This research reviewed the New Zealand vibrating hammer laboratory compaction test and energy standardisation thereof. The area of laboratory aggregate compaction was found to have significant problems with variability of results and reduced correlations with field compaction results, which suggests there are problems with standardisation of the compaction energies used.
A list of components of the New Zealand vibrating hammer test as it is actually performed in laboratories throughout New Zealand is provided, with each component introducing a larger or smaller amount of variability into the results. Methods of rectifying each component are identified to improve the standardisation of compaction energy and recommendations are made into how an alternative test method might be developed, tested and compared to the existing methods.
Keywords: compaction, compaction effort, compaction energy, granular materials, laboratory compaction, maximum dry density (MDD), optimal moisture content, vibrating hammer, vibrating table