In this paper, a term “PC sheet pile” is used as “Pre-stressed Concrete Sheet Pile”. PC sheet pile has ever been used widely as river revetment, retaining wall, etc. However, it has not been used in port and harbor structures. The reason for this is that the environmental condition of port and harbor is severe for steel corrosion in concrete structures. Therefore, the adequate countermeasure for corrosion prevention is necessary in port structures. In a viewpoint of sheet pile setting, the sheet pile thickness should be as small as possible. On the other hand, in the viewpoint of corrosion prevention, the cover thickness of steel bars should be as larger as possible. Due to the lack of research data on adequate cover thickness, PC sheet pile has not been used for port and harbor structures. The objective of this study is to obtain experimental data to discuss about an adequate cover thickness of PC sheet piles under severe corrosive environments, such as marine conditions.In this study, PC sheet pile model specimens and cylindrical control specimens were exposed under artificial accelerating corrosive condition. Based on this experimental data, the durability of PC sheet pile under corrosive environments is quantitatively evaluated, and an adequate cover thickness is discussed based on the durability evaluation. Main conclusions obtained in this study are as follows.
1) Chloride ingress into concrete with compressive strength 70N/mm2 is much smaller than that of concrete with ordinary strength, such as 24 N/mm2.
2) Steam curing does not have an negative influence on concrete quality.
3) Inclusion of blast furnace slag leads to the shift of electrical potential to lower value, however, the steel corrosion is very small.
4) An adequate cover thickness depends on the environmental condition and required service life of the structure. If the required corrosion initiation time is 20 years, the minimum coverthickness becomes 30mm, as for 30 years it is 40mm and as for 50 years it is 50mm.