AS 1141.54:2018 Methods for sampling and testing aggregates
5 APPARATUS
The following apparatus conforming to the provisions of AS 1141.2, is required.
(a) Balances—of sufficient capacity with a limit of performance not exceeding ±5 g for mass determinations >1 kg and ±0.5 g for mass determinations ±1 kg.
(b) Drying oven—capable of operating at 105°C to 110°C.
(c) Sample dividers or quartering equipment.
(d) Sieve—a 4.75 mm sieve.
(e) Dishes, trays and brushes.
6 PREPARATION
A test portion shall be prepared as follows:
(a) Obtain a sample of material using the appropriate procedure detailed in AS 1141.3.1.
(b) Obtain, either by quartering or by the use of a sample divider, a subsample containing at least 2 kg and not more than 5 kg retained on a 4.75 mm sieve.
(c) Handle in a manner that will avoid breaking up any clay lumps that may be present.
(d) Record the wet mass of the subsample (M w ).
(e) Remove all clay lumps and friable material from the subsample and record their mass (m c ).
(f) Dry the sub-sample to constant mass in the drying oven.
(g) Record the dry mass (M) of the sub-sample.
NOTE: If this test is performed in association with a particle size analysis, it is permissible to conduct a washed procedure in accordance to AS 1141.11.1 at this point and retain all sieve fraction retained on the 4.75 mm sieve as the test portion.
NOTE: The percentage of clay lumps is only an estimate because the clay will be at a higher moisture content compared with the moisture content of the subsample. The percentage clay lumps will be overestimated. If necessary, the procedures of AS 1141.32 may be followed on a separate subsample for a more accurate determination. If desired, the dry mass of the clay lumps may be estimated by determining the moisture content of the subsample and adjusting C above for moisture.