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RE: Anchor Bolts Revisited

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Title: RE: Anchor Bolts Revisited

>How well do the hooked anchor bolts perform compared to the straight anchor
>bolts with nuts for tension loading?

I know this may fly in the face of common practice, but I personally would not recommend that hooked rods be used to resist calculated tensile forces, paricularly if the hook accounts for the majority of the strength. If all is perfect, a hooked rod can provide anchorage as calculated. But it's pretty likely that the oil from threading will remain on the rod. I suspect this is why there have been cases of failure of hooked rods that just pull the hook (semi-straightened) through the concrete (like a snake around the bend).

>I am reviewing some shop drawings for some mast arm structures.  These
>typically have drilled shaft foundations and historically the fabricators
>have used very long anchor bolts (7'-0" long anchor bolts are not uncommon)
>with a "J-Hook" at the bottom.

>Perhaps one of the fabricators can answer this one:  Are the long anchor
>bolts provided for convenience (since the fabricator typically does not
>design the foundation and therefore, does not know what kind of reinforcing,
>etc. is provided for the load transfer)?

Although I'd always encourage a fabricator to provide value engineering input, I don't think the fabricator is the appropriate party to select and/or provide the design of anchor rods. Perhaps that wasn't your intent, but in any case, anchorage devices should be designed and specified by the engineer of record.

Charlie