Cracked and settle concrete slab around IG pool

[garywallace]

Hi all, as you can see that I have started to remove cracked and settled concrete around the pool. I want to install pavers. This pool is old but not sure how old it is - must be 30 or more years because owner kid mention that she used to swim in it and she is around 50.
Thikness vary of current slab, 4 to 5" around pool parameter and 2" at the farest end.
I can see that original base has settled around 2" to 4" or more!
1. how much should I compact it.
2. I am thinking to settle this concrete in the dirt, use as base - is this ok? I will make pieces smaller than what is shown. 3. I have a small compactor to compact, see pic.

So question is that is my plan safe?
Thanks

 

[duraleigh]

I wouldn't do it. By the time you get the concrete busted up as small as is needed, you could remove it and put in a much better fill. That concrete will leave to many voids and your subsurface will settle again.

I think I would bite the bullet and remove the concrete, then bring your subsurface up to the correct height with rock and gravel/sand depending on how much elevation you have to add.

The compacter is probably of little use. The subsurface under the concrete has likely settled all it is going to so now all you have to do is bring it back up to grade and install your pavers (if you remove the concrete.)

 

[anonapersona]

What is that round thing, almost looks like an irrigation pop-up site? I'm wondering if that has anything to do with the cracking.

 

[JohnT]

I'd be worried that when you push the concrete down it will push in on the pool wall.

 

[garywallace]

Thanks for all for your advise.
I think it would be safe to get rid of concrete and fill it up with aggregate and sand.
Round thing is skimmer's top, original owner must have broken the original lid. Actually pool slab is cracked all around. I just took picture of one side.
Thanks again for your help.

 

[kerryN]

i thought mine was a nightmare good luck

 

[premierpoolproducts]

Always remove the concrete pieces bigger than a 2". Fill with a crushed aggregate/limestone. Then you will want to vibrate it with your plate compactor. This will help your new slab from settling. The aggregate that you do fill with will settle about a 1/2"-1" with a 4" fill. So yes, do vibrate it! Just be carefull around your skimmer and pool walls as you can move them with the compaction.

 

[duraleigh]

#57 aggregate is commonly available and requires no compacting in that it can't really be compacted.

If I were doing pavers, I would clear out all but the smallest of the old concrete pieces (nothing bigger than about an inch and it will mix well with the #57) and then bring the #57/concrete mix up to about 1/2" below grade (plus allow for the paver thickness) for the substrate.

Next, I would bring in sand to fill in the voids between the rocks and to bring the substrate up to final grade, The sand WILL settle into the voids between the rocks. Time, rain, and wetting it down will help it compact. The plate compactor will probably not do too much good but it might help.....I just don't know.

Once the sand has stopped settling into the #57, you can bring it back up to final grade and set your pavers.

A second option would be to simply pour a concrete substrate but that probably is not a DIY option.

 

[premierpoolproducts]

You would be surprised by what an actual piece of compaction equipment could do for you to prevent further settling. After all, that is what they are designed for. Water compaction is another method, yes. But to get the actual compaction level of a mechanical compactor, it would take a very long time. Most water compaction yields only about a 90% proctor. Where as mechanical you can yield up to 120% depending upon the material. If you are going pavers, I would highly recommend a paver sand, and not play sand, as paver sand is irregular in shape and helps "lock" together to form a stronger substrate for the pavers. But if you are only going to pour a concrete deck, then there is no need to add the extra sand on top of the crushed rock you used to backfill, the concrete will fill any "void" that you get from the rocks. But you really shouldn't have any voids to fill after a proper compaction. Either way, let me know if you need anymore advice on pavers, as I am ICPI certified and have installed hundreds of paver jobs, commercial and residential. Not to mention the thousands of different pool decks we have completed over the years!

 

[garywallace]

duraleigh & premierpoolproducts, thanks a lot for the valuable information, of course, i will post more once I get close, this is a weekend kind of job and will take a longer time. Again, thanks a bunch.