Shear friction/Shear reinforcing

[JStructsteel]

I have a ledge for a precast stair bearing. The shear capacity is not enough for concrete alone, so some reinforcing. If I look at shear friction method, would the reinforcing need to be developed on both sides of the crack? If I use a hairpin, is that not just Vs instead of shear friction. What do you guys think?
Thanks

 

[msquared48]

Is this new construction or a remodel?

Mike McCann
MMC Engineering

 

[JStructsteel]

New construction

 

[wildehond]

Would it not be an idea to opproach the reinforcing solution to this problem in the same way corbels are designed?

 

[WillisV]

For shear friction, yes it must be developed on both sides of the crack. Look at it as a beam ledge (similiar to corbel) - see the PCA notes for a good example.

 

[JStructsteel]

I ended up putting some #3 hair pins in the ledge. Its only 4" tall and also only 4" out from the face. Load isnt that high, but want to make sure that I am detailing the rebar right. Thanks guys

 

[civilperson]

The hairpins must be looped around a transverse bar to have development near the bend of the hairpin assuming both tails are on the same side of the potential crack.