hyperspectral image analysis). The studied tableware was produced with a Ca-poor siliceous-aluminous white earthenware ceramic body covered with transparent alkali lead or lead borosilicate glaze, and most colourants were complex Cr-based pigments. These results are in agreement with the little documental evidence from this period found in the manufacturer's archives.