Surface treatments and anti-graffiti agentsResearch and development are focused on how the surface treatments affect the durability of concrete. The objective is to prevent the degradation of concrete structures. Impregnation of natural stone is more common for the cultural heritage than for new objects.
Concrete and natural stone are porous materials. Surface treatments in the form of impregnation and hydrophobation can be used to reduce ingress of water into concrete, and thus prevent risk for reinforcement corrosion, frost damage and silica-alkali reaction. Dry surfaces are expected to have less biological growth and less dirt attached to the surface. It is important that hydrophobation not prevent water vapour permeability since impermeable layers can lead to frost damage.
Hydrophobation has been used for many years mainly on plastered and brick facades on vulnerable positions. Since 1980's concrete has been impregnated. For a successful hydrophobation the appropriate waterproofing, appropriate application techniques and evaluation methods for efficiency determination are required.
If a surface is unprotected the graffiti paints penetrate into concrete, stone, brick and plaster. This leads to a severe damage of the surface, followed by a costly cleaning process.
Graffiti protection is used to facilitate the clean-up of graffiti colours from a surface. There is a variety of graffiti protection products on the market, whose efficiency is of varying quality. Graffiti protection has been evaluated with the intention of discoloration and mechanical and physical influence of the surface.
Method of testing
There are no approved and effective testing standards in Europe to determine whether a graffiti protection is effective against graffiti paint and dirt on a certain type of surface. CBI has developed a new method for evaluating the effectiveness of the graffiti protection and work is underway to revise Vägverket instructions for testing and approval of the graffiti protection.
For more detailed information on graffiti protection, read about SAGA - The Swedish Anti-Graffiti Academy, download here.