Does 5200 adhere to concrete?

I suppose one could screw the wood to stainless steel and then epoxy that to the concrete to get expansion rates that are close. I haven't tried it.

 

Given that the epoxy will restrain the wood based on the stiffness of the concrete, you would have to have no strength in the wood (rotted) for the wood to actually tear.
In this case the wood is reinforced by the concrete. Since the strength of the wood is not all that high (especially softwood) the wood will not tear apart.

Try it - you will like it.

Again, practical beats theoretical every time, especially if you are taking a simplistic view of the situation.

You know, you might look at the strength of wet wood, it goes down in a similar relationship as the swelling goes up. Again its doubtful that the entire block of wood will gain the same amount of water (I may be wrong in Florida or the tropics).

Bondo works just fine also, but a sharp blow in shear will cleanly break it loose from the concrete. Otherwise it will last a long time, at much lower strength than epoxy.

 

I have seen wood break at a glue bond. The glue tears the fibers off the rest. This is not theoretical. The data from the calculator isn't either, it is based on experimental research.

 

I give up.

Anything will break at a bond joint with enough force.

Absolutely true.