Anchor Rod Setting Plate
Anchor Rod Setting Plate
(OP)
We have just recently had the anchor bolt fabricator providing 1/4" setting plates that are welded to the anchor rods to assist the installer in setting the rods. Our current project, the installer placed the setting plate flush against the concrete footing leaving no void between the two. This to me seems to be an issue as th top of the footing is rarely flush and smooth. This could create a void between the setting plate and footing and inturn could create a void below the structural column base plate. My question is whether anyone has a good reference on how these rod and plate combinations are to be installed? I feel the setting plate should be left up from the footing to allow the grout to be installed under the setting plate but could be wrong. Any feedback would be appreciated.






RE: Anchor Rod Setting Plate
Dik
RE: Anchor Rod Setting Plate
It's not just a bearing issue - usually the top surface of the footing is reasonably smooth. But if there's no grout, I don't see you have any adjustment for the steel - the concrete better be PERFECTLY level in order for the column to turn out plumb... And if it's not, how do you fix it except by adjusting the angle that the column attaches to the base plate? Are they going to measure every one of those with a precision necessary to adjust prior to column fabrication? More than likely no, and even if they were, they'd drive the steel fabricator insane. It may depend greatly on how tall your columns are - they're only 10' tall, they might not have any trouble meeting tolerances (even though it's a crappy detail). But if you've got a 3-story, 55' tall column - good luck getting it plumb.
As far as references, I just looked up page 14-7 of my AISC 13th edition. If you've got a different edition, just look up "grouting and leveling" in the index.
Final thing is with reference to welding the setting plate to the anchor rods. In general, I HATE welding to any kind of bolt. If you're a grade 36, you might be able to get away with it, but in general I discourage any kind of "bolt / threaded rod" welding because it promotes bad habits. High strength bolts shouldn't even be tack welded. The other thing with this is "welding" them also ruins the leveling adjust-ability just like placing it tight against the concrete. I don't know why you'd want to anyway - a nut on each side of the setting plate is more than enough to keep it from moving and is less money/time/effort than a weld.
RE: Anchor Rod Setting Plate
RE: Anchor Rod Setting Plate
The only purpose I've seen with setting plates is to insure that there is grout continuously under the base plate, and not to secure the anchor rods.
Dik