Corrosion of steel bars in concrete is a major cause of deterioration of reinforced concrete structures exposed to the marine environment that leaded to a loss of multi-billion US$ every year. A lot of researches were executed on this matter since long ago. However, studies on this matter are still necessary in order to ensure long-term durability of marine RC structures. With this aim, several conclusions are drawn here based on the investigations on several research topics regarding the durability of concrete structures under marine environment.
　Detail electrochemical as well as physical evaluations of steel bars corrosion were carried out on several experimental programs in the last six years, such as corrosion of steel bars with respect to its orientation in concrete, corrosion of plain and deformed steel bars in concrete, corrosion of steel bars in cracked and uncracked concrete made with ordinary, fly ash and slag cements. The summaries of these investigations are reported here with the following conclusions:
・Voids/gaps at the steel-concrete interface cause earlier corrosion and accelerate the rate of corrosion of steel bars in concrete,
・Deformed bar is more prone to corrosion compared to plain bar,
・Slag cements with higher amount of slag content, such as Slag Cement of Type C shows the best performance against chloride ingress and corrosion of steel bars in concrete,
・With the continued exposure under marine environment, narrow cracks are healed and stopped the corrosion process.