rebar / all-thread vs.deformed ?? 2

[boffintech]

I'm looking at a stack of rebar and the tag reads A615 grade-75 all-thread rebar. But in reading the definition of "deformations" in A615 I can't tell if these threads meet the given criteria. I think these are the bars usually used in tension piles. We're building a compression member. At any rate, are there any issues with substituting all-tread rebar for the normal A615 grade-60 deformed rebar?

 

[bridgebuster]

I think you have to take some measurements of your thread bar, based on Table 1 of the specification.

Does the root diameter & perimeter meet or exceed the requirements?

If we consider a thread as a deformation, you would meet the maximum average spacing for deformations. However, does the thread height meet the minimum average height?

My gut feeling is that the thread bar should work.

 

[BAretired]

I don't believe that a threaded bar will provide equivalent bond to a deformed bar, but it would certainly be better than a smooth bar.

BA

 

[PMR06]

Are you the inspector for this? If so, this would be something worth passing onto the EOR for review and/or approval.

 

[apsix]

I would ask for justification for the substitution.
Ask for documentation showing that the bar is equivalent.

It's not your job to show/determine that it's equivalent.

 

[dirtydude]

Reading through a couple of manufacturer's literature, it states that their GR75 all thread bar conforms to ASTM A615. That was Williams and Dywidag.

 

[boffintech]

Yes, am the inspector.

It appears that the justification for the substitution is convenience.

Also, it appears to be a Williams bar.

 

[TXStructural]

If the threaded bar conforms to ASTM A615 the threads meet the requirements for deformations. (This would not be the case for typical "all-thread", which has cut, machine threads, rather than large forged/rolled threads.) The forged/rolled threadbar from any reputable mill will meet the requirements for deformations.

Typically, the deformation pattern varies by mill and size, and may vary from line to line in a single mill. Spiral threadbar is just another deformation pattern.

John Turner CSP PE
CRSI Greater Southwestern Regional Manager