Atmospheric agents and air pollution play a key role in the degradation of surfaces of historical buildings and monuments. One of the most diffused decay processes affecting both natural and artificial carbonate materials exposed to the urban atmosphere is the formation of sulfate-based deposits (i.e. “black crusts”). Moreover, the cleaning of exposed surfaces represents a crucial step in the restoration procedure of stone monuments and works of art. For the restorers involved in the cleaning of stone surfaces, it is crucial to know in real time the effectiveness of the adopted procedures in order to opportunely optimize and tune their interventions. The present study focuses on the evaluation of the efficacy of different cleaning methods (i.e. laser, chemical and microbial) for the “black crusts” on marble surfaces belonging to a column of Loggia di Baccio d’Agnolo in Santa Maria del Fiore Cathedral (Florence) employing SWIR (Short Wave Infrared) hyperspectral investigation. The SWIR technique is fully non-invasive and allows to gain spectral information in both the visible (VIS) and near infrared (NIR) regions using a portable spectroradiometer (ASD Fieldspec® 3). The procedure consisted in the detection of gypsum amount still present onto the stone surfaces after partial cleaning steps. The resulting SWIR spectra were modelled through a full profile approach proposed by Suzuki et al. (2018), in order to obtain a reliable and efficient spectral decomposition and an esteem of the amount of gypsum left on the surface after each cleaning step/procedure. With a support of a dedicated software relying on the approach of Suzuki et al (2018), to be implemented in the next future, the acquisition of the spectra and the determination of the gypsum residues submitted the cleaning treatment may be in principle obtained in less than one minute for surface spots having a surface up to ~20 cm2. In the case of the column under study, the best cleaning results were obtained for chemical cleaning and the combined use of laser and biological procedures.
Hyperspectral sensor: a practice tool to evalute the efficacy of cleaning procedure / Vettori S., Verrucchi M, Di Benedetto F., Gioventù E., Benvenuti M., Pecchioni E., Costagliola P., Moretti S.. - ELETTRONICO. - Volume Abstracts:(2019), pp. 189-189. (Intervento presentato al convegno Il Tempo del Pianeta Terra e il tempo dell'uomo: le geoscienze tra passato e futuro. tenutosi a Parma nel 16-19 Settembre) [10.3301/ABSGI.2019.05].
Hyperspectral sensor: a practice tool to evalute the efficacy of cleaning procedure.
Verrucchi MMembro del Collaboration Group
;Di Benedetto F.Membro del Collaboration Group
;Benvenuti M.Membro del Collaboration Group
;Pecchioni E.Membro del Collaboration Group
;Costagliola P.Membro del Collaboration Group
;Moretti S.Membro del Collaboration Group
2019
Abstract
Atmospheric agents and air pollution play a key role in the degradation of surfaces of historical buildings and monuments. One of the most diffused decay processes affecting both natural and artificial carbonate materials exposed to the urban atmosphere is the formation of sulfate-based deposits (i.e. “black crusts”). Moreover, the cleaning of exposed surfaces represents a crucial step in the restoration procedure of stone monuments and works of art. For the restorers involved in the cleaning of stone surfaces, it is crucial to know in real time the effectiveness of the adopted procedures in order to opportunely optimize and tune their interventions. The present study focuses on the evaluation of the efficacy of different cleaning methods (i.e. laser, chemical and microbial) for the “black crusts” on marble surfaces belonging to a column of Loggia di Baccio d’Agnolo in Santa Maria del Fiore Cathedral (Florence) employing SWIR (Short Wave Infrared) hyperspectral investigation. The SWIR technique is fully non-invasive and allows to gain spectral information in both the visible (VIS) and near infrared (NIR) regions using a portable spectroradiometer (ASD Fieldspec® 3). The procedure consisted in the detection of gypsum amount still present onto the stone surfaces after partial cleaning steps. The resulting SWIR spectra were modelled through a full profile approach proposed by Suzuki et al. (2018), in order to obtain a reliable and efficient spectral decomposition and an esteem of the amount of gypsum left on the surface after each cleaning step/procedure. With a support of a dedicated software relying on the approach of Suzuki et al (2018), to be implemented in the next future, the acquisition of the spectra and the determination of the gypsum residues submitted the cleaning treatment may be in principle obtained in less than one minute for surface spots having a surface up to ~20 cm2. In the case of the column under study, the best cleaning results were obtained for chemical cleaning and the combined use of laser and biological procedures.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
