AS 2758.2-2009 pdf free download

AS 2758.2-2009 pdf free download.Aggregates and rock for engineering purposes Part 2: Aggregate for sprayed bituminous surfacing.
8.4 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.
9 DtRABILITY
9.1 General
Various authorities in Australia have adopted and developed test methods or sets of test methods for the assessment of the durability of aggregates. based on correlations between the obsered durability of aggregates in service and the results of their assessment procedures.
Each of these methods has been shown to be valid for a limited range of rock sources located primarily within the areas of control of the authority that uses a particular procedure. Certain supporting overseas data are available but climatic and use conditions may be ditTerent to the conditions experienced in Australia. Three sets of methods representing those most conimonly used in Australia are given in this Standard. Only one of these methods shall be included in the works specification. The chosen method should he the set which has been shown by local experience to be valid for rock sources likely to be used in the works.
NOTE: All of the available tests and associated specification limits attempt to ensure adequate durability in service by measuring a change in properties over a short period of lime (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 works specification shall include the assessment procedure considered most appropriate for that source.
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 9.2).
(b) Los Angeles value and sodium sulphate soundness (see Clause 9.3).AS 2758.2-2009 pdf free download.