Concrete undersoil filler?

Question

Looking to do a project, replace a 11x21 garage slab from original 20x21 . Trying to keep it in budget, can’t afford to do $300+ of abc. Next best thing? 

Update:

Kind of need it tomorrow. 🙄

Answer 1

NOT doing the job at all is better than not doing it RIGHT. In fact, you absolutely can't afford to do it wrong.