Typically the gut reaction seems to be, No way! Rip out the asphalt and start from scratch! But I have seen some reports from people who seem to know the process well that having an asphalt base actually is not a bad idea at all.
To explain better what I am doing: my 40 year old home has a garage where the asphalt floor is badly misshapen and bowed and especially sunken around the concrete foundations. It is in bad need of a resurfacing. I am just trying to figure out how I can remedy the situation without having to spend more than necessary.
So what are the issues with just pouring over top of the asphalt? It might be safe to assume that any settling has had many years to sort itself out. But I know very little about either asphalt or concrete.
Best Answer
Concrete isn't for resurfacing. It's a structure unto itself. So you need to likely pour at least a 4-5" slab for it to work as new garage flooring.
So that means your current flooring would have had to sink 4-5" already. The catch with that is that for it to sink (at all, really) it means it had a poor base to begin with (or no base).
As such, I'd say this is a bad idea.
I think the arguments for pouring on asphalt would be that if the asphalt has remained in good condition, it's likely in no small part due to the good base it had.