Measured Aggregate Absorption (at Set)

The ‘at set’ absorption should be entered on the Laboratory Measurements Dialog for each sieve size of the fine and coarse aggregate.

The ‘at set’ absorption is the percentage by weight of the water, which the aggregate would lose if dried in its condition at the time of the setting of the concrete. The percentage is equal to

100(Watset – Wdry)/Wdry

where:

Watset = weight of given quantity of aggregate in the ‘at set’ condition.

Wdry = weight of same quantity of dry aggregate.

If the measured aggregate density has been set for the saturated, surface-dry (SSD) condition, Firstmix assumes that the absorption in the SSD condition is equal to the ‘at set’ absorption.