“The key isn’t to apply as much material as possible,” explained Hossein Heydarinouri of Empa’s Structural Engineering laboratory. “The shape is much more important: An optimised geometry distributes stresses in such a way that the propagation of existing cracks is stopped or significantly slowed down.” For example, researchers from Empa and ETH Zurich were able to extend the service life of the damaged steel plates under investigation by up to four times as part of a master’s thesis project.