Frequently Asked Questions
Q: What is meant by "saturated surface dry condition" of aggregates?
A: Saturated Surface Dry describes
the condition of the aggregate in which the pores in each particle
of the aggregate particle are filled with water and no excess water
is on the particle surface. This allows the absorption and the specific
gravity of the aggregate to be measured. Moisture content of aggregate
is described by four categories:
The following are examples of how the moisture content of an aggregate affects
the mixture proportioning of concrete:
Example 1: If an aggregate had zero moisture content
and an absorption value of 2%, then the water added to the concrete
mixture would be increased by 2% of the weight of the aggregate
to achieve the desired water cement ratio.
Example 2: If an aggregate had a 6% moisture content
and an absorption value of 2% then the water for the concrete mixture
would be decreased by 6% - 2% = 4% times the weight of the aggregate
to maintain the desired water cement ratio.