ICF maximum control joint spacing?

[southard2]

Does anyone have any code reference, rule of thumb, or calculation method to determine what the maximum wall control joint spacing can be for a long ICF wall. With tilt-up I've gone a bit over 30 feet before with no problem. Of course these walls are exposed. I've even tied up to three panels together with plate to plate connectors. So this could be up to about 60 feet.

The ACI code requires a maximum horizontal spacing of 18" o.c. vertically and also a higher minimmum reinf ratio than even the vertical reinf. I'm at the house so forgive me on the approximations.

For residential construction polysteel sent me some stuff showing through some testing that you could go beyond the 18"o.c. rule. That said this is a commercial project and I'm basically following all the design rules for tilt-wall construction including the maximum spacing and reinforcment ratio requirements. Except the code appears silent on control joints. With all that reinforcement any cracking should be held together pretty tight.

Thanks in advance everyone.

John Southard, M.S., P.E.

http://www.pdhlibrary.com

 

[TXStructural]

Assuming you are using flat wall ICF's, the design should be as for cast-in-place walls. The EPS will assure an excellent curing environment, particularly for high SCM replacement mixes. You can go a virtually unlimited length in most applications with good building layout and proper mix design.

Precisely because of these kinds of questions, ACI Committee 560 in the process of generating a new document to help designers know the state of the ICF industry and identify design resources.

Where the application must remain watertight (basement walls), formed vertical joints with waterstops can be used. It is likely that cold joints, such as along the footing at the base of the wall, will be subject to moisture movement, so plan to provide adequate drainage, have a moisture barrier outside of the EPS, or use other measures.

 

[a2mfk]

Expansion joint or control joint?

I don't know what the plan view looks like, but you may also consider expansion joints at typical locations as you would for CMU or tilt, such as wall returns, Ts, etc...

As far as expansion joints for crack control, you are providing shrinkage reinf. per ACI for walls which I think is a huge help. But I think the difference with tilt panels is that a large amount of the shrinkage has taken place prior to the walls being erected. And a lot of tilt panels may be considerably thinner than your ICF wall?

What kind of length are you talking about?

Another cause of cracking in concrete and CMU walls is the difference in expansion/shrinkage of the footings and the walls, better, their incompatibility. Another reason to at least consider expansion jts.

Maybe this helps a little..

http://www.nrmca.org/aboutconcrete/cips/07p.pdf

HTH,
Andrew Kester, PE
Florida