I have just completed a research project into modified compaction methods for testing soils and capping materials with up to 10%> 90mm (BS 1377-4 limits are not more than 10% > 37.5mm). The project related to options for modifying the material or the compaction method, and what the likely effects would be. In UK many fill materials need to be placed at MC range close to OMC, but normal methods limit size of material. If this is of interest, let me know and I can expand on this