Suspended Pool

[RAGE69]

Hi All

I am building an above ground pool sitting on concrete piers founded onto rock(due to slope of the land most of the pool including the base is above the ground).

The engineer has specified N12-200 bars each way on each face.

Trying to get quotes and a pool contractor to build it - all of them complaining that they normally use S12 bars and not N12 bars when constructing pools and that N12 bars make the build too difficult.

I would be of the opinion that the engineer is correct but I have had several pool builders say the same thing.

Is this a case of a conservative engineer or more a case of a contractor wanting to take the easy option instead of doing what is correct

 

[r13]

FYI Link. However, there maybe different structural consideration for elevated pool as opposed to the typical ground supported pool. Suggest to check with your designer first.

 

[hokie66]

The N12 (500 MPa) bars are stronger, but much more difficult to bend. The S12 (250 MPa) bars are primarily used these days for free form domestic pools. If the reinforcement is to be shop bent, the N500 will work fine, but the pool builders are correct if the bending is to be done on site. If the engineer has specified N12-200, then you will probably need S12 bars at closer spacings.

 

[JoshPlumSE]

What Hokie said.

The pool contractors really prefer bars that are easier to bend. And, for good reason... think about how many bends they do for these pools on site. Engineers who are not used to working with pools will often specify the types of bars (diameter or strength) they use on other projects. But, that is guaranteed to upset the pool contractors.

That's not to say that it can't be done. But, I'd check with the engineer to see if he/she can appease the contractors request. Maybe tighter spacing will be required. But, that can be a good thing for crack control and such.

 

[Agent666]

Strength usually isn't an issue. Most of the time limiting bar stresses in pools is more appropriate to limit potential cracking and address watertightness. Pool design is almost never a ULS problem. So that might be the reason they state 250MPa bars are preferred.

If you're governed by some strength limit state, I'd hazard a guess you're going to have serviceability issues for a pool.

 

[Tomfh]

S bars are standard for residential pools because of all the curves. N bars are an odd choice and it’s unsurprising that the builders are complaining.

My pool is 40 years old, 13m long. Partially in ground.

150 thick, single mat of reo, central.

Walls: S12-300 verticals, S12-200 longitudinal.
Floor: S12-300 each way.

Pretty light reo compared to what AS3600 recommends, but it’s performing well.

 

[engineering_patrol]

Check deflections and SLS states as well.