To limit the probability that the use of inappropriate aggregate materials or the presence of an excessive proportion of contaminants in aggregates will lead to the premature failure of concrete under expected environmental or structural loads.
Where concrete supports or is used in 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.