A common way to deal with cracked or chipped concrete is by using polymers to coat the old concrete.  Polymer and resin work together to make epoxy floors, which are common in many garages.  These compounds are place in the new concrete, and applied on the old concrete once it has been cleaned for leftover debris.  the polymers in the new concrete give it a stretchy quality, and it can sag a bit more than regular concrete.  This leads to a longer life of the patch, which ultimately saves money.  It sure beats having to repave a driveway every few years, and it is easy to do yourself.