Efflorescence and crusts in Cultural Heritage from the island of Crete

Fernanda Carvalhoa*, Antonella Curullib, Elissavet Kavoulakic, Elpida Politakic, Elissavet Katsavelic, Aristeidis Dokometzidisc, Angeliki Psaroudakic, Maria Margarida R. A. Limaa, Giampiero Montesperellid, Sara Roncae, Hugo Águasa, Giuseppina Padelettib, João Pedro Veigaa 

a*CENIMAT/I3N—Centro de Investigação em Materiais, UNINOVA—Instituto de Desenvolvimento deNovas Tecnologias, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia,Universidade Nova de Lisboa, 2829-516 Caparica, Portugal

bCNR Consiglio Nazionale delle Ricerche, ISMN—Instituto per lo Studio dei Materiali Nanostrutturati,Via Salaria km 29.5, Monterotondo, 00015 Rome, Italy

cEPHORATE of Antiquities of Heraklion, Xanthoudidou & 1 Chatzidaki str, Heraklion 71202, Greece

dDipartimento di Ingegneria dell’Impresa, Università di Roma Tor Vergata, INSTM—Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, via della Ricerca Scientifica, 00133 Rome, Italy

eDipartimento di Scienze della Terra, La Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Rome, Italy

Efflorescence of salts are quite common in built heritage. They can occur both inside and outside the buildings, according to the conditions for the solubilization and crystallization cycles. In general, they are composed of soluble salts, but other efflorescence and crusts can also occur. The damage caused by salt efflorescence may be related both to chemical processes of dissolution of the substrate, and to the physical processes of stresses created by the development of crystals, which may result in the decay of the substrate, i.e. salt concretions and other visual changes. When the built heritage is located on an island, such as Crete, Greece, it is expected that the influence of the sea is particularly important for the formation of specific type of efflorescence and salt crusts. Under the HERACLES Project, efflorescence and salt crusts were studied in two emblematic historical monuments: the Koules fortress and the Palace of Knossos. The Koules fortress is located on the coastal line, by the sea while the Palace of Knossos is located approximately 6 km away, in the southeast direction. For this study, the samples were analysed with a set of ex-situ techniques as optical microscopy (OM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy, in order to establish the minerochemical and morphological characteristics of the crystals and to associate the possible causes of these problems.

[1] This work was supported by the European Union’s Framework Programme for Research and Innovation HORIZON 2020 under Grant Agreement 700395 project HERACLES.

Acknowledgment to the Portuguese Foundation for Science and Technology (FCT) UID/EAT/00729/2013 and EAT/00729-3 by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT—Portuguese Foundation for Science and Technology under the project number POCI-01-0145-FEDER-007688, Reference UID/CTM/50025/2013 NOVA.ID.FCT

Abstract presented in the Conference Materiais 2019, 14-17 Abril 2019, Lisboa, Portugal