I have a concrete question?

i mixed some concrete for a garage floor slab that would be exposed to freezing and thawing using GU cement. For the test i used about 10 kg cement, 4 kg water, 26 kg coarse and 12 kg fine. my slump was 107, my air was 7. the 28 day break came out with 39 mpa.... is this to strong? what would be the problems with this conrete if any?