Study on the Application of Anti-Graffiti Systems on Natural Stones and Concrete

The goal of this study was to find a correlation between cleaning efficacy of substrates protected with anti-graffiti and their porosity, surface roughness, composition and as well as usability of the Technical Testing Guideline for Anti-Graffiti Systems (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 anti-graffiti. 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 colour change of all substrate materials compared to concrete was mostly within the 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 vapour 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.