Concrete Stair Reinf Detailing
Concrete Stair Reinf Detailing
(OP)
Anyone care to opine on how a concrete stair as shown in attached sketch should be detailed in relation to slab into stair bars. Assume slabs are poured first so bars (or dwls) are left for the stair. I'm not concerned with the reinforcing in the guts of the stair, just how the slab top & bottom bars should relate to the stair top/bottom, i.e. at upper landing should slab bottom bars extend and bend down into top of stair slab and slab top bars into bottom of stair slab, or vice versa, or add a 3rd layer of dowels to complete the crossing etc Thanks.






RE: Concrete Stair Reinf Detailing
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: Concrete Stair Reinf Detailing
Stair sidetrack (I'm on a stair kick), do you guys do scissor stairs in ca and if so how are you supporting your dividing wall?
RE: Concrete Stair Reinf Detailing
Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries
www.americanconcrete.com
RE: Concrete Stair Reinf Detailing
Is this a trick question? Support the divider from whatever horizontal thing is at the bottom of the shaft??
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: Concrete Stair Reinf Detailing
Bookowski - are you talking about laterally bracing a stair end wall that is discontinuous from the diaphragm? Had a problem like that where one of the shearwalls I needed for the stair tower was the end wall for the stairs. I wound up designing the stairs to take torsional loading. Lots of fun designing - hate to be the builder - don't do this.
RE: Concrete Stair Reinf Detailing
No, I was talking about a beam (or lack of) between two adjacent stairs. We have 'scissor' stairs here, basically like two corkscrews around each other. They are fire separated, typically by an 8" cmu wall. So it's two stair openings side by side with a wall between. It is common practice here to make this middle beam the same thickness as the slab, so typically it's an 8" x 8" 'beam' that supports that CMU. While I was on my stair kick I was just wondering if this happens elsewhere. It's a really crap detail that makes your stomach churn but since that's what everyone has been doing it's a real arm twist to say it's not ok.
RE: Concrete Stair Reinf Detailing
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: Concrete Stair Reinf Detailing
You would have to use increased radius bends for the bottom steel and I doubt that you have sufficient development for the top steel.
RE: Concrete Stair Reinf Detailing
RE: Concrete Stair Reinf Detailing
I wonder if there might be an opportunity to come up with an appealing precast alternative. prestress it with some little wires and drop it in there somehow. Maybe TME could help out with that if we cut him in on the patent.
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: Concrete Stair Reinf Detailing