Durability of Hydrophobic Treatments on Concrete Surface

• Applicant: Professor Dr.-Ing. Michael Raupach
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 169884052

Hydrophobic agents have already been used by early civilisations suchas the Mayans to protect buildings from moisture and climaticinfluences. The advantage of hydrophobic agents compared to painting orsealing is that the former are colourless and do not form films. Thisresults in an almost unchanged appearance of the surface after theapplication, which is of enormous importance for béton brut andlandmarked façades. Current hydrophobic agents for inorganic substratessuch as concrete, structural and decorative dimension stones, andbricks consist of organosilicon compounds. Lacking detailed knowledgeon the durability of such substances, the potential for real-lifeapplications such as the protection of cultural heritage sites remainslargely unused. Consequently, this project is concerned with thesystematic investigation of potential degradation mechanisms ofhydrophobic agents and the results will be used to compile a model thatallows predicting their life-time. The model will contain relevantparameters such as the type of concrete, the type of hydrophobic agent,and climatic influences. This will form the basis for the developmentof new hydrophobic agents. In addition, the model can be used to opennew fields of applications for hydrophobic treatments that areinaccessible today due to a lack of knowledge the concerning long-termstability. The topic contains certain urgency, since a number ofconcrete façades in particular those of cultural heritage sites arecurrently refurbished using low quality methods. This will result inirreparable surface damages which could be prevents using suitablehydrophobic agents.

• DFG Programme: Research Grants