Grouting between steel beam and steel bearing plate

[Skip517]

I have a job where the concrete contractor installed the steel bearing plates out of level. Please see the attached picture. The concrete pier below is 12"x24" the beam is sitting on the pier in the length direction (24") There is a steel bearing plate cast into the concrete. The beam is supposed to be welded to the bearing plate. (The anchors shown are only weld on threaded anchors for erection only.)I was thinking of using a series of plates to complete the shimming process, but in some cases the plate is out of level in both directions, so the plate thicknesses would vary on each side of the flange. After the shimming process, does anyone have any ideas on a grout to use to fill the gaps. Standard non-shrink grout (under a column base plate type) would be difficult to get into the voids. I am open to any other repair ideas also.
Thanks.

 

[JAE]

I'm not sure what the purpose of the embedded steel plate is.

But in any case, my first thought is to somehow inject some type of epoxy grout into the space. I would probably contact some epoxy grout suppliers and speak to their technical reps there about sandwiching their product between two steel surfaces.

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[IRstuff]

I think you need to determine the intent of the welding. Was it intended to eliminate bolts that might have otherwise served the same purpose? Grout, or even epoxy, isn't necessarily going to provide the same mechanical characteristics as a weld.

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[MotorCity]

If the beam is supposed to be welded to the plate, then grouting or epoxy will not provide an equivalent connection. I would use tapered shims or flat stacked shims welded in place.

 

[Skip517]

My main concern was bearing for the steel beam over the pier. When I calculated if stiffeners were required I used the full steel bearing plate length 22" in this case and stiffeners were not required. I went back and looked at my calculation, and if I changed the bearing length to 19", it says stiffeners are required. I can have stiffeners added in the field, but if I used stepped shims, does this still count as adequate bearing? Should I have it grouted after the shims are installed?

 

[EngineeringEric]

the thing could be grouted/epoxy then plates welded to the outside of the flanges and embedded plate.

 

[BAretired]

It sounds strange to me that you need stiffeners with 19" bearing if you are talking about web crippling. You must have a very large reaction. On the other hand, stiffeners might be a good idea for beam stability.

It appears to me that the top of pier is close to level but the beam is not. I can't say I like the idea of epoxy grout because the "E" value for epoxy is probably much less than that of concrete.

I'm wondering about a high strength flowable liquid grout which could flow into the small gap between beam and plate. There is not much room for placing dry pack grout.

BA

 

[EdStainless]

We mounted some equipment that was welded to embedded plates, And there was a threaded hole beam near the center of the mounting plates. After welding we injected an epoxy to fill any gaps under the beam.
The issue you have is that you need the correct weld gap, that will require shims. You can't weld in the air.

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[IRstuff]

The intent of the bearing plate, apparently, is to spread the load. So the question, then, is whether the shims or grout will do that.

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[Skip517]

Thanks for all the input. I think I am going to go with stepped steel shims welded in place. Fillet welded where there is adequate material, and gap weld the thinner areas with the shim plate acting as a backer bar. I am also going to add stiffeners where I feel bearing is a concern.

Thanks Again.

 

[MotorCity]

So if bearing is the concern, then there is no reason the beam has to be mechanically attached to the embed plate (other than the erection bolts that will maintain the beam's location). If that's the case, just grout the gap and you're done. If there is any axial and/or lateral load on the beam, then the beam should be attached to the embed plate using tapered shims or EngineeringEric's suggestion

 

[Lomarandil]

Agreed, it sounds to me like grouting should be able to accomplish most of what you need.

I've had good success working with 5-star grout in a similar, high demand application in the past. We both were able to get some good support from the company staff determining how it would perform in an atypical application, and then the product worked well.

(for the curious, the grout was used to ensure good bearing across an interface despite some weld distortion in the heavy steel elements supporting this operation)

https://www.youtube.com/watch?v=3ov_7TVC8ic

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