Compaction in the soil can be done in three methods. Corresponding to these, the various compacting equipment’s can be grouped under three categories:
1. Rollers
2. Rammers
3. Vibrators
1. Rollers:
The rolling equipment’s are of 3 types:
Smooth wheeled rollers- 20-180KN-used satisfactorily on moderately cohesive soils.
Pneumatic type rollers: pressure ranging from 400-1050KN/m2- cohesion less sand and gravels and on cohesive soils.
Sheep foot rollers: pressure ranging from 800-3500KN/m2-cohesive. soils but not coarse grained cohesive soils.
2. Rammers:
Ramming equipment consists of 3 types:
Dropping weight type.
Internal combustion type-weighing upto 1 tonne.
Pneumatic type- weighing from 300-1500N.
These are used for compacting soils in confined places.
3. Vibrator:
A vibrator consists of a vibrating unit of either the out of balance weight or a pulsating hydraulic type mounted on a screed, plate or roller. Vibratory rollers are useful for cohesion less soils.
I like that you said that pneumatic vibrators are useful for cohesion-less soils. This reminded me of construction projects where excess moisture and pockets of air from freshly poured concrete must be removed. I could imagine how vibrating tables could play a big role in different industries.