Q.: Is there a limitation on chloride ions in concrete if the post-tensioning steel is located in ducts and will be encased in grease? Isn't that adequate protection for the steel?

A.: The Post-Tensioning Institute informs us that there is no difference in the limitation whether or not the steel is protected as you describe. Apparently the idea is to guard against the presence of chloride ions in case anything goes wrong with the intended protection.