AS 2758.2:2021 Aggregates and rock for engineering purposes Part 2: Specification for sealing aggregate.
6 Testing
Testing of aggregates shall be carried out in accordance with the relevant requirements of the applicable methods.
Laboratories that perform the tests outlined in this document shall meet the requirements of AS
ISO/IEC 17025.
The testing requirements and specified limits for all sealing aggregates are prescribed in Clauses 5 to 11.
NOTE A number of requirements in this document are fundamental and this specification provides a single test method and limits for these properties. Alternative test procedures and limits are presented for the determination of both shape and durability. For these properties, it is recommended that the test procedure and limits that are particular to the geographic area in which the aggregate source is located should be used in specifying supply.
7 Dimensional requirements
7.1 Grading requirements for aggregates
When determined in accordance with AS 1141.11.1 or AS 1141.1 1., each lot shall contorm to the grading envelopes given in Table 1.
7.4 Crushed particles of coarse aggregate
When determined in accordance with AS 1141.18, coarse aggregate that is derived from gravels or conglomerates shall consist of at least 75 % by mass of particles with at least two crushed faces.
NOTE With the exclusion of quarries in hard conglomerates, coarse aggregates derived from a hard rock quarrying process where all particles are crushed do not require testing.
8 Durability
8.1 General
Not more than one of the three sets of methods for the assessment of aggregate durability shall be specified. These sets of methods represent those most commonly used in Australia and are provided in this document. The set of methods specified should be the one which has been shown by local experience to be valid for rock sources likely to be used in the works.
NOTE All available tests and associated specification limits attempt to ensure adequate durability in service by measuring a change in properties over a short period of time (varying from minutes to days). This necessarily involves the imposition of conditions (e.g. loadings, temperature, exposure to reagents) that are unlikely to be met in service, in order to accelerate the change. Some aggregates may behave differently in service than predicted by a given durability testing regime. These differences arise from the different responses of the rock mineralogy and texture to the actual conditions. Experience with the material in service is essential in interpreting the testing results.
If aggregate is to be supplied from a source for which no experience is available with any of these assessment methods, the assessment procedure considered most appropriate for that source shall be specified. This decision will require some level of investigation before the appropriate procedure is determined.
The durability assessment method options require the use of one of the following sets of test methods:
(a) Wet strength and wet/dry strength variation (see Clause 8.2).
(b) Los Angeles value and sodium sulfate soundness (see Clause 8.3).
(c) Los Angeles value and unsound stone content (see Clause 8.4).AS 2758.2 pdf download.