AASHTO T11 / ASTM C117 Material Finer than No 200 Sieve

Standard Method of Test for Materials Finer Than 75 microns, No. 200 SIEVE IN MINERAL AGGREGATES BY WASHING.

AASHTO Designation T 11 and ASTM Designation C 117

SIGNIFICANCE AND USE.

Material finer than the 75 microns number 200 sieve
can be separated from larger particles much more
efficiently and completely by wet sieving than through
the use of dry sieving. Therefore, when accurate
determinations of material finer than 75 microns in
fine or coarse aggregate are desired, this test method
is used on the sample prior to dry sieving in accordance
with T 27. The results of this test method are included
in the calculation in T 27, and the total amount of
material finer than 75 microns by washing,
plus that obtained by dry sieving the same sample,
is reported with the results of T 27.
Usually, the additional amount of material finer
than 75 microns obtained in the dry-sieving process
is a small amount.
If it is large,
the efficiency of the washing operation should be checked.
A large amount of material could also be an indication
of the degradation of the aggregate.

SAMPLES.

If the same test sample is to be tested
for sieve analysis according to T 27,
comply with the applicable requirements of that method.
Otherwise, the mass of the test sample, after drying,
shall conform with the following:

APPARATUS AND MATERIALS.
Balance,
Sieves 1.18 mm number 16 and 75 microns number 200,
Oven, capable of maintaining a uniform temperature of 110 ± 5°C,
and Pan.

PROCEDURE -WASHING WITH PLAIN WATER.
Dry the test sample to constant mass
at a temperature of 110 ± 5°C.
Determine the mass to the nearest 0.1 percent of the mass of the test sample.
Place the test sample in the container large enough to permit vigorous agitation without spilling when water is added.
Add water and agitate.
Pour the wash water containing the suspended and dissolved solids over the nested sieves, arranged with the coarser sieve on top, avoiding decantation of coarse particles. Add a second charge of water to the sample in the container, agitate, and decant as before. Repeat this operation until the wash water is clear.

Return all material retained on the nested sieves by flushing to the washed sample.

Dry the washed aggregate to constant mass at a temperature of 110 ± 5°C and determine the mass to the nearest 0.1 percent of the original mass of the sample.

CALCULATION.

percentage of material finer than number 200 sieve is equal to original dry mass of sample minus dry mass of sample after washing divided by original dry mass of sample times 100

Report the percentage of material finer than the number 200 sieve by washing to the nearest 0.1 percent, except if the result is 10 percent or more, report the percentage to the nearest whole number.