The rail bridge over the Silvermine River is a 115-year old historical structure situated in a sensitive estuarine environment. The bridge exhibited advanced deterioration, evidenced by large cracks, spalled and delaminated portions of the bottom concrete cover and intense corrosion of the embedded reinforcement due to the advanced chloride-induced corrosion mechanism. The bridge has a unique reinforcement configuration that further complicated and reduced the available repair options. Cathodic protection was selected as the most suitable repair option to reinstate the rail bridge after considering the technical, environmental, historical and financial factors. The cathodic protection system was designed in accordance with international best practice guidelines to achieve full protection of the reinforcement and a minimum design life of twenty-five years. A two-year monitoring period using standard international verification techniques to ensure adequate functioning cathodic protection follows the commissioning phase.
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