Deep hydrophobization and graffiti protection as a certified all-in-one system
Scheidel-Chemie located in Hirschaid has developed a new surface protection in cooperation with Wismar University of Applied Sciences, hence, combining classical hydrophobization with permanent graffiti and surface protection. The colorless, non-film forming impregnations ensure that the aesthetics of architecture, the surface texture and color are permanently maintained, and that the treated substrate is permanently protected at a deep level, too.
Hydrophobization combined with graffiti protection
HydroGraff made by Scheidel has now combined hydrophobization and graffiti protection in a single product for the first time. The product is available in three versions: HydroGraff CC OS-A AGS cream, HydroGraff FL OS-A AGS liquid, and HydroGraff PC – premium façade cream. The products can be applied in easy working steps to nearly all substrates such as alkaline cement-bond surfaces, precast concrete elements, fair-faced concrete, absorbent clinkers or sand-lime bricks, for example. HydroGraff OS-A AGS products comply with the requirements regarding graffiti protection in accordance with BASt LT/LP AGS concrete as well as maintenance and repair measures in accordance with DIN EN 1504-2.
In addition, they fulfil the requirements regarding permanent graffiti protection in accordance with RAL Quality Association Anti-Graffiti e.V., Berlin. The tests carried out certify both OS-A AGS HydroGraff products an excellent cleanability even in case of various graffiti attacks. All HydroGraff products complement the well-proven Scheidel anti-graffiti system comprising graffiti and surface protection products adapted to the respective substrates. The section below gives three application examples:
Glonnterrassen embankment in Allershausen
Application example 1: The city of Allershausen near Munich has re-designed its town center in an extensive building project. As part of the project, the area around the small river Glonn, crossing the city, was converted into a new leisure area, the so-called „Glonnterrassen“ (Glonn Terraces). An air-entrained concrete was used to secure the bank side, the surface of the same was blasted and hence furnished with a consistent appearance. Since the concrete surfaces reach up to the sidewalk and are exposed to various environmental influences, the concrete needed a hydrophobing treatment. In winter increased freeze-thaw attacks with de-icing salts have to be expected, floods in spring. And, of course, the relatively large surface areas are also a temptation for graffiti writers.
The city of Allershausen‘s building authority considered this an ideal field of application for HydroGraff made by Scheidel. Following the respective call for tenders, a concrete surface covering 550 m² was impregnated with HydroGraff FL-OS-A AGS (liquid). The deep hydrophobization reliably protects the concrete against environmental influences, and the permanent graffiti protection facilitates the removal of smearing considerably. Quite secondarily, the impregnation had a positive side effect: The slight brightening of the surface color upgraded the visual appearance of the embankment, perfectly blending the selected pavement of the sidewalk.
Pedestrian underpass in Suhr/Switzerland
Application example 2: Reconstruction work and repair work at an underpass for pedestrians and cyclists in Suhr/Switzerland led to the fact that a building structure existed with new and old concrete surfaces mixed up and placed alongside each other. To create a consistent, uniform concrete protection, the client called for deep hydrophobization. As such, building structures are generally also targets for graffiti, the combination product Scheidel HydroGraff CC – OS-A AGS cream was used here. In order to prove the effect of deep hydrophobization, three core samples were taken by an independent engineering firm and the capillary water absorption as well as the water permeability were determined.
Result: HydroGraff CC – OS-A AGS cream meets the requirements of the Swiss standard SN EN 1504-2:2004 in an excellent way. The graffiti protection was confirmed in practice: Only a few weeks after the reconstruction, it was necessary to remove the first „work of art“ and the staff of the responsible public works service were more than just satisfied with the easy removal of the graffiti.
Precast concrete elements impregnated in the production process
Application example 3: The requirements on surface protection in terms of architectural concrete are very high. On the one hand, graffiti and paint attacks shall be removable easily and repeatedly without the need to renew the separation layer; on the other hand, the separation layer must not lead to any direct alterations of the surface such as turning white or darkening. The feel of the surface shall not be impacted by the surface protection either.
The very different concrete compositions used by the respective manufacturers are especially challenging when it comes to the impregnation of architectural concrete. Therefore, it is hardly possible to determine the appropriate surface protection without previous test areas and their evaluation. First applications have revealed that HydroGraff products can be integrated in the production process at the concrete plant: the product can be applied after a few days already, depending on the residual moisture. The field of application regarding impregnated precast concrete elements is ranging from façades to applications on floor areas.
Conclusion
According to the manufacturer, HydroGraff made by Scheidel provides the market with a hydrophobing product, for the first time, that ensures a reliable and permanent graffiti prevention, is suited to maintenance of building structures simultaneously, and offers a general surface protection against several kinds of contamination.
Text: Dipl.-Kfm. Georg Scheidel
