Development length of nonstandard hooks
Development length of nonstandard hooks
(OP)
I need to develop a #5 epoxy coated rebar from a bridge parapet into an 8" slab. The bottom clearance is 1". Therefore, the hook is only embedded 7" into the slab. Can I achieve full development by extending the tail of the #5 bar?






RE: Development length of nonstandard hooks
I cannot see how anyone could argue you're wrong to develop the bar with a full development length after the hook.
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
I would expect to see some research on this topic but cannot find any research mixing hooked and straight development length.
ULS?
RE: Development length of nonstandard hooks
Sorry, it is a tenant of most engineering outside the USA. I take it you are in an American ASD or LRFD jurisdiction?
RE: Development length of nonstandard hooks
There are code provisions for calculating the capacity of hooked anchor bolts in tension...I would go that route and see if you can get the capacity you need with that. I'm not sure how effective the straight tail part of the rebar would be beyond a certain distance from the bend...my gut feeling is that the concrete would crush inside the bend before the straight section became effective. If you post a cross-section of the slab and parapet you may get more responses/suggestions.
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
JAE, does ACI spell that out explicitly in the code or commentary? Would you send me the reference please? I have looked through ACI 318-08 12.5 but have not seen that stated explicitly.
I am questioning the P502E bar in the Attachment.
RE: Development length of nonstandard hooks
BUT, I would think that even if not developped as a hooked bar, having a full extension past this would enable you to fully develop the bar. Doesn't matter if the concrete crushes, if the result is that the bar continues to withdraw slowly without failing.
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
It looks like a traffic barrier. You're looking for it to reach it's design limit once. After that, it probably needs to be repaired or replaced.
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
However, it was taught to me in school and I found a reference in my Wang & Salmon text book that stated:
"With 90 degree hooks particularly, designers have often assumed that satisfactory anchorage is obtained by adding length to the end of the bar in excess of 12 bar diameters required as part of the hook. This is an unsatisfactory practice."
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
RE: Development length of nonstandard hooks
A stirrup is a bar in tension so I see no difference from a mechanics perspective.
RE: Development length of nonstandard hooks
rapt, I am not familiar with your code references. Do you have a minimum required radius to consider the additional extension for #5 bar?
slickdeals, I don't think I can design it as a corbel since the height of the parapet is large compared to the base of the parapet.
RE: Development length of nonstandard hooks
http://www.structuremag.org/article.aspx?articleID...