Sentence 9.3.1.7.(2)

Intent 1:

To limit the probability that the concrete will not flow around the aggregate in the typically thin wall and slab sections used in Part 9 buildings, which could lead to aggregate segregation, which could lead to:

• reduced compressive strength,
• increased shrinkage and cracking, or
• low resistance to air and moisture transfer.

This is to limit the probability of:

• spalling,
• inadequate performance, or
• 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.