PSI - Issue 55

Jéssica D. Bersch et al. / Procedia Structural Integrity 55 (2024) 57–63 Bersch et al. / Structural Integrity Procedia 00 (2023) 000 – 000

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which may be applied seeking to remove graffiti over permanent protective products (Moura et al., 2017). By studying the available methods for graffiti removal, Sanmartín et al. (2014) identified that typical chemical substances may penetrate the substrate, damaging it irreversibly, further than causing environmental and health hazards; thus, new environmentally safe methods should be developed for graffiti removal from porous materials, including bioremediation (Sanmartín et al., 2014). Thus, further than the essential need for an adequate choice of anti-graffiti products (Rossi et al., 2016), investigating the cleaning procedures required to remove the graffiti paint is fundamental regarding the expected environmental impacts from the coatings. If removal products will actually be used, the ideal is to clean graffiti with less aggressive solutions, like mixtures of aliphatic and aromatic organic solvents or xylene; if, unfortunately, the achieved results are not acceptable, more aggressive removers, including methylethylketone, may be a solution (Rossi et al., 2016). Roviello et al. (2022) studied two commercial anti-graffiti products, one of which was permanent, nano-based and considered environmentally sustainable, and the other was semi-permanent. As graffiti removal method, solely cleaning cycles with hot water at 60 °C were carried out; the removal method could effectively clean the surface of porous materials, including tuff, protected with the permanent product, which proved more effective than the semi permanent anti-graffiti (Roviello et al., 2022). Pedroso et al. (2022) quantified the environmental and economic impacts of protection solutions to be applied on ETICS; regarding anti-graffiti products, their environmental impacts were reported to depend highly on the number of cleaning cycles required to remove the graffiti application, even more than in the service life of the protective solutions. Therefore, the application of sacrificial products in buildings highly prone to vandalism can lead to very high environmental and economic impacts (Pedroso et al., 2022). However, especially considering the protection of cultural heritage, Roviello et al. (2022) emphasized the need for new anti-graffiti formulations comprising not only hydrophobicity but also sacrificial properties, besides environmental sustainability, focused on ecologic aspects and human health. Moreover, complexities arise from each specific case and should be considered according to the building façade to be protected. 4. Conclusions The present study discussed the efficiency of anti-graffiti products in the context of climate change and the arising impacts and scenarios resulting from the performance and durability of the protective solutions. The topic ’s relevance is emphasized by the recurrent application of unauthorized graffiti paints in urban areas, understood as vandalism mainly in historical buildings, and the challenges posed by climate change upon the durability and resilience of buildings and construction materials. About polluted environments, further studies should include diverse air pollutants since varied anti-graffiti products may respond differently to the imposed air quality, and graffiti paints themselves are also affected by the interaction with air pollution throughout time, impacting cleaning needs. Concerning the existing effects caused by environmental factors on anti-graffiti products, understanding their long-term behavior is essential, mainly due to the involved maintainability, energy, costs, and impacts. Different scenarios of study must be taken into account, considering not only the nature of the anti-graffiti products but also the substrates to be protected and their cultural value; maintenance strategies should be planned within the specific application context. Further attention should be dedicated to the life cycle assessment and life cycle costing of anti-graffiti products, and more research should address the search for environmentally friendly protective solutions and cleaning methods. Acknowledgements The authors thank CERIS (Civil Engineering Research and Innovation for Sustainability) research unit from IST (Instituto Superior Técnico), PPGCI (Programa de Pós-Graduação em Engenharia Civil: Construção e Infraestrutura) from UFRGS (Universidade Federal do Rio Grande do Sul), CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico). The authors are grateful for the FCT (Foundation for Science and Technology) support through funding UIDB/04625/2020 from CERIS research unit. The first author wants to thank FCT for the grant 2023.05316.BD.