PHYSICAL MODEL FOR STEEL CORROSION IN CONCRETE SEA STRUCTURES--THEORY

A physical-mathematical model is developed for concrete exposed to sea water. The model describes: (1) Diffusion of oxygen, chloride ions, and pore water through the concrete cover of reinforcement; (2) ferrous hydroxide near steel surface; (3) the depassivation of steel due to critical chloride ion concentration; (4) the cathodic and anodic electric potentials depending on oxygen and ferrous hydroxide concentrations according to Nernst equation; (5) the poloarization of electrodes due to changes in concentration of oxygen and ferrous hydroxide; (6) the flow of electric current through the electrolyte in pores of concrete; (7) the mass sinks or sources of oxygen, ferrous hydroxide, and hydrated red rust electrodes, based on Faraday law; and (8) the rust production rate, based on reaction kinetics. To enable calculations, numerical values of all coefficients are indicated. The theory is completed by formulating the problem as an initial-boundary value problem. /Author/

• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Bazant, Z P
• Publication Date: 1979-6

Media Info

• Features: Figures; References;
• Pagination: p. 1137-53
• Serial:
  • Journal of the Structural Division
  • Volume: 105
  • Issue Number: ST6
  • Publisher: American Society of Civil Engineers

Subject/Index Terms

• TRT Terms: Chlorides; Concrete structures; Corrosion; Electrodes; Electrolytes; Hydroxides; Material reinforcement; Mathematical models; Oxygen; Physical properties; Pore water; Pores; Slag coarse aggregates
• Uncontrolled Terms: Pores
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00196160
• Record Type: Publication
• Report/Paper Numbers: ASCE 14651 Proceeding
• Files: TRIS
• Created Date: Sep 15 1979 12:00AM