Concrete Corner

Ready mix concrete grades can be confusing if you are not a builder or engineer. The grade tells you the compressive strength of the cured concrete, measured in newtons per square millimetre. A C30 mix, for example, reaches 30 newtons per square millimetre after 28 days. That number matters because it determines whether the concrete can handle the load you are putting on it. Pick too low a grade and the slab cracks under weight. Pick too high a grade and you pay for strength