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Post Tension Anchor Bolts

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I have a project needing post tensioned anchor bolts.  I know this has been discussed in the past year but the Archive search doesn’t seem to do well on recent posts.  

 

I have a detail from the machine equipment supplier showing the bolt encased in a tube.  About 2/3 of the way down there is a plate for the anchor rod to thread into.  The plate is located in a “bulge” in the tube to anchor the plate.  The tube allows the anchor bolt to be tensioned free from the bond of the concrete.

 

My question has to do with the design of the anchor bolt for pullout.  It seems to me the anchor can only take tension, no shear, since it floats in the tube.  The shear must be taken by the friction of the post tensioning force clamping the base plate to the concrete.  So when I check the anchor for pullout base on ACI Appendix “D” I only need to check it for tension.

 

Am I evaluating this condition correctly?

 

Also, I see in the archives that ASTM A193, B7 is recommended for the anchor bolts.  Since this is an old post. Is this still the correct material?  I was considering the 95 ksi yield strength of this material. 

 

Thanks.

 

 

Rich Lewis

Lewis Engineering