Hollowcore Slab + Cold Formed Steel Walls 1

[srazahz]

Hello,

Please refer to the attached sketch, the hollowcore slab is falling slightly short of the actual bearing length and I am looking to fill in the void properly and provide proper bearing and connection for jack and king studs that are taking larger loads. What would be the best way to do that?

 

[Tomfh]

Ought we have seen any yet? Or haven’t they been tested yet?

 

[KootK]

I doubt that anybody's out there testing chordless diaphragms. Like everything else in our sphere, there are are no issues until we push the envelope far enough to create them.

Historically, your multistory hollow core buildings had block or concrete walls. drifts were minimal, and just plank friction against bond beams was probably enough to engage this bond beams as chords

Now enter CFM walls which may be panelized with no continuous chords. And shearwalls possibly of gypsum sheathing. Is that enough stupid to start seeing problem? Dunno. We'll eventually see plank on wood walls of course. At which point, among other things, we might need to start respecting compression perpendicular to grain.

HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me:

http://www.eng-tips.com/viewthread.cfm?qid=456235

 

[Agent666]

Hollowcore needs some careful detailing/considerations I agree. Luckily if you mentioned untopped units round this part of the world you'd get some WTF why would you ever do that type of looks. Similar response I expect if you'd try put it on a cold formed stud wall like the original detail.

Some of the issues in my own local market are detailed in this document, issues should be more or less universal though.

 

[jayrod12]

We'll eventually see plank on wood walls of course. At which point, among other things, we might need to start respecting compression perpendicular to grain.

Are you serious? Eventually? They're already being done around here.

 

[dold]

Might be drifting a bit here, but what are yalls opinions on collective chord action? Dependent on stiffness of course but basic concept below.

https://digitalcommons.calpoly.edu/...httpsredir=1&article=1070&context=aen_fac

 

[KootK]

I feel that it's probably closer to the truth in systems suited to that kind of behavior.

HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me:

http://www.eng-tips.com/viewthread.cfm?qid=456235

 

[dold]

I've argued that it is more realistic to consider collective action especially when you have continuity ties (plates on top of bar joists and angles on JG's). It's one thing to use continuity ties for OOP wall action until you've developed into deck, but to tie every single joist and JG in the entire space, you've effectively created a secondary (or even primary) diaphragm. Any arguments against that theory? Talking big tiltup flexible diaphs here.

 

[Tomfh]

KootK, I meant has there been any decent earthquakes to test the performance of them.