Design Memorandum

TO:                  All Design Section Staff

FROM:            Bijan Khaleghi
DATE:             September 26, 2006
SUBJECT:       ASTM A 706 Reinforcement Requirement

The following revisions are made to the use of reinforcement for bridge construction:

  • ASTM A 706 “Low Alloy Steel Deformed Bars for Concrete Reinforcement” shall be used for all cast-in-place concrete bridge reinforcement, including shafts and concrete piles, and for precast elements for bridge substructure. ASTM A 706 bars are more suitable for seismic applications, bar bending and welding.

  • AASHTO M 31 “Deformed Carbon Steel Bars for Concrete Reinforcement”, grade 60, or ASTM A 706 bars may be used for following categories:
    • Precast prestressed superstructure members
    • Traffic barriers except for “S” bars
    • Bridge approach slabs
    • Sidewalks
    • Standard Plan Retaining Walls, Noise Barrier walls and other walls
    • Other minor roadside structures

The above revision is applicable to all bridge projects with AD Dates on or after January 2, 2007.

Section 9-07.2 of the WSDOT Standard Specifications will be updated to reflect the above revision.


ASTM A 706 specifications were developed for seismic applications. Limits are placed on yield and tensile strengths. Also, chemistry is controlled to facilitate welding. ASTM A 706 is available in sizes from #4 to #18. Coils of deformed bar meeting ASTM A 706 requirements are available in sizes from #3 to #6. Availability of ASTM A 706 reinforcing has improved locally, with only a modest price increase over AASHTO M 31.

All reinforcing bars specified in the Bridge Plans Barlist are considered to be ASTM A 706 bars. All other reinforcing bars specified in separate barlist in bridge plans such as precast members, traffic barriers, sidewalks, and bridge approach slabs could be either AASHTO M 31 or ASTM A 706 Steel.

If you have any questions regarding these issues, please contact Nate Brown at 705-7219 or Bijan Khaleghi at 705-7181.

cc:   Mohammad Sheikhizadeh, Bridge Construction - 47354

       F. Posner, Bridge and Structures – 47340