I don't think PVC pipes alone would be appropriate as a handle. In the past I have used PVC pipes in conjunction with wooden dowels filling the center void. The wood adds a lot of stiffness to the structure by virtue of material properties and geometry.
I find that this sort of configuration gives a very strong structure, especially at the joint since you can have as long a dowel running into the axe head as you can muster and not just a threaded joint that would be a mere inch or two in length. By having judicious use of PVC pipes, unions and other premade joints you can make all kinds of collapsible nonsense. I made a Nami staff that came apart into 3 pieces with little issue using this method.
Additionally on this thread I hypothesized how to make all of the components of the axe using previously used techniques that I have tried out on other props.
Good luck and happy cosplay!