Waste concrete is quite possibly my most favorite hardscape. Why? It is FREE, usually easy to find, durable, and pretty good looking. Another bonus, if you are not a professional brick layer or paver installer, this material is pretty forgiving…no one expects it to look perfect. But that is all part of its beauty.
While laying anything over a sand base is always easier, with a little love (and potentially quite a bit more time) these can be placed directly onto dirt. You can fill between the cracks with more dirt, and/or sand, gravel, or dg (decomposed granite). If you choose mainly dirt you can also plant things that grow in the cracks (we are talking walk on plants such as moss or creeping thyme). But realize, things WILL grow between the cracks whether you plant them there or not. You can prevent this by putting down weed block before placing the concrete, spray herbicide (yuck!), using a weed torch, or simply pull them as they grow…or embrace it and just keep it trimmed so it doesn’t look to unruly.