AASHTO T 11:2005(2013) Standard Method of Test for Materials Finer Than 75-um (No.200) Sieve in Mineral Aggregates by Washing.
Material finer than the 75-pm (No. 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 pm in fine or coarse aggregate arc desired, this test method is used on the sample prior to dry sieving in accordance with T 27. The results of this test method arc included in the calculation in T 27, and the total amount of material finer than 75 pm 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 pm 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.
4.2. Plain water is adequate to separate the material finer than 75 pm from the coarser material with most aggregates. In some cases, the finer material is adhering to the larger particles, such as some clay coatings and coatings on aggregates that have been extracted from bituminous mixtures. In these cases, the fine material will be separated more readily with a wetting agent in the water.
Balance—The balance shall have sufficient capacity, be readable to 0.1 percent of the sample mass, or better, and conform to the requirements of M 231.
5.2. Sieves—A nest of two sieves, the lower being a 75-pm (No. 200) sieve and the upper being a sieve with openings in the range of 2.36mm (No. 8) to 1.18 mm (No. 16), both conforming to the requirement of M 92.
5.3. Container—A pan or vessel of a size sufficient to contain the sample covered with water and to permit vigorous agitation without loss of any part of the sample or water.
5.4. Oven—An oven of sufficient size, capable of maintaining a uniform temperature of 110 ± 5°C (230 ± 9°F).
5.5. Wetting Agent—Any dispersing agent, such as liquid dishwashing detergents, that will promote separation of the fine materials.
Note 1—The use of a mechanical apparatus to perform the washing operation is not precluded, provided the results are consistent with those obtained using manual operations. The use of some mechanical washing equipment with some samples may cause degradation of the sample.
6.1 Sample the aggregate in accordance with T 2. If the same test sample is to be tested for sieve analysis according to T 27, comply with the applicable requirements of that method.
6.2. Thoroughly mix the sample of aggregate to be tested and reduce the quantity to an amount suitable for testing using the applicable methods described in T 248. If the same test sample is to be tested according to T 27, the minimum mass shall be as described in the applicable sections of that method. Otherwise, the mass of the test sample, after drying, shall conform with the following.AASHTO T 11 pdf download.