Are stones, ranging in size from 2" to 6" in dia, good or bad in fill dirt for an area to be poured with concrete? I'm wondering if I should sift though it and get them out or leave them in.
Seems if the stones don't impede you packing the dirt for a base under the concrete, then they shouldn't hurt anything. You want a dense material for a base, and it can't get any denser than stones. But if using a tamper to tamp the fill doesn't work because of the stones, then they are not good to have.
Depends on the depth of the rough fill (2-6" stones) because as mentioned if it doesn't pack down, voids will develop in the fill causing settling in the future. I would think that 12" or less properly compacted of the rough fill topped with 3-4" of 3/4" crusher run stone (combination of 3/4 and fines) compacted is the best way to go. Also cutting concrete every 12' to prevent the slab from cracking is preferred.