The fracture of deformed reinforcing bars at designed bends is discussed with the aid of a typical case history. These fractures are shown to be by cleavage as a result of strain age embrittlement, usually associated with stress concentrations (notches) formed by the deformations (protrusions) on the bend inner radius surface. The mechanism of strain ageing in low carbon structural steels is outlined, and a new structural steel, resistant to strain age embrittlement, is recommended. Some of the improved properties of this steel over the existing grade 275 structural steel are outlined. The mechanism of notch formation on bend inner radii surfaces is discussed, and recommendations for the minimum radii to be used for bends in reinforcing bar are made. Other methods of avoiding this type of failure are suggested. (A). /TRRL/

  • Availability:
  • Corporate Authors:

    Technical Publications Limited

    C.P.O. 3047
    Wellington,   New Zealand 
  • Authors:
    • Erasmus, L A
    • Pussegoda, L N
  • Publication Date: 1977-8


  • English

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 178-183
  • Serial:
    • Volume: 32
    • Issue Number: 8
    • Publisher: Institution of Professional Engineers New Zealand
    • ISSN: 0028-808X

Subject/Index Terms

Filing Info

  • Accession Number: 00170322
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jun 28 1978 12:00AM