Question

On concrete thickness up to about seven inches, which of the below are true about air content to slump?

1) Air content increases as slump decreases
2) Air content decreases as slump increases
3) Air content decreases as slump decreases
4) Air content increases as slump increases

Answer 1

The air content in concrete generally increases as the slump decreases and decreases as the slump increases.

Step-by-step explanation:

In general, air content and slump in concrete have an inverse relationship.

As the slump decreases, meaning the concrete becomes stiffer and less flowable, the air content tends to increase. This is because less workability in the concrete mixture can cause an increase in air entrainment, which means more air gets trapped in the mix.

On the other hand, as the slump increases and the concrete becomes more fluid, the air content tends to decrease since there is less air entrainment.