Anchor Design: Concrete Breakout Code Comparison
Anchor Design: Concrete Breakout Code Comparison
(OP)
I'm checking anchors subjected to tension for concrete breakout, according to the 2004 Canadian concrete standard CSA A23.3-04. I believe the anchor design guidelines are almost identical to those outlined in ACI 318.
The question I have arose when my boss gave me his old 1984 code (CAN3-A23.3-M84) as a reference. The concrete breakout resistance that I calculated for the anchor group based on the 1984 code was almost 2x greater than the resistance calculated according to the 2004 code.
I've attached calculations from both codes for comparative purposes. I'm hoping someone who is familiar with the codes can shed some light on why there appears to be such a big descrepancy in the breakout resistance.
Thanks in advance.






RE: Anchor Design: Concrete Breakout Code Comparison
RE: Anchor Design: Concrete Breakout Code Comparison
I'm sure there is a better understanding of anchor failure mechanisms now than there was in the old codes. If these equations are more accurate, wouldn't any anchors designed according to the old codes be under-designed (theoretically)?
RE: Anchor Design: Concrete Breakout Code Comparison
Depends on your definition of better understanding. lol
But theoretically yes you are correct.
RE: Anchor Design: Concrete Breakout Code Comparison
You can also go to Hilti's website and download their Profis Anchor software. You can now design embed plates with studs! Very easy to use and fast.
As far as the old code being unconservative... the concrete has to crack first before it is uncracked :o/ If the concrete is not in tension then you're getting the uncracked capacity... Embed plates on the bottom of slabs is where I would be concerned. Basically tension zones.
www.anchorengineer.com
RE: Anchor Design: Concrete Breakout Code Comparison
RE: Anchor Design: Concrete Breakout Code Comparison
RE: Anchor Design: Concrete Breakout Code Comparison
www.anchorengineer.com
RE: Anchor Design: Concrete Breakout Code Comparison