Torsion Reinforcement Using WWR Cage

[TehMightyEngineer]

I have a small strip of a precast concrete piece that is very lightly loaded in service and is being reinforced with small mats of WWR. Essentially it's acting as a beam connecting two walls. However, during stripping, transport, and placement there's a genuine concern that someone will put this beam into torsion.

To resist this I'm hoping to use leftover pieces of the WWR bent into a cage inside the beam as specified in ACI 318 11.5.4.1(b). This should be a cheap and easy way for the precaster to reinforce this without spending a lot of extra time bending and placing stirrups.

However, because I'm using a WWR cage I don't see how I can easily provide the 135-degree standard hook required by 11.5.4.2(a). I don't really have anything meeting the alternative requirements of 11.5.4.2(b) to resist spalling around the anchorage.

Does anyone see a way around this? Seems that this grossly limits the use of a WWR cage in place of stirrups to only members with slabs, flanges, or similar to resist spalling as required by 11.5.4.2(b)


Maine Professional and Structural Engineer. www.fepc.us

 

[TehMightyEngineer]

Revised to use the larger WWR mat and put the longitudinal bars inside the transverse wires.

I just can't see this being any weaker than standard hooked stirrups.

Maine Professional and Structural Engineer. www.fepc.us

 

[KootK]

I agree with your reasoning here. If you're worried about code compliance, I suppose that you could fully develop the wire on each side of the bend.

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.

 

[TehMightyEngineer]

Not worried about code compliance, this is 100% so that they can strip the forms, flip the piece, and put it on a truck without breaking it. My only concern was that the code intent was being met.

Maine Professional and Structural Engineer.

http://www.fepc.us