To limit the probability that an inadequate resistance to sulphate salts in the soil will lead to the inadequate performance or the premature failure of concrete under expected environmental or structural loads.
Where concrete is used in footings for chimneys or fireplaces, this is to limit the probability of the compromised integrity of the chimney or fireplace, which could lead to the ignition of combustible building components.
This is to limit the probability of harm to persons.