Expansion joints cut in wrong location

[Diesel Dan]

As the title states I have a possible issue with a location of an expansion joint cut into my new floor.

Had 36"x36" pads 6-8" deep for where the hoist is to be anchored.
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Brought lift columns in and set in place and here is what I found:
[URL=http://s811.photobucket.com/user/dsl4me/media/1022131318-00.jpg.html] [/URL]

The saw line is basically right down the middle of the pads following the orange string line in the first picture. Did not get a chance to call Hilti today and was wondering what others think.

Thanks, Dan

 

[RivennHewn]

What's your fear?

 

[Dan in Pasadena]

Those aren't "expansion" joints, they're crack control joints. The fault created by the saw kerf is where the slab will crack if it's gonna crack (and it will). A real expansion joint will have a flexible material in it to expand and contract with the growth & shrinkage of the slab due to temperature.

I'm pretty sure you have a non-issue there.

 

[Diesel Dan]

Yeah, kinda figured I was using "expansion joint" in the wrong way.
Isn't there a minimum distance to use a 3/4" anchor bolt from cracked concrete? As stated it will crack at the cut.

What's your fear?

A 9,000lb truck 6' in the air?

 

[RivennHewn]

Yeah, kinda figured I was using "expansion joint" in the wrong way.
Isn't there a minimum distance to use a 3/4" anchor bolt from cracked concrete? As stated it will crack at the cut.


A 9,000lb truck 6' in the air?

Where's it going to go?

 

[RivennHewn]

I've had engineers spec 3.5 times the diameter of the bolt from center of bolt to edge of crack or edge of concrete.

If you use longer bolts that go into the thickened footing, you should be fine.

You could drill and epoxy all thread, that way there would be no sideways force on the concrete from the wedge type anchor.

You could also fill the gap with grout between the anchors.

Cheers

 

[Diesel Dan]

Called Hilti today and received an answer.
With the type of bolt I have I need 8.25" or greater hole spacing(C/L) and I have 9" so it is OK.

Glad I found out because it is one of those things you always look and wonder.