CORROSION PROTECTION OF PRESTRESSED CONCRETE PIPES

THE THEORY CONTROLLING THE PRESERVATION OF STEEL IN CONCRETE BY THE GENERATION OF A PASSIVATING POTENTIAL IS SUMMARIZED. PASSIVATION DECREASES OR DISAPPEARS IF THE CONCRETE IS GENERALLY OR LOCALLY POROUS SO THAT MAXIMUM UNIFORMITY AND IMPERMEABILITY IS OBLIGATORY FOR PRESTRESSED CONCRETE PIPES. LONG PIPELINES SHOULD COMPRISE UNITS OF THE SAME TYPE, OTHERWISE INSULATING JOINTS SHOULD BE PROVIDED BETWEEN UNITS OF DIFFERENT NATURE. THE STEELS USED SHOULD BE NEITHER BRITTLE NOR SENSITIVE TO CORROSION, WHILE THE PROJECTED ROUTE FOLLOWED BY THE LINE SHOULD BE INITIALLY EXPLORED TO REVEAL THE AGGRESSIVE NATURE OF SOILS SO THAT PRECAUTIONS CAN BE TAKEN IN DANGEROUS AREAS. CATHODIC PROTECTION OF PRESTRESSED CONCRETE PIPES IS USEFUL WHEN PARTLY CORRODED PIPES SHOW SIGNS OF FATIGUE OR WHERE NEW PIPELINES CROSS AREAS OF LOW ELECTRICAL RESISTIVITY AND PIPE POTENTIALS TREND TOWARDS NEGATIVE VALUES. WITH HIGH- GRADE CONCRETE THE NECESSARY CURRENT FOR CATHODIC PROTECTION NEED ONLY BE 0.4 MA/M SQ, BUT 1 MINUS 1.5 MA/M SQ MAY BE REQUIRED FOR LESS COMPACT CONCRETE. THESE PRACTICAL MEASURES ARE BASED MAINLY ON OBSERVED FAILURES OF PRESTRESSED CONCRETE PIPES. /AUTHOR/

  • Supplemental Notes:
    • Vol 12, No 3, PP 7-13
  • Corporate Authors:

    Corrosion Technology

    ,    
  • Authors:
    • Franquin, J
  • Publication Date: 1965

Subject/Index Terms

Filing Info

  • Accession Number: 00212364
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 12 1994 12:00AM