Disclaimer
Test limits listed in this Appendix are provided to illustrate the relationships between material characteristics. Although the limits outlined have been used in some specifications, they are intended as a guide only and are not intended to be adopted nationally.
B.1 Quality System
The supplier shall establish implement and maintain a Quality System in accordance with the requirements of AS/NZS ISO 9001 or a recognised equivalent.
B.2 Test Methods
All testing required by the specification shall be performed in a laboratory endorsed by the National Association of Testing Authorities (NATA). Tests shall be performed in accordance with the
relevant Australian Standard testing procedures.
B.3 Materials
Crushed rock fragments shall consist of clean, hard, durable, angular rock fragments of uniform quality. The use of sands and/or filler and crushed fines from a source other than the source of the coarse aggregate is permitted, but shall be subject to approval of the purchaser.
For the purpose of this specification crushed rock is to be supplied in various in classes broadly defined as follows:
Class 1 is normally specified as a premium cohesive pavement base material for unbound pavements where a very high standard of surface preparation for a sprayed sealed or thin asphalt surfacing is required. It has a minimum plasticity index requirement and may have additional requirement for maximum permeability when used for heavy duty unbound pavements.
Class 2 is normally specified as a high quality pavement base material for unbound flexible pavements in locations where a very high standard of surface preparation may not be required. Class 2 crushed rock does not have a minimum plasticity index or a maximum permeability requirement.
Class 3 is normally specified as a high quality upper subbase material for heavy duty unbound flexible pavements. It may have a minimum permeability requirement to provide positive drainage to the sub-surface drains.
Class 4 is normally specified as a lower subbase material for heavy duty pavements or a subbase material for most other types of pavements. It may have a maximum permeability requirement if used as a capping material.
B.4 Source Rock Specifications
The supplier shall supply details of the source and geological description of the rock to be used for production of the crushed rock.
B.4.1 Coarse Aggregate Fraction (Portion Retained on a 4.75 mm AS Sieve) Tables B.1, B.2 and B.3 provide three alternative combinations of durability and hardness
requirements. Only one combination shall be applied and this must be selected by the purchaser.
This should be the set that has been shown by local experience to be valid for the rock sources likely to be used. Materials from sources not complying with the given values may perform satisfactorily and may be used provided that there is local evidence of proven performance.
B.4.2 Wet Strength and Wet/Dry Strength Variation
Base and subbase materials having wet strength and wet/dry strength variation values that comply with the limits given in Table B.2 have performed successfully in practice.
B.4.3 Los Angeles Value and Unsound and Marginal Stone Content
Base and subbase materials having a Los Angeles Value not greater than the relevant limits given in Table B.3, when tested in accordance with AS 1141.23, have performed successfully in practice.
In addition, base and subbase materials having unsound and marginal stone content not greater than the relevant limits given in Table B.3, when determined in accordance with AS 1141.30, have also been used successfully.
B.4.4 Los Angeles Value and Sodium Sulphate Soundness Loss
Base and subbase materials having a Los Angeles Value not greater than the relevant limits given in Table B.4, when tested in accordance with AS 1141.23, have performed successfully in practice.
In addition, base and subbase materials having a sodium sulphate soundness loss not greater than the relevant limits given in Table B.4, when determined in accordance with AS 1141.24, have also been used successfully.
Table B.1: Wet strength and wet/dry strength variation requirements for hardness and durability
Test value
Test Property Base Subbase
Class 1 Class 2 Class 3 Class 4 (lower)
10% fines value (wet) (kN) (min) 100 80 50 –
wet/dry strength variation (%) (max) 35 35 45 –
Table B.2: Los Angeles value and unsound and marginal stone content requirements for hardness and durability Test value
Base Subbase
Test Rock type
Class 1 Class 2 Class 3 Class 4
coarse grained 35 35 40 –
Los Angeles value (%) (max)
fine grained 30 30 35 –
total of marginal and unsound stone (%)
(max) all rock types 10 10 20 –
unsound stone (%) (max) all rock types 5 5 10 –
Table B.3: Los Angeles value and aggregate soundness requirements for hardness and durability
Los Angeles value (%) (max)
fine grained 30 30 35 –
Sodium sulphate soundness
(maximum weighted average loss) (%) all rock types 6 9 12 –
B.4.5 Fine Fraction (Portion Passing a 4.75 mm AS Sieve)
The use of crushed fines produced from a quarry, or a location within a quarry, different from that used for the production of that fraction of the crushed rock retained on the 4.75 mm AS sieve is permitted subject to the approval of the purchaser. Such crusher fines produced from any igneous or metamorphic rock when tested in accordance with AS 1141.25.3 shall have a Degradation Factor-Fine Aggregate value not less than 60.
