We are building a new home and have a problem with the garage floor. In one area the top layer of the concrete is chipping. You can also see the area is darker .

What caused this problem and is there a fix that will last?

It was poured in May and the temperature that day was in the high 70's. The floor guy that did the work has the reputation as one of the best finishers in the area so I am surprised there is a problem.