This Standard provides designers and specifiers with a basis for developing the criteria for selection of natural, boulder-sized rock materials for use as armourstone on sea walls, harbour and river foreshores or dam walls. Armourstone boulders range from several kilograms up to many tonnes in mass. Dimensions of the armourstone may be the defining design requirement.

APPLICATION

These guidelines may form the basis of a works specification but cannot be used as a specification in themselves. The designer or specifier is presented with a series of considerations and alternative criteria from which to structure a project specification; however, the criteria are deliberately conservative and may not be cost effective in some instances. The designer is in the position to determine whether criteria suggested apply to the project under consideration and whether the project environment would allow relaxation of suggested criteria.

The selection of test procedures and test limits will be determined by the design philosophy and the design life of the completed structure. For the purposes of these guidelines a design life of 40 years has been assumed. For many structures, where replacement of materials is practical, much shorter design life cycles may be appropriate and lesser criteria may be successfully applied to the armourstone. For structures such as dams, a much longer design life may be required and the criteria will need to be adjusted accordingly.

The works specification should specify all the tests and the limits appropriate to the design application; however a distinction may be made between those requirements used for selection and evaluation of the source material and those requirements used for quality control of product during the execution of a supply contract. It may not be necessary to apply the full range of tests during the execution of the contract. The frequency of testing should be detailed in the works specification.

For legal purposes, only the works specification is binding and this document has no legal significance for contract purposes.