We built a home almost one year ago and recently I've noticed small hairline cracks developing in our three car garage slab. It's a very large monolithic pour. I also noticed that no control joints were cut in the concrete. When I spoke to the contractor, he admitted that it was a mistake and offered to do whatever to make amends, including making saw cuts. My guess is that the cracks are from shrinkage and that making cuts at this point almost a year later would do little good and could possibly add to the problem. What, if anything, can be done at this point? I believe that compaction is good but I don't think there's any rebar in the slab, either.