The Swiss standard SN 640 432 Stone Mastic Asphalt surface layers which was published in 1996 is based especially on volumetric data with regard to testing of compliance. SMA subjected to testing of compliance according to SN 640 432 was never based on mechanical properties as it is required for asphalt concrete.

The European standard pre EN 227 104 which is still in preparation plans the Marshall test as well as the compaction with Gyratory apparatus for trial of the mix. Because Stone Mastic Asphalt surface layers, like all other surface layers on the road, are exposed to enormous mechanical stress the mechanical properties have to be checked in advance.

In this research project focus was put on whether the results of volumetric optimizing the SMA compacted either by Marshall or by Gyratory provide the same conclusions independent on the equipment used for compaction, i.e. finally is the Marshall test for trial suitable at all.