Figure 13-17.—Items required for testing sand for organic matter.
aggregate and the percentage of absorption are as
follows:
1. Dry a representative sample of the aggregate
(approximately 5,000 grams) to a constant weight at
110°C. Then cool the sample for 1 to 3 hours, immerse
it in water, and allow it to soak for about 24 hours.
2. Remove the sample from the water and dry it to
a saturated, surface-dry condition by rolling the sample
in an absorbent cloth until visible films of water are
removed and the particle surfaces appear slightly damp.
3. Weigh the sample in the SSD condition and
record the weight to the nearest 0.5 gram. Then
immediately place the sample into a container or wire
basket and determine its immersed weight (or weight in
water) at 23°C. Be sure that any entrapped air is
removed by shaking the container or basket while it is
immersed. Record the immersed weight to the nearest
0.5 gram.
4. Dry the sample to a constant weight at 110°C,
cool it for 1 to 3 hours, and then weigh the oven-dried
sample. Record the weight to the nearest 0.5 gram.
5. The bulk specific gravity (SSD condition) and
the percentage of absorption can now be calculated
using the following formulas:
And:
Where:
A
=
B =
C =
weight of oven-dried sample in air (in
grams)
weight of SSD sample in air (in grams)
immersed weight of saturated sample (in
grams)
Specific Gravity and Absorption, Fine Aggregate
(ASTM C 128).— The procedures for determining the
bulk specific gravity of the fine aggregate in a SSD
condition and the percentage of absorption are as
follows:
1. Dry a representative sample of the fine
aggregate (about 1,000 grams) to a constant weight at
110°C. Then cool the sample, immerse it in water, and
allow it to soak for about 24 hours.
2. After the soaking is completed, spread the
sample on a flat, nonabsorbent surface and stir it to
obtain uniform drying. Continue drying the sample until
it approaches a SSD condition.
13-25
