composite steel beam design - lateral restraint of beams - fire protection of steel beams

[JohnnySm]

Dear All.

5 storey steel frame building (residential). Steel beam with steel/concrete deck flooring kingspan or something.

1. is it sufficient to assume that if the decking trays are positioned and cut correctly, so as to ensure a trough of the deck lies on the top flange, can beams running parallel to the span of the decking be assumed laterally restrained with the use of designed shear studs? i know this is the case with beams spanning perpendicularly.

2. The beams are not designed for composite action but have been designed for full lateral restraint only FYI.

3. in terms of fire protection i know a lot of fabricators assume top flanges of steels where shear studs are located should arrive on site unprotected? is this because they assume i have designed for composite action between the slab and bean? i have not... furthermore with trapazoidal decking this leaves approximately 50% of the top and untreated flange exposed after installtion? should i request these voids to be filled in on site? this seems like something i think the site workers would want to avoid? is it not more preferable to just have the steels fully protected during fabrication? or does this conflict the shear stud installation process? is it standard to request voids filled in on site?

Kinest Regards
JS

 

[dik]

Thanks for the re-locate... for others, the initial comments were posted in Foundation...

Dik

 

[AnimusVox]

I don't consider composite steel beams to be laterally braced while the concrete is wet if the steel deck is parallel to the beam. I feel like the decking would, at best, act like an accordion and not provide lateral restraint of the top flange. Most engineers I know agree with this.

You could reach out to the decking manufacturer and ask if they have any test data that proves otherwise, though.

 

[dik]

Animus: The beginning of this thread is in Foundations.

thread256-427690

Dik