I have a concret fish pond. like to use plastic sheet as liner. I like to bond them togeter.
Buy some clear cement adhesive. Use in standard caulk gun. This stuff works very well but clean cement first with a good cement cleaner and for really bad stains/spots use muratic acid and flush off completely, then dry good from sun. I am not real positive this adhesive will come in clear and if not the adhesive may show through. You may have to buy it by the can and brush it on.
Reasoning escapes me for the gravity will hold the water down which will hold the plastic down. If you are talking about the edges, go to the builders supply and get a tube of PL400(or 500, or 600, or 700) Whatever works on plastic. Read label.
Generally, you would place a plastic or rubber liner in the hole and place rocks/gravel on top of the liner in the hole and larger rocks around the perimeter, meaning you don't need to bond or glue the liner and concrete together. Read the article I linked to for more information.
