Crack control for Swimming pools 2

[Iasonasx]

I wonder if there is a code I need to refer to for an already existing swimming pool. If I were to design one myself, I would use the ACI 350, but I cannot claim that an existing pool is inadequately designed because it does not apply the ACI 350 code. Any suggestions on what would be applicable and the minimum requirement for crack control for swimming pools with one layer of rebar (both directions of course)?

 

[JAE]

Dear Pool Owner.
Typical concrete construction under ACI 318 requires X rebar in the pool.
This is for strength as well as minimums for general concrete construction and crack control.

However...

For concrete structures like tanks that hold water (pools), current engineering knowledge and practice under ACI 350 recommends Y rebar.
This is for strength as well as minimums for specific crack control in structures like pools.

Your pool has Z rebar.
Comparing Z to X and Y we see that your pool, as originally designed, is... (you fill in the rest).

 

[Iasonasx]

@JAE, what is X rebar and Y rebar and Z rebar? Here in my neighborhoods we have #3, #4, #5, #6 all the way to $14 and #18 and we arrange them @ 3" O.C. to 12" O.C. mostly. ACI 350 is for environmantal structures. I know it has good formulae to follow, but is a residential swimming pool considered an environmental structure?

 

[jayrod12]

He's using it as place holders for the actual reinforcing values that you either know, or determine.

I.E. X rebar is the amount required under ACI 318, Y rebar is whatever is recommended by ACI 350, and Z rebar is whatever is actually installed. He doesn't know those values so didn't want to guess.

 

[JoelTXCive]

There is a swimming pool and spa building code.....

It looks like they go back to the late 1990's (edit....the codes go back much further than that)

https://shop.iccsafe.org/catalogsearch/result/?cat=1010&q=swimming

I've never looked through the swimming pool code, but there might be minimum reinforcement ratios or other industry standards in there.

 

[JoshPlumSE]

I don't design swimming pools, but one of my good friends spent a number of years doing that almost exclusively. My thoughts:

a) The worst case scenario for almost all pools is when they're empty and the soil is pushing on them.

b) They are designed essentially as cantilever retaining walls.

c) The biggest points where they would deviate from a standard design was when there was a slope (in either direction) close to the pool.

 

[Tomfh]

One thing to be very mindful of is the amount of restraint. Our concrete pool has minimal restraint, it’s largely out of the ground. It is 150 thick with S12-300 longitudinally in the walls, which is quite light. 0.25% steel. Yet very few cracks. None that leak.

If your pool is restrained against shrinkage you need a lot more.