On the basis of studies conducted about 30 years ago, steel piles having a significant portion of their length driven below fresh groundwater tables showed only minor losses of metal due to corrosion.Previous investigators attributed the lack of corrosion to global cathodic self-protection of driven piles. Recent construction in Hartford, Connecticut, uncovered piles installed more than 30 years ago.Some showed losses of cross-sectional area greater than 50 percent.These piles were driven through layers of waste materials called miscellaneous fill. The results of an investigation into this unusual corrosion loss are presented. The cause of the corrosion is traced to a macro cell developed between contiguous layers in the miscellaneous fill that overrides the global protection normally found at mostpile installations in fresh water. Electrical characteristics of the macro cell are presented. Techniques for detecting areas that might develop these macro cells are outlined, and methods of protecting piles from their effects are discussed
Samenvatting