LOCALIZED CATHODIC PROTECTION OF SIMULATED PRESTRESSED CONCRETE FILINGS IN SEAWATER

Corrosion-induced deterioration of prestressed concrete pilings in sea water has been established as the predominant failure mode for bridge substructures in coastal Florida waters. A technology involving locali zed impressed-current cathodic protection (CP) of the splash-zone regi on in association with conductive rubber anodes was developed to mitig ate this deterioration. A series of experiments involving cathodic pol arization of simulated prestressed concrete piling specimens partially immersed in seawater was performed. Variables included the concrete m ix design, specimen cross section, anode dimensions, and water level. An interactive aspect of CP-operating parameters in association with w ater level was identified as important if excessively negative potenti als and possible tendon embrittlement were to be avoided. The data wer e evaluated with regard to the interdependence between depolarization magnitude, potential, and concrete relative humidity. Results were rev iewed within the context of CP utility for prestressed concrete bridge piling.