Accelerated cyclic corrosion testing of structural steels and its application to assess steel bridge coatings

摘要

Purpose - The purpose of this study was to determine correlation between an accelerated cyclic corrosion test (S6-cycle test) specified in Japanese Industrial Standards K5621 and field exposure tests, and to open up applications of the accelerated tests in various regional environments. Design/methodology/approach - The S6-cycle corrosion test was carried out on structural steels for 30, 60, 90, 120 and 150 days and metal coating films for 100, 200 and 300 days. Comparing the weight loss of the steels with 1-, 3-, 5- and 9-year field exposure test data at 31 sites in Japan. Correlation of the S6-cycle tests to the field exposure tests was determined by acceleration coefficients. Findings - The correlation between the S6-cycle test and the field test on uncoated structural steels can be determined by acceleration coefficients based on flying salt amount. The coefficients were applicable for durability prediction of uncoated, zinc hot-dip galvanized and painted steels. Research limitations/implications - In determination of the accelerated coefficients, only the flying salt amount was considered. Others factors such as temperature and humidity will be considered in future work. Practical implications - Using the S6-cycle corrosion test and its accelerated coefficients, the thickness loss of uncoated structural steels and zinc hot-dip galvanizing is predictable in a short time. Corrosion degradation of coated steels is also predictable approximately. Originality/value - This paper contributes to open up the application of accelerated cyclic corrosion test to evaluating corrosion resistance of steel bridge members.