INTERIOR CORROSION OF STRUCTURAL STEEL CLOSED SECTIONS

A SURVEY OF LIGHT POLES, WATER-TANK STANCHIONS, ORTHOTROPIC DECK BRIDGES, MARINE TUBULAR CATWALKS, DAVITS AND WELDED STEEL COLUMNS STRONGLY SUGGESTS, CONTRARY TO SOME BELIEFS, THAT INTERIOR SURFACES OF CLOSED STEEL SECTIONS RUST BUT LITTLE IN THE ATMOSPHERE, EVEN WHEN NOT FULLY SEALED. ONLY LIGHT RUSTING OCCURS BECAUSE AMOUNTS OF OXYGEN AND WATER IN ENTRAPPED AIR ARE LIMITED AND CONDENSATION NECESSARY FOR RUSTING IS INFREQUENT. COMPUTATIONS BASED ON THE OXIDATION REACTION TAKNG INTO ACCOUNT INSIDE SURFACE, VOLUME OF ENTRAPPED AIR, RELATIVE TYPE III CEMENT, WAS FOUND TO BE THE ONLY CONCRETE TO EXCEED THICKNESS DUE TO SUCH RUSTING IS NEGLIGIBLE. USE OF CLOSED STEEL SECTIONS FOR STRUCTURAL MEMBERS IN BRIDGES AND BUILDINGS IS THEREFORE FEASIBLE WITH THE KNOWLEDGE THAT NO STRENGTH LOSS WILL OCCUR FROM INSIDE OXIDATION. THE CONCEPT APPLIES WHETHER THE CLOSED STEEL SECTION IS, FOR EXAMPLE, OF RELATIVELY SMALL TUBULAR CONFIGURATION OR OF LARGE BOX SHAPE. THE FACT THAT INTERIOR SURFACES OF CLOSED STEEL SECTIONS NEED NOT BE PAINTED TO PREVENT OXIDATION WILL RESULT IN SUBSTANTIAL REDUCTION OF MAINTENANCE COSTS AND ELIMINATE THE NEED FOR MANHOLES WITH REMOVABLE COVERS WHERE THIS HAS BEEN THE PRACTICE. AN ESTIMATED POTENTIAL SAVINGS IN MAINTENANCE COSTS UP TO 45% IS GIVEN WHERE THE USE OF CLOSED BOX SECTIONS IN BRIDGES ELIMINATED THE NEED FOR PAINTING SECTION INTERIORS. /AISI/

  • Supplemental Notes:
    • Tech Rept M-2, 61 PP, FIGS, TABS, PHOTS, REFS
  • Corporate Authors:

    American Iron and Steel Institute

    1101 17th Street, NW, Suite 1300
    Washington, DC  USA  20036-4700
  • Authors:
    • Bloss, D R
  • Publication Date: 1970-2

Subject/Index Terms

Filing Info

  • Accession Number: 00217067
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 18 1971 12:00AM