It's usually measured in MPa, megapascals, to determine strength for compression most of the time. There are different grades, from 20 to 50 MPa until high efficiency with more than 125 Mpa. It's a matter of selecting the right conditions and recipe of materials.
The difference between concrete comes very significantly at the resistance in which the material develop cracks and when they connect to produce more serious issues. With a low grade concrete, cracks could appear with approximately 40% of compressive stress and connect cracks with 80% or a bit more. This is not what happens with high strength concrete, the one used to special constructions for instance like bridges or tall buildings.
While steel experiences deformation, concrete, once its strength is surpassed, breaks like crystal making the structure unusable. Fortunately it almost doesn't experience thermal deformation and at the same time the expected durability is in the order of centuries, even if the expected lifetime of the project goes for 50 or 100 years.
Did you know that concrete can be polished? It's an amazing option to create beauty and resistance. For a floor, a nice option!