The objective of this research is to investigate future maintenance methods focusing on water behaviors in the PC superstructure of the road bridge that has been in service for 23 years after construction under severe chloride environment. In the detailed investigations from 8 years ago, it was found that this bridge was deteriorated by corrosion of epoxy coated reinforcing bars and remarkable pop-out of concrete inside box girders due to the action of water. After various countermeasures to control water inside concrete, it was revealed that no remarkable deterioration was found in 2019. Based on these results, the maintenance methodology from the viewpoint of water was proposed.
