The Austroads Member Authorities (AMAs) in Australia and New Zealand are developing a performance-based approach to the specification of unbound granular materials. There has been a general agreement to adopt the engineering properties related to workability and performance for performance-based specification of granular pavement layers. There has also been consensus among AMAs on the use of the repeated load triaxial test as the best candidate laboratory performance test to pursue new material performance measures (such as shear strength, resilient modulus and pavement layer deformation). This paper provides a review of current AMAs pavement material specifications, their origins, strengths and weaknesses. In addition, it examines the issues in the development of performance-based specifications for unbound granular materials as well as the benefits to be gained from the implementation of 'performance-based' material specifications. Areas in the performance-based specifications that require refinement and verification are identified and further research in these areas is recommended. (a).
Abstract