when You build Your ICF walls what rebar grade do You use and where
Horizontal rebar Grade 40 or 60
Vertical rebar Grade 40 or 60

We almost always use grade 60. The number 4 is the same price in either grade for me. But use what your engineering says. If you are useing 2006 irc you can use either, the spacing may vary.

As previously stated, either grade can be used; although, grade 60 is generally preferred if you can get it for close to the same price as grade 40 since it is ~50% stronger.

Download and study the HUD Prescriptive Method for ICF construction 2nd edition for more details.

www.huduser.org/Publications/PDF/icf_2ed.pdf

I would avoid grade 40 steel entirely. As arkie points out grade 40 is substantially weaker than grade 60. Also, i've seen some grade 40 that is too brittle to be considered acceptable. Use Grade 60 only.

ICFconstruction is wrong. :)


IRC 2006 R611.6.2 Reinforcing steel. Reinforcing steel shall
meet the requirements of ASTMA615, A706, orA996.
Except in Seismic Design Categories D0, D1 and D2, the
minimum yield strength of reinforcing steel shall be
40,000 psi (Grade 40) (276 MPa). In Seismic Design
Categories D0, D1 and D2, reinforcing steel shall meet the
requirements of ASTM A 706 for low-alloy steel with a
minimum yield strength of 60,000 psi (Grade 60) (414
Mpa).

Posted By Baldwin2012 on 03 Feb 2010 07:00 PM
ICFconstruction is wrong. :)


IRC 2006 R611.6.2 Reinforcing steel. Reinforcing steel shall
meet the requirements of ASTMA615, A706, orA996.
Except in Seismic Design Categories D0, D1 and D2, the
minimum yield strength of reinforcing steel shall be
40,000 psi (Grade 40) (276 MPa). In Seismic Design
Categories D0, D1 and D2, reinforcing steel shall meet the
requirements of ASTM A 706 for low-alloy steel with a
minimum yield strength of 60,000 psi (Grade 60) (414
Mpa).

Although this is not the section I was remembering, R611.6.2 does not contradict what I said.

What I was referring to can be found as notes to the Vertical Wall Reinforcement tables, such as R404.4(1).

"This table is based on concrete with a minimum specified concrete strength of 2500 psi, reinforcing steel with a minimum yield strength of 40,000 psi. When reinforcing steel with a minimum yield strength of 60,000 psi is used, the spacing of the reinforcement shall be increased to 1.5 times the spacing value in the table but in no case greater than 48 inches on center"

Hmmm yeah. I think you are right.... it all depends how you look at it... I think you gotta be careful which one you use.

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By the way some of you might be wondering what grade 40 or 60 really means.
It means that if you have a grade 60 #9 bar (which is exactly 1 square inch in cross section area) it will hold a maximum of 60,000 pounds without any permanent deformation. Applying more weight would permanently elongate and  break the bar shortly after. 
so a #4 bar grade 60 (which is 0.2 square inches cross section) will hold a maximum of (0.2*60000)=12,000 lb...

 

only grade 60 is supposed to be used for bent bars

Grade 60 vs. grade 40 may be a moot issue. When I was building my house I was told by someone, I don't recall if it was my concrete contractor, a concrete contractor acquaintance, or the concrete construction supply house guys, that when it comes to #4, and maybe even #5 rebar, that grade 40 is pretty much non-existent. The cost to make grade 60 is very little, if any more, than grade 40 so that's all the mills put out. Grade 40 bar is downrated grade 60 that doesn't quite meet the specs for grade 60.

Anyone able to confirm if this is in fact the case?

rebar info:

http://www.sizes.com/materls/rebar.htm