ACI 318-19 "additional" (?) ductility requirements for ASTM A615 and A706 Rebar

[cliff234]

ACI 318-19, Tables 20.2.1.3 (a). (b), and (c) list what seem to be additional ductility-related properties for reinforcing steel. Are these supplemental requirements in addition to what is already in ASTM 615 and ASTM 706? If they are not already in the ASTM specifications, then I would think the specifier (usually the EOR) would need to specifically reference these additional requirements when specifying the rebar on the contract documents. If these requirements are not currently in the ASTM specifications, why are they not? (What specifier would not want the rebar on their project to meet the additional ductility requirements?) I am concerned that they are not in the ASTM A615 and A706 specifications – because if they were, why would the ACI 318 Committee have felt the need to mandate them a second time in ACI 318-19, Chapter 20?

 

[canwesteng]

Firstly, because ACI does not write the ASTM specs so does not control what is in them, and secondly, you will probably meet these requirements just by specifying A706 instead of A615, but as the EOR you should confirm this.

 

[cliff234]

Firstly, because ACI does not write the ASTM specs so does not control what is in them, and secondly, you will probably meet these requirements just by specifying A706 instead of A615, but as the EOR you should confirm this.

canwesteng - Thank you for the response. The confusion I have is that two of the three ACI 318-19 tables that I referenced refer to ductility requirements for ASTM A706. The third table references ASTM A615 reinforcing steel. I am sensing that the purpose of these three tables is to point out additional ductility requirements that are not contained in the A615 and A706 specifications, and that engineers who merely reference A615 or A706 may not get the ductility mandated by the three tables in Chapter 20. (I attached a screenshot of those tables.) Why would the ACI 318 committee create three tables only to duplicate what is already in the A615 and A706 specifications? My concern is that if I specify only that the reinforcing steel be A615 or A706, then the fabricator might order that steel, but might not meet the additional ductility requirements specified in ACI 318-19, Chapter 20. My question is, do these three tables duplicate what is already in A615 and A706? I don't have copies of those two specifications.

 

[Agbsh]

Those tables/values were missing in older versions of ASTM A706-16 and A615-18, hence ACI added them. Newer versions elaborate on those limits, that why we do not see those tables in ACI 318-25, with one exception for Supp. S1 which is not mandatory for A706, unless purchaser ask for (related to earthquake resistant structures), ACI still asks to be added to specs and drawings.

 

[Agbsh]

Forget to mention, there are still some values in the ACI 318-25 appendices (as an option).

 

[cliff234]

Those tables/values were missing in older versions of ASTM A706-16 and A615-18, hence ACI added them. Newer versions elaborate on those limits, that why we do not see those tables in ACI 318-25, with one exception for Supp. S1 which is not mandatory for A706, unless purchaser ask for (related to earthquake resistant structures), ACI still asks to be added to specs and drawings.

Thank you Agbsh. You confirmed my concern. Just to be safe I'm going to specify ASTM A615-22 and A706-24 so the additional ductility requirements are included.

 

[BulbTheBuilder]

I didn't fully understand what was going on here, but I came across this document which I found helpful BULLETIN: ACI MODIFICATIONS TO REINFORCING STEEL SPECIFICATIONS . Bulletin 2.1.2 confirms your concern.