In Oklahoma, folks love their water in the hot summer months.  Many customers in Harrah, OK have pools built on clay backfill so the pool decks have a tendency to settle after the first few years.  In many cases, this is caused by rainwater and splashing getting between the joints cut in by the contractor.  This joint allows water to slowly seep into the underlying fill dirt and settle.  The best way to prevent this is to have the joints sealed with a proper concrete joint sealer.  For year customers have assumed urethane caulking is the best suited for concrete, However, silicone based caulking with UV inhibitors are a far superior option with today's technology.  By installing UV protected Silicone caulking and finishing with a color match sand you can expect a 5 plus year solution.  If you have voids, it is best to protect the concrete from future settlement by pre-installing concrete slurry or foam injection.  Below is an image from a recent repair made in Newcastle, OK This is the best solution by far to making sure you concrete will last longer than the pool itself.  For more information on pool deck repair maintenance and repair; feel free to contact the professionals at Vesta Foundation Repair.