PREDICTING THE DURABILITY OF MARINE STRUCTURES IN THE NETHERLANDS: ASSESSING THE MIGRATION COEFFICIENT

摘要

For service life design of marine structures, predicting the chloride penetration is of utmost importance. Since the resistance of concrete against chloride penetration increases with age, it is common practice to include an age dependent chloride transport model in the service life calculations. However, one of the most used ageing models predicts that ultimately the chloride migration becomes zero, contrary to what is observed in practice.rnOn the basis of chloride migration tests on laboratory concrete up to an age of 3 years, an adapted ageing model has been developed with a nonzero ultimate migration coefficient. Since 3 years is not a very long time as compared to the often demanded 100 or 200 years service life of modern marine structures, virgin concrete samples have been drilled from existing marine structures in the Netherlands with an age between 16 to 41 years for further validating the model.rnIt is shown that the adapted age model models the field data very well. The standard deviation of the field data is comparable with those of the LAB data. It gives confidence that the service life design, on the basis of the LAB data, will give a very realistic prognosis of the service life with respect to corrosion initiation.