Effects of Multiple Damage and Heat Straightening Repairs on Steel Beams

Experimental investigations were conducted to evaluate the effects of multiple damage-heat straightening repair cycles, i.e., multiple cycles of damage followed by heat straightening repair on the structural properties and fracture toughness of large-scale steel beams. Six W24x76 equivalent beam specimens made from A7, A588, and A36 steel (two of each steel type) were tested by subjecting each of them to three cycles of damage-heat straightening repair. The testing approach was based on the heat straightening procedures used by the Michigan DOT statewide bridge crew. The beam specimens were damaged statically in weak axis bending, and repaired by heat straightening using several partial (half) depth Vee heats distributed along the length of the flanges. Material specimens for uniaxial tension and fracture toughness testing were machined from the damaged-repaired flanges and tested according to ASTM standards. The experimental investigations and material test results indicate that multiple damage-repair cycles do not have a significant influence on the elastic modulus, yield and ultimate stress, hardness, and ductility of steels. However, after three damage-repair cycles, the fracture toughness of A7 and A36 steels repaired with maximum heating temperature (Tmax)=650oC becomes low. The fracture toughness of A588 steel repaired with Tmaz=650oC and A36 steel repaired with T¬max=760oC remained high and comparable to the undamaged fracture toughness. In all cases, the structural properties varied across the depth of the damaged-repaired beam flange, i.e., material specimens closer to the flange-web junction had significantly lower fracture toughness and ductility, and higher yield and ultimate strength.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Varma, Amit Hariom
  • Kowalkowski, Keith Joseph
• Conference:
  • Transportation Research Board 85th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2006-1-22 to 2006-1-26
• Date: 2006

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; References; Tables;
• Pagination: 28p
• Monograph Title: TRB 85th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

• TRT Terms: Beams; Flanges; Fracture properties; Heat affected zone; Repairing; Steel; Straightening
• Uncontrolled Terms: Heat straightening
• Subject Areas: Bridges and other structures; Highways; Materials; I34: Steels and Metals;

Filing Info

• Accession Number: 01024854
• Record Type: Publication
• Report/Paper Numbers: 06-1863
• Files: BTRIS, TRIS, TRB
• Created Date: May 31 2006 7:55AM