Circular driveways are not very commonly used but are very easy to make. First of all, you will need to make a circle with wood. Make sure that the radius is exactly the same throughout the whole circle. After that, put wire in the ground. After you've place wire, throw the cement on top of it. Compact it extremely well to avoid cracks in the future. Then, wait a couple of hours and you're done.
. However, you should know that it takes 28 days for concrete to achieve its maximum strength. Simply water the drive way everyday and you'll be good.