Predicting the remaining service life of land concrete by steel corrosion

This paper presents the prediction of remaining service life of the land concrete as distinguished from the marine concrete. This study assumes that the land concrete is deteriorated by following three cases: carbonation, using sea sand and using deicing salts. In case of carbonation deterioration, statistical analysis and the depth of carbonation front are considered. This depth is assessed about 3.6-8.3 mm and can give more exact prediction than just carbonation depth by phenolphthalein. In case of using sea sand, various specimens considering chloride contents, carbonation accelerating, cover depth, relative humidity and water cement ratio are measured by linear polarization resistance method and half-cell potential method during the 1 year. And measurements of the real steel loss give the conversion ratio of polarization resistance and corrosion rate; consequently, their results make the prediction equation of rust growth during any specified period. In case of using deicing salts, surface chloride contents that change with time are focused. The proposed methods are considered to be useful for prediction of remaining service life of the land concrete by steel corrosion.