I spent yesterday busting up a 20' x 40' concrete driveway in my backyard. It's been the plan since I bought the place 5 years ago, but I finally got the nerve to do it. The previous owner told me he'd wanted to do it, but it seemed like too big a job. No fooling.
I used a 60lb. Makita 15 amp electric jackhammer, and a pair of prybars. The first discovery was that the perimeter is about a foot thick. Most of the concrete is a high ratio of large aggregate, which was difficult to work. Other areas had almost no aggregate at all, so the jackhammer just punched a clean hole in it. Luckily, no rebar. The next discovery was a second slab underneath, about 10' x 20'. It looks like they didn't bother to prep the area in any way, just dug out the perimeter, put up some boards, and just poured and poured until it was about 4 inches thick over the old slab. As a result, the thickness varies from 2 inches, to 12 inches. Nice work, guys.
Now, I get to haul all this away.
I used a 60lb. Makita 15 amp electric jackhammer, and a pair of prybars. The first discovery was that the perimeter is about a foot thick. Most of the concrete is a high ratio of large aggregate, which was difficult to work. Other areas had almost no aggregate at all, so the jackhammer just punched a clean hole in it. Luckily, no rebar. The next discovery was a second slab underneath, about 10' x 20'. It looks like they didn't bother to prep the area in any way, just dug out the perimeter, put up some boards, and just poured and poured until it was about 4 inches thick over the old slab. As a result, the thickness varies from 2 inches, to 12 inches. Nice work, guys.
Now, I get to haul all this away.