What concrete strength is normally used for residential applications, low rise buildings, paving and driveways?
All pre-mixed concrete suppliers have standard concrete strengths of 20MPa, 25MPa and very often, 32MPa which is reached after 28 days of curing and is more than suitable for all residential applications.
Sometimes we are asked if a higher strength should be used for the garage area. This is not really necessary. Usually the biggest load on a slab is absorbed by the sub grade and not the structure on top of it.