Marin,
Thanks for the info. Your directions/advice is very clear. I decided to cut the deck/coping 10" in from the edge. I'm using my 7-1/4" circular saw with a 7" diamond blade. It is going pretty well but I can only get about 2"-2-1/2" depth to the cut. I have already demo'd the deck from the cracked joint out. So after I make the cut I give the edge a good smack with a sledge and it breaks off. My problem is it still leaves about 1-1/2" deep of rough deck/coping concrete. (the concrete is 3-1/2" deep and I'm only cutting 2-1/2" deep.) I'd like to avoid renting a big saw because the small saw is very easy to control. It also cuts the curves quite well. I'm thinking of putting the 7" diamond blade on a 7" grinder wih no guard, hoping to get another inch of depth to the cut. (kind of dangerous...) So then I will compact crusher-run gravel flush to the top of the pool bond beam then pour the new deck over the compacted dirt/gravel and it will sit on (overlap) the top edge of the bond beam by about 2". Now I just need to decide if I will use an expansion joint or pour right up to the existing coping remnant then cut a control joint right at the same deck to coping joint. Any thoughts or advice on this plan?