concrete foundation wall expansion joints

[connect2]

So question is thoughts on the requirements, or not, for expansion joints in this wall;

Wall is 1260 feet long. Wall is 16" wide x 6' - 0" high. top of wall is 16" below grade. Delta T is -35 (F) winter to 95 (F) summer. Wall is reinforced EW EF with 20M bars at 6" o.c.
I'm told by 'someone in the know' that the wall doesn't need any expansion joints. I find this curious? There will of course be construction joints but not the same thing.

Thoughts?

 

[manstrom]

Off the cuff, I usually ask for control joints at 25'. Expansion joints at about 100' for a retaining wall.

I'm sure that there is a more specific design method. It is a pretty thick wall, but that won't affect temperature change effects. The bar will restrain it a little, but don't try to fight nature.


When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[jayrod12]

Control joints at 25'? That's pretty tight for a below grade wall. That would mean none of the basement walls poured here would pass your specs. I literally mean none, I have yet to see a control joint in any below grade wall.

Granted I haven't seen one even remotely close to the length described here.

The only issue I could see with not providing an expansion/control joint in a wall this length would be buckling of the wall on the hottest days possible. The wall will be constrained by soil at each end and as such should not be able to actually expand along it's length.

There is also the possibility of cracking on the coldest days from shrinkage but if you rebar mat both faces I can't see this being a large problem.

Also, the temperature swings below ground are no where near what they are in the air. your 130 degree swing in the air might only be 80 degrees or less below grade.

 

[connect2]

Jayrod12

We do get frost penetration to a depth of 6' or more as the area will be cleared of snow and compacted granular will surround the wall. But yes agreed that the wall won't be subjected to the swings noted in my post. There will be a temp gradient from the top of the wall to the bottom. Top of wall likely experience -30(f) to 80(f). Bottom of wall likely 32(f) to 60(f).

It is not a basement. It's an anchor wall for the tie rods of a sheet pile wall.

 

[cvg]

suggest reading ACI 224.3R-95 Joints in Concrete Construction

 

[jayrod12]

If it is just an anchor wall for tie rods and will not be visible does it matter if there are control/expansion joints? Like I said if you provide rebar mats on both faces to keep the crack size to a minimum I don't really see the need.

But again, I've never done something of this length so hopefully one of the more experienced guy's can chime in.

 

[hawkaz]

Is this truly a straight run of 1260 l.f. or are there any jogs in the wall?
I put control joints at 50' o.c. and expansion joints at 100' o.c.

Being a foundation wall, minor cracking probably isn't a big deal- but I personally don't like taking the call "My wall has vertical cracks every ___ feet on center- Why did this occur? Can you meet me at the site to review these?" Putting the joints in saves this call.

 

[connect2]

hawkaz - yes if no expansion joints, then other than the construction joints, the wall will be 1260 feet long.