Efectividade e nocividade dos procedementos de limpeza de grafitis e avaliación de produtos antigrafiti en pedras do patrimonio cultural

Nowadays, graffiti as a vandalism act affect historical buildings and monuments worldwide and many cities have to spend huge amounts of money in graffiti cleaning. Therefore, a topic of great interest is the development of a suitable procedure that can permit to achieve a satisfactory cleaning in terms of graffiti removal and minimum damage induced in the substrate. In fact, sometimes, the cleaning procedure by itself can cause serious damages which are obviously unacceptable in the field of conservation of the Architectural Heritage. In this sense, it may be recommended to apply anti-graffiti products on the stone surface in order to avoid the application of such severe cleaning procedures. Moreover, it seems very useful to perform the optimization of the cleaning procedure depending on the different type of stone and graffiti paint employed. On one hand, a relevant goal of this research project will be the evaluation of the effectiveness achieved by different cleaning procedures. Different common types of stones in the Cultural Heritage architecture mostly employed in the historical city centre of Torino (Italy) will be used (granite, limestone, travertine, gneiss, etc.). Different kinds of graffiti products (spray paint, markers and dabbers) will be applied in the stone specimens. Regarding to the cleaning techniques, mechanical (hydrocleaning with pressurized water), chemical (solvents, commercial remover products) and laser (different pulse durations and wavelength will be employed) procedures will be tested. On the other hand, this research project aims to the evaluation of the effectiveness and durability of anti-graffiti coatings on Cultural heritage stones. Different anti-graffiti products (both sacrificial and permanent) will be applied on the stone specimens and the results achieved by cleaning treatments will be compared with those performed on untreated stone surfaces. The most suitable treatments or cleaning procedures for Architectural Heritage stones will be determined