The city came through a neighborhood that I have a rental on and elevated the road about 10 inches and installed new city sidewalks also 10 inches higher and poured a cheap asphalt ramp to the older cracked but functional driveway. In my mind I want to rip out the asphalt ramp, place some forms, and back fill the old driveway with a bit of pea gravel and have a new driveway installed over the old one. Do I really need to rip out the driveway before I proceed? Or will a my idea work? Is there some kind of miracle material that will allow for concrete to adhere to concrete so that it won't shift or get water/ice build up between the driveways in the winter? What do you know?

If you search "bonding new concrete to old concrete" you will find many reliable products. Most of these products have been in use for a long time.
Pea gravel between new and old is not a good idea..

If you tie the new concrete to existing (thin edge of triangle) you will likely have to remove some of the existing concrete to reach a minimum depth to avoid breaking it up with vehicle load. In other words, the concrete should be no less than about 5 to 6 inches deep at its thinnest point.
Will it drain OK?

Concrete is expensive to disposal, and doing the driveway twice would be the outcome of capping the driveway. I recommend replacing areas cracked and coating the driveway with coating. The base a-gravel 12" minimum for concrete will determine the overall life of the concrete. 5" minimum for driveway thickness for sure!

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