AS 1141.12:2015 Methods for sampling and testing aggregates
6 TEST PORTION
The minimum mass of the test portion shall be determined by the nominal size of the aggregate in accordance with Table 1. The test portion required shall be obtained by sample division and no attempt shall be made to secure an exact predetermined mass.
NOTE: Where possible, the test portion should be prepared from a sample obtained in accordance with AS 1141.3.1.
7 PROCEDURE
The procedure shall be as follows:
(a) Dry the test portion to constant mass (see AS 1141.1) and determine its mass (m 1 ).
(b) Place the dried test portion in a dish or pan and add sufficient clean potable water to cover it. For materials that contain clay, a dispersing agent that does not react with the test portion may be used.
NOTE: 5 mm aggregate, fine aggregates and fillers may be washed directly on the washing sieve or the 75 μm sieve, provided that the mesh is not overloaded (see Table 2 of AS 1141.11.1).
(c) Vigorously agitate the contents without spilling the water to take the fine material into suspension and immediately pour the wash water through the pair of sieves nested together with the 1.18 mm sieve at the top. Avoid, as far as possible, decantation of the coarse particles of the test portion. Return the material retained on the sieves to the test portions.
(d) Continue agitation and washing until the water is clear in the pan and passing through the sieves. NOTE: Where the amount of material finer than 2 μm is to be determined, retain the wash water for use in AS 1141.13.
(e) Dry the washed aggregate to constant mass and determine the mass (m 2 ) of dried aggregate.
9 REPORT
The following shall be reported:
(a) The percentage passing the 75 μm sieve to the nearest whole number.
(b) The method of drying, if other than by the oven at 105°C to 110°C.
(c) The number of this Standard, i.e. AS 1141.12.