Saturated-surface-dry

Saturated surface dry (SSD^{[citation needed]}) is defined as the condition of an aggregate in which the surfaces of the particles are "saturated" (i.e., surface adsorption would no longer take place), but the inter-particle voids are otherwise dry. In this condition aggregates will not affect the free water content of a composite material.

If the mass of an oven dried test sample (M_dry) is compared to the mass of a saturated-surface-dry (M_ssd) sample, the water adsorption (A) can be calculated:

$A = \frac{M_{ssd}-M_{dry}}{M_{dry}}$

See also

• Construction aggregate