Build over an existing road?

[Toomanytools?]

Ok would like to get my shop going this summer. The planned location is where our current asphalt driveway comes in. The plan is to have a garage door at both ends drive off the street where current driveway is, into shop then out the other end to a new semi-circle driveway down a new driveway in the middle of the property.
Question is do I leave the asphalt put down 4-6" of gravel put up the pole building, pour concrete. Leaving out a few steps but basically what I'm asking is or do you see any problems with concrete over the old asphalt? It is an older driveway has some cracks going all the way across 12'., but not loose falling apart. I've asked a few builders/concrete guys getting answers both ways leave it and take it out.
Thanks for the input
Thanks Jeff

 

[Sureshot]

What is the reason they give to take it out?

Seems like a great base to me.

 

[Toomanytools?]

Possibility of the concrete to crack , the concrete is going to crack that's a given. I think it will crack less over an undisturbed base.

 

[Spink]

I had the same question. My Base is 19x16' and 90% of it has been poured over a new asphalt driveway. I was getting both answers to take it out and to leave it. Time will tell the true answer.

Not your answer but that's what i did.

 

[Will67]

I vote to take it out put an engineered base material in a compact the hell out of it. Asphalt can crack, but usually just move ever so slightly over time to adjust with the movement of what is laid over, giving you a false sence that base material is solid.
I am not saying that you won't be fine, but it is easier to do it right the first time, then tear it out and do it over with the structure there.

 

[Kevin54]

I vote to take it out put an engineered base material in a compact the hell out of it. Asphalt can crack, but usually just move ever so slightly over time to adjust with the movement of what is laid over, giving you a false sence that base material is solid.
I am not saying that you won't be fine, but it is easier to do it right the first time, then tear it out and do it over with the structure there.

Stone will move more than the asphalt will unless you really take the time to tamp the hell out of it. Most guys pouring a floor will backfill with stone, level it out and pour concrete over it. No tamping. I wouldn't have a problem with concrete over asphalt AS LONG AS it was under roof. Out in the open with freezing and thawing, then that is a whole new ballgame.

 

[Toomanytools?]

I'm leaning towards removing but that's 12'w by 65'L and 2 or 3"s thick to haul off somewhere. Guess I'll decide when I see what it's going to cost to remove it.