A question about ACI 318 appendix D

[woaiwocahng]

Hi folks
In D.3.3.4.3, it says "For single anchors, the concrete-governed strength shall be greater than the steel strength of the anchor". I think this is hard to achieve considering that the steel has a much higher strength than concrete. So, I am very confused with this statement. Am I misunderstanding?

 

[hokie66]

Read it again. "Concrete-governed strength" means just what it says. The steel has to fail, not pull out of the concrete.

 

[BUGGAR]

It's strength, not stress. The concrete must not fail in pullout or any of the thousand other concrete failure modes they cover because this is a non-ductile failure. The weak link has to be in the baseplate or column above. That is your challenge. Make the steel just strong enough, and the concrete (failure modes) stronger.

Bob

 

[KootK]

In summary OP: you've interpreted the clause correctly and it will indeed be quite challenging to satisfy.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.