I had a couple tree stumps removed, including following and digging out surface roots to a depth of two feet and a distance of about 15 feet from the stumps. Now that area is going to get the concrete slab that the trees broke up replaced. The soil is adobe, this is in Hollywood, CA.
What should I do to compact the soil before pouring the new concrete? Do I need to dig it out, and run a whacker machine over it in layers? Is it good enough just to run a whacker over the existing surface?