INITIAL ANALYSIS OF CATHODIC PROTECTION SYSTEMS ON U.S. 87 RAILROAD OVERPASS BRIDGE - BIG SPRING, TEXAS. INTERIM REPORT

Five individual cathodic protection systems were installed on the U.S. 87 Missouri-Pacific Railroad overpass structure in Big Spring, Texas. The cathodic protection systems were installed in October 1988 as a demonstration project to compare the various systems. Three distributed anode types were used to protect the bridge deck: (1) titanium mesh; (2) conductive polymer; and (3) carbon strand. A hot-sprayed zinc conductive coating anode was applied to sidewalks and a median on the bridge deck, and a conductive paint anode was applied to a bridge bent. Performance data have been collected for each system since installation. The titanium mesh anode continues to function while the conductive polymer anode has failed and the carbon strand anode exhibits instability. The hot-sprayed zinc anode system failed early in the study and the conductive paint anode system shows signs of failure.