6.3.2.3 The aggregate may be brought to and maintained in
a saturated condition, with surface moisture contained in
sufficiently small amounts to preclude loss by draining, at least
24 h prior to use. When this method is used, the moisture
content of the aggregate must be determined to permit calculation
of proper quantities of the damp aggregate. The quantity
of surface moisture present must be counted as a part of the
required amount of mixing water. Surface moisture in fine
aggregate may be determined in accordance with Test Methods
C 70 and C 566, making due allowance for the amount of water
absorbed. The method outlined here (moisture content slightly
exceeding absorption) is particularly useful for fine aggregate.
It is used less frequently for coarse aggregate because of the
difficulty of accurately determining the moisture content, but if
used, each size fraction must be handled separately to ensure
that the proper grading is obtained