A PRACTICAL APPROACH TO COUNTERACTING CORROSION OF BRIDGE STRUCTURES

THE CAUSES OF CORROSION OF VARIOUS BRIDGE MEMBERS ARE REVIEWED AND PROCEDURES FOR THE DEVELOPMENT OF A CORROSION CONTROL PROGRAM ARE RECOMMENDED. THE ELECTROCHEMICAL CORROSION PROCESS IS CAUSED BY GALVANIC ACTION, AND BY THE DISCHARGE OF STRAY DIRECT CURRENT FROM THE SURFACE OF THE BURIED METAL. STEEL "H" PILES AND PIPE-TYPE PILES DETERIORATE BECAUSE OF CORROSION. CONCRETE JACKETS CAUSE ACCELERATED CORROSION WHERE BOTH CONCRETE AND WATER ARE IN CONTRACT WITH STEEL. THE CONCRETE IN BRIDGE FOUNDATIONS AS WELL AS BULKHEADS AND SHEET STEEL PILES ARE GREATLY AFFECTED BY CORROSION. THE USE OF SOME PROTECTIVE SYSTEMS ARE OUTLINED. A SURVEY OF EXISTING BRIDGES WILL REVEAL THE EXTENT OF CORROSION AND SUGGEST THE BEST MEANS OF CONTROLLING IT. THE USE OF COATINGS, CATHODIC PROTECTION, GOOD SPECIFICATIONS AND THE PROPER SELECTION OF MATERIALS FOR BRIDGE CONSTRUCTION, WILL CONTROL THE PROBLEM OF CORROSION. AN ADEQUATE DESIGN USING SELECTED MATERIALS SHOULD BE THE INITIAL STEP. COATINGS SUCH AS ASPHALT, COAL TAR AND EPOXIES HAVE PROVED USEFUL IN DETERRING CORROSION. CATHODIC PROTECTION BY GALVANIC OR IMPRESSED CURRENT SYSTEMS IS USEFUL IN CONTROLLING CORROSION OF PILES. LIMITATIONS TO THE USE OF CONCRETE JACKETS ARE DISCUSSED. THE COST FACTOR GOVERNS THE SELECTION OF THE MATERIALS AND METHODS USED. CORROSION CONTROL AWARENESS DURING THE DESIGN STAGES, REPRESENTS A SUBSTANTIAL SAVING IN OPERATION AND MAINTENANCE COSTS. INSPECTION METHODS USED TO DETECT THE PRESENCE OF BRIDGE FOUNDATION CORROSION ARE OUTLINED. VISUAL INSPECTION USING DIVERS AND TELEVISION CAMERAS HAVE PROVEN SATISFACTORY. SURVEYS BY CORROSION ENGINEERS INVOLVING NON-DESTRUCTIVE ELECTRICAL TESTS IS CONSIDERED ECONOMICAL. CONCRETE BRIDGE DECK SPALLING IS DESCRIBED AND THE USE OF COATINGS (BOTH METALLIC AND DIELECTRIC) FOR ITS PREVENTION IS DISCUSSED. THE PROHIBITION OF THE INCLUSION OF CHLORIDES IN CONCRETE IS ONE OF THE MOST EFFECTIVE OF CONTROL MEASURES. THE USE OF CORROSION RESISTANT NON-METALLIC MATERIALS AND WEATHERING STEEL, AND CAREFUL INSPECTION OF PINS AND OTHER FASTENERS IS ADVOCATED. A TRAINING PROGRAM FOR CORROSION CONTROL PERSONNEL IS RECOMMENDED.

Media Info

  • Features: Figures; Photos;
  • Pagination: 4 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00217358
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 5 1974 12:00AM