Around the perimeter I used a roll foam product. It is made of the same type of foam as what most people use for the termite shield, It comes on a roll about 5 inches wide, 1/2" thick, and the top 1/2 inch is scoured. I used construction adhesive to attach to the wall, the idea is to place the top at the floor level line. You pour your concrete to the top, after its cured you remove the top 1/2" scoured section. This leaves an area that you can caulk or fill with sealer.
I did the same thing at my door openings for a thermal break. I used a pour in sealer "Sikaflex" It dries light grey, and stays very flexible allowing the slab to move.
greg