The use of sands and/or filler is permitted subject to approval in writing by the purchaser as to the proposed source and nature of such materials, the proposed amounts to be added and the
proposed method of incorporating such materials in the product. Where the supplier elects to use an additive component with the crushed rock, the additive shall:
be derived from sound and durable material
not be cementitious in nature
be free of vegetable matter, lumps and balls of clay and oversize particles of rock
be sized such that it can be effectively and uniformly distributed throughout the crushed rock
be kept dry to facilitate incorporation into the mixture
be blended in the base and subbase finished products and shall not be greater than 15% by mass.
B.5 Product Specifications
The crushed rock shall be free from vegetable matter and lumps or balls of clay and shall comply with the relevant requirements of Table B.4.
Table B.4: Product requirements
Test Test values
(1) Minimum value for PI specified to ensure the material is sufficiently impermeable to resist penetration of water through thin surfacing layers.
(2) Value applicable to material passing 19.0 mm sieve: compacted at Optimum Moisture Content to 98% of Modified Maximum Dry Density as determined by test;
then soaked for 4 days prior to CBR testing.
(3) Applicable to crushed river gravels.
B.5.1 Sulphide Mineralisation
Unless otherwise approved by the purchaser, crushed rock produced from any source shall not be permitted if that fraction of the crushed rock product passing the 2.36 mm AS sieve, when
prepared according to AS 1289.1 Clause 4.6, fails to comply with the requirements of Table B.5.
Table B.5: Requirements for sulphide mineralisation
Test Test value Soil to water ratio
pH (units) 6.0 (min) 1:2.5
conductivity (mS/cm) 1500 (max) 1:1
B.5.2 Grading of Crushed Rock Base and Subbase
The grading of the crushed rock after compaction shall comply with the relevant requirements of Tables B.6, B.7, B.8 and B.9.
Table B.6: Grading requirements for Class 1 & 2, 20 mm base Test value
Table B.7: Grading requirements for Class 3, 20 mm subbase AS sieve size (mm) Target grading
(% Passing)
Test value limits of grading (% Passing)
Table B.8: Grading requirements for Class 3, 40 mm subbase AS sieve size (mm) Target grading
(% Passing) Test value limits of grading (% Passing)
Class 4 crushed rock subbase shall comply with the relevant nominal size grading requirements given in Table B.9. The crushed rock shall not be graded from near the coarse limit on one sieve to near the fine limit on the following sieve or vice versa.
Table B.9: Grading requirements for Class 4 subbase Test Value Limits of Grading (% Passing) AS Sieve
Where payment is to be made on a mass basis, the average moisture content of the crushed rock at the plant shall not exceed 3.5% by mass unless otherwise specified or unless the contractor has, at the time of tendering, nominated an upper limit of average moisture content greater than 3.5%. In the latter case the difference between the nominated value and the specified value will be taken into account when tenders are being considered. The average moisture content of crushed rock supplied on any one day will be determined from three samples taken at random from that day’s supply. If the average moisture content is greater than that specified or nominated, the material may be rejected. If, at the discretion of the purchaser, the material is accepted, then payment will be made for the mass determined by deducting the calculated mass of excess moisture from the net mass shown on the delivery dockets.
B.7 Stockpiling Prior to Delivery
Material may be stockpiled prior to delivery provided the following requirements are fulfilled:
the product, after recovery from the stockpile, complies with this specification
the stockpile site is clean, adequately paved, and well drained
if a stockpile is constructed in more than one layer, then each layer is fully contained within the area occupied by the upper surface of the preceding layer
the stockpiled material shall have a minimum moisture content of 3.5% to prevent segregation and excessive dust.
B.8 Handling of Materials
Handling of materials, including the loading of trucks and stockpiling, shall be effected in such a manner as to minimise segregation.