"GREEN RUST", IRON SOLUBILITY AND THE ROLE OF CHLORIDE IN THE CORROSION OF STEEL AT HIGH PH

The solubility of iron, as well as nature of the solid corrosion products, influences greatly the kinetics and mechanism of reaction of steel embedded in cement or concrete. At high pH, ferric iron has a very low solubility, less than 1mM/l, and spinel, which passivates steel, is obtained as the solid corrosion product. However, at pH of approximately 13, low chloride ion concentrations are inimical to spinel formation; the solubility-limiting solid corrosion product is instead "green rust", a layer-structured hydrate containing both Fe2+ and Fe3+ and Cl-. In the range 10-15mM/l chloride, iron solubility at pH of approximately 13 increases abruptly from near zero to approximately 170-180mM/l. The enhanced solubility of iron, probably as an aqueous chlorocomplex, allows it to be transported. The resulting mobility with subsequent precipitation from the complex results in corrosion product being disseminated within the paste. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00088846
• Corporate Authors:

  Pergamon Press, Incorporated

  Headington Hill Hall
  Oxford OX30BW,    
• Authors:
  • SAGOE-CRENTSIL, K K
  • Glasser, F P
• Publication Date: 1993-7

Language

• English

Media Info

• Features: References;
• Pagination: p. 785-91
• Serial:
  • Cement and Concrete Research
  • Volume: 23
  • Issue Number: 4
  • Publisher: Elsevier
  • ISSN: 0008-8846
  • Serial URL: http://www.sciencedirect.com/science/journal/00088846

Subject/Index Terms

• TRT Terms: Chlorides; Corrosion; Material reinforcement; Reinforced concrete; Reinforcing materials; Steel
• ITRD Terms: 5252: Corrosion; 7314: Halide; 4794: Reinforced concrete; 3471: Reinforcement (in mater); 4542: Steel
• Subject Areas: Construction;

Filing Info

• Accession Number: 00642173
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Feb 15 1994 12:00AM