SRCP Undertake Site Visit to Stockton Bridge Trial Piers ZLA Gives 400mv 24hr Decay
Stockton bridge was built in 1971 to replace the ferry service between Stockton and Newcastle in NSW, Australia.
When corrosion was identified the NSW Roads and Maritime Services undertook trials on the use of ZLA to provide cathodic protection on piers where corrosion was active but corrosion damage was not widespread.
The 24 hr decays were well in excess of 100mv required by Australian and ISO codes for true cathodic protection.
The trial installation is part of an assessment program of galvanic anodes for cathodic protection.
Cathodic protection is considered as the only permanent repair method of reinforcement corrosion.
Impressed current systems are expensive to install and maintain and the cost of repairing all NSW bridges that need protection using ICCP is not possible and hence they are using the much lower cost galvanic system to at least provide a holding repair.