An ideal compacted soil provides the best bearing capacity. This is arrived by the power and the frequency of load cycles on the one hand. But it needs an optimal water content to achieve high density in soil compaction on the other hand. Proctor equipment is designed to proof the relation between compaction and water content. It consists of a load piston with drop weight, which can be risen manually or automatically by a friction disk. Soil samples of the same weight but with different water content are uniformly compacted to distinguish the final density.

 

The correlation between water content and density is a parabolic function with the ideal soil compaction at its peak. The test procedure is standardized in the Standards DIN 18127; EN 13286-2; ASTM D558, D560, D698, D1557.

 

With a Gyratory compactor higher density can be achieved as with proctor compactor. In contrast, a given load is put on the sample surface of a rotating pot. This leads to a denser compaction by extensive work in a gyratory compactor.

 

The compacted samples (like marshal compaction) are used for further soil mechanical examination: shear tests, consolidation tests, triaxial tests, CBR-tests, permeability tests and many more.