PCA Strength Design of Anchorage to Concrete

Question

PCA Strength Design of Anchorage to Concrete

KLF (Structural)

(OP)

2 Oct 02 14:57

I'm using the PCA document "Strength Design of Anchorage to Concrete" EB080.01, 1999 to investigate capacity of embedded DECO adjustable anchor bolts (2" dia).

I calculate a pullout capacity, phi x Nn, which does not exceed ultimate force value, Nu from ACI-318. I then want to incorporate the capacity of steel rebar passing through the failure plane to recalculate the capacity. Doing this would allow for use of phi = 0.85 rather than 0.75, but I see no mention of reinforcing capacity in any of the clauses.

Am I missing somthing, or can I calculate a Tensile Capacity for the steel (via ACI-318) and subtract that from the ultimate load and then compare against Concrete strength? I do not have ACI-318-02, which as I understand, incorporates PCA EB080.01 as Appendix D.

Any thoughts or help on this topic would be appreciated.

MikeDB (Structural) · Answer 1 · 2002-12-12 11:53:22

I'm note sure I understand the question. I think the area of steel being refered to, is the area of bars being sheared in the concrete failure cone. For vertical anchor bolts, this would refer to horizontal rebar. The anchor bolt tension would then be compare to the shear strength of concrete and steel in the failure cone.

kevindav (Computer) · Answer 2 · 2003-02-04 17:59:38

KLF
I'm not completely sure what the question is either but try looking at pg a-11 and the conditions for psi 7 modification factor. psi 7 mod is used in concrete breakout strength in shear. In tension and shear as long supplementary reinforcement is provided(say a min of #4 bar within the projected failure area) I believe condition A or phi .85 is used. Also, Nn should be greater than or equal to Nu because it's the lowest design strength in all test modes.

Kevin

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PCA Strength Design of Anchorage to Concrete