Omitting Base Plate Grout 1

[Berniedog]

I have designed a large retail/warehouse store. Some of the columns support 250k loads. The same contractor is pouring the footings and going to erect the steel. He wants to omit the grout. He states that he is going to pour the footings so smooth that the column baseplate will bear directly on the concrete. THese are 10'-0"x10'-0" footings. I do not beleive he can pour the footing to within 1/16" of the proper level. Also , this Contractor is friends with the Owner, so I am hte outsider.

Can anyone help to support the case of keeping the grout? I have read thru Steel Design Guide, 2nd edition.

 

[a2mfk]

My vote: don't allow it! Sounds like bad news... Plus, like others have said, you are driving the structural ship, never let a contractor take the ropes on these types of details. And I am surprised this is not spelled out in AISC?

You will be involved if there are any problems, and the costs of grouting under the base plates would seem VERY minor compared to the cost of the whole building. Why is the GC taking such a hard stance on what seems to be such a small detail? I am also surprised at his cockiness to his concrete work and steel accuracy, the leveler nuts let you make adjustments to the elevations.

Light poles to not have 250k axial load. Also, the bolts and nuts are designed for this axial load.

 

[pwht1]

You might as well get the client and contractor to sign a waiver/legal document (don't know what it is called) that they've not constructed the building in accordance with your advice or the applicable standard.

 

[Lion06]

So I'm a little curious here. You are still the EOR, it's your design. I know we work for the owner (or contractor, or architect - whomever the client may be), but if you're the design professional that is responsible for the completed project then you should be comfortable with every aspect of it.

Where can we as engineers draw the line and say we're not comfortable with that?

 

[Lion06]

Doesn't that also violate a standard of care? I dint know of anyone who doesn't grout base plates.

 

[Lion06]

One more thing to think about and maybe this would change the owner's mind. Let's say for a moment that this contractor has the greatest concrete finisher ever and he gets this tip of footing dead on in terms of flatness and levelness. How will he handle the steel tolerance? The column isn't going to come out with the base plate perfectly orhthognal to the axis of the column.

 

[cvg]

design professional is responsible for the completed design, not completed project. If you don't believe that, than imagine that the owner had not given you a contract for construction phase engineering. Instead, he decided to hire another cheaper engineer to do that. That engineer would then be in your position to review the contractors RFI's, not you. Would you still be responsible for the missing grout? So unless you agree that it is acceptable, then you are not liable. You should make sure you are on record of not approving anything and not recommending any alternative.

 

[dik]

For lightly loaded columns, the lack of grout would be acceptable. For columns loaded as you note, they should be grouted.

If not, you may be relying on the plastic action of concrete, crushing until sufficient bearing is achieved... I don't normally design on that basis...

Dik

 

[BAretired]

The procedure proposed by the contractor may work satisfactorily if his work is as accurate as he claims it is. Otherwise, he may be called upon to provide remedial measures. Berniedog should not accept work which is doubtful.

BA