Hooked horizontal bars in special shear wall
Hooked horizontal bars in special shear wall
(OP)
I'm trying to determine the reasoning behind why we're required to hook the horizontal bars around the vertical bars in special reinforced shear walls. I've seen this requirement both in ACI 318 and ACI 530 (concrete and cmu) although ACI 318 only requires it if your design shear in the wall is greater than the Acv*lambda*sqrt(fc) and you don't have boundary elements. I'm asking because I have a cmu building in California under construction and the Contractor didn't measure correctly. When he poured the foundation he placed the vertical dowels too close to the inside edge of the cmu block and he can't get the horizontal hook around it. I'm trying to determine a fix and would like to know the reasoning behind the hook to decide on the best solution. Thanks for the help.






RE: Hooked horizontal bars in special shear wall
As a fix, I'd recommend throwing an extra vertical bar in at the end of the wall just for the purpose of anchoring the horizontal bar hooks. I don't believe that there would be any justification for needing a matching footing dowel for the additional bar.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Hooked horizontal bars in special shear wall
For my project, I was going to have the Contractor create a boundary element with #3 ties (it's a 12" cmu block so there's plenty of space) but it seems your solution might be easier/cheaper. Thanks!
RE: Hooked horizontal bars in special shear wall
The hooking of the horizontal reinforcing properly develops loads into horizontal reinforcing and provides additional strength to jamb from the loading and unloading. Did you design your wall as part of chapter 3 of ACI 530? Adding a boundary element at the end of a wall has more of an impact than just adding ties.
RE: Hooked horizontal bars in special shear wall