I had a new concrete drive installed 4 months ago, which has dried with a blotchy appearance. The colour of the drive is uneven, and in places the surface has a sandy like appearance. Presently there doesn't appear to be any pitting, but I am concerned about the durability of the drive. I wonder if the concrete was incorrectly mixed when it was being laid resulting in this messy and sub-standard finish. I welcome your comments.

Get onto your contractor... sounds like they've done a poor job