Ageing of concrete structures located in coastal environments is very actual challenge since a lot of them have been built from 30 to 50 years ago. Three main challenges are faced by companies and owners: diagnosis, reassessment and repair. The paper focuses on the last one and more precisely, on the repair of concrete beams of wharves in the tidal area. In fact, this zone is the point of confluence of a modeling challenge (non saturate conditions), a repair technique application (repair during the low level tide) and a real stake (most of the beams of concrete wharves located in this area).