Is clearance needed at the 2nd-floor columns

[eatapeach]

Where a column passes through a 2nd floor and 3rd floor concrete slab, should there be any clearance provided between the column and the slab? The drawing does not show anything; it just seems like you would not want the concrete to bond to the steel column. The first-floor slab on grade had blockouts around the column, the 2nd and 3rd floor is metal decking

 

[GeorgeTheCivilEngineer]

No I wouldn't expect blockouts in that situation. The slab on grade has different support and foundation conditions to the steel column, the upper floors are essentially all the same structure.

 

[JAE]

If the column is supporting something separate from the main structure of the 2nd and 3rd floors and the two structures have differing lateral drifts under loads, then the gap should try to accommodate those lateral deflections at each floor...plus some additional width for safety. Otherwise the column might lean and begin bearing on the floors inducing bending in the column...or the other way - the floors drift laterally and bend the column.

 

[phamENG]

The drawing does not show anything;

We didn't design it, so we can't tell you. Submit an RFI to the engineer of record if you're concerned.

 

[eatapeach]

Thanks for your replies. It is only supporting the roof. Therefore, I think we are good. PhamENG, your answer sounds good; however, in the construction world, most engineers do not like RFIs and take their time responding. Typically, two to three weeks is the timeframe, especially for projects of my size, which are usually over $ 100 million, and unfortunately, the construction schedule doesn't allow for that. Often, issues are discovered a couple of days before a concrete placement, and you pick up the phone to call the engineer, but he doesn't respond within 48 hours. The contractor takes a risk and makes a decision.

 

[phamENG]

Sounds like you need to work with better engineers. Or at least with better firms that have their act together.

EDIT: another possibility....is this your SOP? Assume all engineers will take 3 weeks and just do something without checking first? I've met plenty of contractors that do that. And if I get a contractor that calls and says "I didn't know what you meant here, so I just did this completely different thing and need you to okay it"...it lives at the bottom of my to do list for a while. If a contractor calls up and says "hey, we ran into this issue and it may cause delays, we need help"...then I do everything I can to get it taken care of - even if it means driving a couple cities away on a Sunday to do an inspection because we finally go a weather window that worked after waiting a couple weeks. But the cowboys who like to do their own thing and expect me to bend over backward to reverse engineer it and say it's okay when a call could have solved it in 5 minutes...you're going to lie in that bed for a long time. I'm not saying that's you...I have no idea...just suggesting that the engineer might have come to that conclusion for one reason or another. Or they're just horribly unorganized and don't know how to manage a project. Though a firm designing $100M projects should have a clue. Should.