Abstract

The Kentucky Transportation Cabinet (KYTC) has maintenance oversight responsibilities for approximately 1,100 steel bridges; it also helps local governments and other entities with maintenance painting on other steel bridges. Because maintaining steel bridges is costly, Cabinet officials asked Kentucky Transportation Center (KTC) researchers to identify materials and methods that will prolong their service lives. Steel bridges are uniquely vulnerable to deterioration resulting from exposure to atmospheric conditions (e.g. moisture, ultraviolet rays) and chlorides, the latter due to the application of deicing materials. This study examines two strategies for extending service lives. First, it appraises a novel method of hot dip galvanization (HDG) and metallizing girders. Rather than dipping an entire girder in molten zinc at once, steel plates are immersed and then welded to form girders. In testing, all pieces that were coated using the method were adequately galvanized and metallized, thus establishing adequate protection against corrosion. The process can likely be scaled up and applied to larger steel pieces and girders. Next, researchers investigated whether carrying out an additional abrasive blast cleaning following power washing can reduce chloride levels. A second blast cleaning did not significantly lower chloride levels, and even led to slight increases, which may be the product of unreliable field testing or the use of recycled steel grit abrasive. Other methods of reducing chlorides should accordingly be investigated (e.g., specialized coating systems, high-performance coating systems).

Report Date

9-2020

Report Number

KTC-20-30/SPR17-551-1F

Digital Object Identifier

https://doi.org/10.13023/ktc.rr.2020.30

Notes

© 2021 University of Kentucky, Kentucky Transportation Center

Information may not be used, reproduced, or republished without KTC’s written consent.

The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Center, the Kentucky Transportation Cabinet, the United States Department of Transportation, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names or trade names is for identification purposes and should not be considered an endorsement.

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