CRSI skip joist tables min stirrups 1

[haynewp]

In CRSI (I have the 2008 version), there is no mention of providing minimum stirrups where Vu is greater than phi*Vc/2 in the Chapter 8 joist tables. The example on page 8-9 also does not mention providing stirrups and only compares the shear to phi*Vc. Does anyone know where this is permitted in ACI 318 for wide module joists? I am getting a shear failure in SpSlab that appears to work by the CRSI tables because SpSlab is using 1/2*phi*Vc as the permitted limit without having any stirrups. The joists in the tables I am looking at do not require the joist tapered ends.

 

[KootK]

See this article from which the blurb below was taken.

I believe that this was a change to ACI somewhere along the way. Shear design is allowed to be a bit more liberal when proportions are such that behavior is thought to be that of a ribbed slab rather than an isolated beam. Nowadays, wide module of joists now fall into the category of beams. T-beams to be exact.

 

[KootK]

This is what 318-19 has to say about this issue. There, the transition happens at a joist spacing of 30in.