The goal of this study was to find a correlation between cleaning efficacy of substrates protected with anti-graffiti systems (AGS) and their porosity, surface roughness, and composition as well as usability of the Technical Testing Guideline for Anti-Graffiti Systems (TP-AGS, issued by BASt) for natural stone and brick/clinker masonry. The results showed that the cleaning efficacy mainly depends on the porosity of the substrate and the type of AGS. Also, higher surface roughness contributed to a lower cleaning efficacy. The results showed also that concrete panels and cement joints in masonry represented the worst case. The color change of all substrate materials compared to concrete was mostly within acceptable limits. Gloss changes were significant for a number of substrates. In particular, several of the wax-treated low-porosity substrates exceeded the threshold value of 10. The limit of water vapor permeability of the AGS prescribed in the TP-AGS might be too high for natural stone substrates. In general, the TP-AGS is useful for the determination of the efficiency factor of anti-graffiti agents on various substrates.
In this article a comparative study of the behaviour of
different commercial anti-graffiti on natural stone and
brick is presented. 8 different European substrates were
selected and 4 commercial anti-graffiti of different
chemical nature were applied on these substrates. The
variations of their hydric properties and aspect (colour
and gloss) with regard to the untreated substrates were
later studied in the laboratory.
The results obtained permitted to assess the suitability of
4 of the main types of chemical formulations employed
to be used as anti-graffiti. This study concludes that the
sacrificial anti-graffiti with polymeric paraffins in its
composition presents the lowest reductions of the hydric
properties of the studied substrates, being also the
variations in colour the least perceptible.