Evaluation of Accelerated Ageing Tests for Metallic and Non-Metallic Graffiti Paints Applied to Stone
Articolo
Data di Pubblicazione:
2017
Citazione:
Evaluation of Accelerated Ageing Tests for Metallic and Non-Metallic Graffiti Paints Applied to Stone / P. Sanmartin, F. Cappitelli. - In: COATINGS. - ISSN 2079-6412. - 7:11(2017 Oct 30), pp. 180.1-180.16. [10.3390/coatings7110180]
Abstract:
Graffiti are increasingly observed on urban and peri-urban buildings and their removal
requires a huge financial outlay by local governments and agencies. Graffiti are not usually removed
immediately, but rather over the passage of time, viz. months or even years. In this study,
which forms part of a wider research project on graffiti removal, different methods (gravimetric
analysis, examination of digital images, colour and infrared measurements) were used to evaluate the
performance of accelerated ageing tests (involving exposure to humidity, freeze-thawing cycles and
NaCl and Na2SO4 salts) for graffiti painted on stone. Silver (metallic) and black (non-metallic) graffiti
spray paints were applied to two types of igneous rock (granite and rhyolitic ignimbrite) and one
sedimentary rock (fossiliferous limestone, i.e., biocalcarenite). The metallic and non-metallic graffiti
spray paints acted differently on the stone surfaces, both chemically and physically. Older graffiti
were found to be more vulnerable to weathering agents. The ageing test with NaCl and particularly
Na2SO4, both applied to granite, proved the most severe on the paints, yielding more detrimental
and faster artificial ageing of the type of material under study.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
accelerated ageing tests; graffiti; coating; stone protection; gravimetric analysis; colour measurements; infrared spectroscopy
Elenco autori:
P. Sanmartin, F. Cappitelli
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