Session: Next-Generation Coatings: Predictive Strategies for Service Life, Durability, and Sustainable Performance
Shielding Effects of Coatings in Cathodic Protection Systems: Experimental Techniques, Observations, and Case Histories (C2026-00385)
Tuesday, March 17, 2026
3:00 PM - 3:30 PM Central
Location: 372 BC
Earn .5 PDH
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mehrooz zamanzadeh, Anil Kumar Chikkam, Peyman Taheri, George Bayer, Hena Rehman , Austin Kuechle, Keng Yap
This study evaluates the shielding behavior of various below-ground pipeline-grade coatings—both historical and current—to understand how their performance differs under cathodic protection (CP) conditions. The effectiveness of CP in preventing external corrosion on buried pipelines can be significantly reduced when coatings inhibit CP current from reaching the steel surface. Disbonded coatings may still adhere locally while trapping corrosive species and obstructing current flow, increasing the risk of localized corrosion. A systematic laboratory testing protocol was developed to assess whether selected coatings exhibit shielding behavior. The procedure includes sample preparation, electrochemical impedance spectroscopy (EIS), and impressed current CP testing in controlled electrolyte environments. Coating disbondment morphology, interface chemistry, and electrical resistance are characterized to simulate field-representative scenarios. CP current is applied across both intact and disbonded regions to evaluate its distribution and the polarization response of the underlying steel. Findings from this study provide valuable insights for coating selection, integrity assessments, and CP system design in both new and aging pipeline systems.
