pressure treated 6x 6
It may or may not be approved. Sticking wood in concrete is generally a bad idea, unless there is an over-riding reason. When the wood eventually rots out, you will more than likely have to remove the post and foundation unless you think you want to try the same thing again.
The best route is to use a galvanized steel attachment bolted to embedded into the concrete. Then the post is attached to the bracket that keeps it away from the moisture (especially at the ground surface), which experiences variation between wetting and drying that really tears wood apart.
Last edited by concretemasonry; 10-19-2011 at 12:36 PM.