Concrete beam at face of column

[Budding_SE]

I am trying to create a corbel condition at the face of the column. My vertical load is approx. 200 kips and no horizontal load.
What do you guys think? Can i use greater stirrups than #5. I know they hard to bend but can they still do it. This might occur at approx. 10 conditions on the whole job so not a lot.

 

[dhengr]

Budding_SE:
The corbel could go below the bottom of the 24”x36” beam by a foot or so and it could also extend the column width of 52” by a foot or so on each side to 76” +/-. In effect, you are building a three sided column capital, to allow more space for longitudinal rebars and ties, and greater shear cap’y.

 

[Budding_SE]

Due to architectural constraints, I cannot do that. I column capital cannot happen cos it conflicts with the stairs. Just to clarify, i am kind of creating a box beam with stirrups holding everything together if that makes sense.

 

[JAE]

Some codes (ACI) require corbels to have a minimum horizontal load applied.

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[jayrod12]

Some codes (ACI) require corbels to have a minimum horizontal load applied.

CSA does as well, but that's not really surprising since the two are extremely similar.

 

[KootK]

1) I see a possible need to consider the horizontal load mentioned by JAE in the direction parallel to the suspended beam, but not perpendicular to it. No doubt we're all thinking the same thing here.

2) It's a shame that dhengr's underside corbel isn't a viable option. I would like that very much for the reason that I'll mention next.

3) In my opinion, the main thing that your detail lacks is the acknowledgement of the fact that your load will be delivered by a diagonal compression strut to the bottom of the thing that you'll be calling a corbel. As I see it, you'll need to drag that load up to the top with hanger steel etc before you'll have any chance of calling that a bonafide corbel situation.

4) I love shear friction as much as the next gal but man, oh man, would I ever like to see a shear key into the column. Your dealing with a load there equivalent to about 85 Toyota Corollas.

5) What is the construction sequence here? Beam and column poured at the same time somehow? Column first wit ties penetrating the formwork?

6) For shear friction, you generally want well distributed reinforcement. I'd be inclined to have a forest of ties in there.

7) As far as using larger bars goes, I think that it's possible but you'll want to think it through very carefully. Firstly, bars larger than #5 cannot be assumed to be developed as soon as they hook past a transverse bar. I'd personally not want to give up that marvelous feature. Secondly, you'll want to detail it accurately to get a sense of the real geometry. On, say, a #8 bar, you'll be in 6" from the outside face of the 24" wide beam before you hit the point of bar tangency and can even think about dumping load into the system from the hanger bars that you'll need.

 

[JAE]

If that beam is taking vertical load from something that is attached to another part of the structure, I'd still want to put a nominal horizontal load on it.
If the beam supports lateral wind loads from the wall in this beam-column plane, I'd also want to include a horizontal load.

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[KootK]

If that beam is taking vertical load from something that is attached to another part of the structure, I'd still want to put a nominal horizontal load on it.

Right, but that nominal load would be directed along the axis of the member tying in and that direction only, right? My understanding was that the horizontal load was primarily intended to reflect loads coming in as a result of thermal, shrinkage, and creep loads in the supported member.

No argument on the girt aspect of the horizontal load if that's a real thing.

 

[JAE]

Right, but that nominal load would be directed along the axis of the member tying in and that direction only, right?

Not if that attached "thing" is perpendicular to the beam.

The OP didn't show anything of that nature of course, but just stating that "no horizontal load is required" might be inappropriately assumed in cases where it does apply.

Realizing that a LOT of original posts don't provide all the details.

Just making sure the OP - or others - don't just take a blanket statement like "no horizontal force is ever needed" and run with it not realizing that there could be "things" that could impart horizontal load via thermal effect, foundation settlements, member shrinkage, etc. that weren't included in the first post.

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[KootK]

The OP didn't show anything of that nature of course, but just stating that "no horizontal load is required" might be inappropriately assumed in cases where it does apply.

Ahh...I see. I guess this is just a fundamental difference in how we two approach our contributions here. I just roll out with whatever the OP's elected to show me and make whatever assumptions I feel are appropriate to facilitate forward motion. If OP, or anybody else, screws something up because I was working with incomplete information, that's on them as far as I'm concerned. I'll not let the perfect be the enemy of the good.

 

[Budding_SE]

When i meant "no horizontal load" is required, by that i meant only nominal thermal will be considered. The fact that i am worried about is if the forest of stirrups would be enough. I dont have the standard corbel here as shown in the section. And this occurs in the interior of the building.

 

[hokie66]

Aside from working out the structural issues, I think your architect needs his head read. This will not read as structurally honest or logical to the casual observer.

 

[EZBuilding]

There is a decent moment that needs to be resolved by the column as well... 550 k*ft