Are ASTM F1554 Grade 55 anchor rods > 2” in diameter a ‘ductile steel element’ per ACI 318-05 Appendix D.1?
According to ACI 318-05 Appendix D.1, a “Ductile Steel Element” is an element with a tensile test elongation of at least 14 percent and reduction in area of at least 30 percent. The minimum elongation percentage for any diameter of F1554 Grade 55 anchor rod is 21% and the minimum reduction of area percentage is 30%. Therefore, any diameter of Grade 55 anchor rod would meet or exceed the ACI requirement for a “Ductile Steel Element”. We can Refer to our ASTM F1554 Summary Page for complete mechanical requirements for the F1554 specification.
Hi Greg. Very informative explanation of Grade 55 anchor bolt ductility. In looking through the past versions of ASTM F1554, it appears for versions prior to F1554-15 the minimum reduction of area varied by diameter as you describe above. However, starting with F1554-15 it appears Table 3 specifies a minimum reduction of area of 30% for all diameters of Grade 55 bolts. Do you know if Grade 55 bolts with diameter greater than 2″ are now available that meet the reduction of area criteria of F1554-15 or F1554-17? Also, based on your description above and the specs in Table 3 of F1554, it appears all Grade 105 bolts would meet the ductility requirements of ACI 318. Could you please confirm this for Grade 105? Thanks!
@Kyle- We revised the ductility requirements of F1554 in 2015 in order to better align with ACI 318. Large diameter Grade 55 did not have any problem meeting the 30% minimum, so we revised the standard to make the minimum 30% regardless of diameter. Even before this change most larger material that we studied had RA% in excess of 30%. Grade 105 could theoretically fall below the minimum 14% elongation that ACI 318 requires when tested as bar (12% min in 8″ gage length). However, G105 is usually tested in a 2″ gage length where the minimum is 14%, the same as required as ACI 318.