Re: Quikrete molds and concrete products versus urbanite
I've used both.
As for the form, you can used the "stones" individually to freeform walkways. In my case I had several wheelbarrows of left over concrete from a project. Rather than making blobs that would be tossed into the trash, I used the form on a piece of plywood. The concrete was stiff enough to hold its shape with the form removed, so the process of forming the "stones" went quickly. Once cured, I installed them into a path between my driveway and lawn. Using the form as the pattern because it is designed to interlock with itself, I laid the path. You can increase the spacing a little to create curves or flairs, or leave stones out to have a more natural / irregular look. You can also use the form directly to create the path in place. As long as the cement is stiff enough to hold its shape, you can remove the form and set it in the next place to continue. I've also used this method and once cured moved the stones as earlier described to suit the needs of the path and custom formed a few stones as necessary as fillers.
Reusing concrete waste (patio/walkway demolition ) is a bit trickier. I wouldn't try to use it as a walkway, but I have used it many times with great success in small retaining walls. You have to use care in how you stack it so that you maintain a plumb and level wall. They also need to interlock for strength. I wouldn't build a retaining wall any higher than about 2 to 3 feet tall, and I certainly wouldn't use it as a structural retaining wall, only decorative. Pay attention to the "face" of the rubble so that each block has about the same look as all the others in the wall. Periodically use extra long pieces that stick out behind the wall that will key into the dirt and keep the wall stable and vertical.
If I had pictures of the walkway or retaining wall I'd share them with you.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!