Concrete Bond Collar

[jjboods]

I am DIY building a polymer wall pool. The are is very tight and I am trying to firgure out how to get the concrete around the outside perimeter of the pool walls. My question is this...how necessary is the concrete? What purpose will it serve other than securing the walls in place? And if that is the only purpose, why will concrete do a better job than the tons of backfill that will be used? My grandmother had a pool when I was growing up and I remember my mother telling me it was basically built out of 2x4's. Is the concrete collar just a security measure/overkill? I understand it is recommended, but what are the potential problems that I might encounter if I don't use it. I would still use a concrete collar around the top after backfilling.