Our concrete garage slab is chipping and breaking away at the edge where it meets the aggregate driveway, exposing rocks and gravel now. Our home is not even 4yrs old. How can we fix this problem and what would cause it. I think the driveway has sunk a bit, it seems slightly lower than the garage pad. Would this cause the problem, or do you think it was poured incorreclty in the first place. Any help would be great! Thanks.