Compaction adopted in the field
A hand operated tamper consists of block iron, about 3 to 5 Kg mass, a ttached to a wooden rod. The tamper is lifted for about 0.30m and dropped on the soil to be compressed. Mechanical Tampers operatted by compressed air or gasoline power.
a) smooth - wheel rollers
b) pneumatic - tyred rollers
c) Sheep- foot rollers.
a) Smooth - wheel rollers
Smooth - wheel rollers ar e useful finishing operations after compaction of fillers and for compacting granular base causes of highways.
b) Pnumatic - tyred roller s
Pneumatic - tyred rollers u se compressed air to develop the required in flation pressure.The roller compactive the soil primarily by kneading action. These rolle srs are effecting for compacting cohesive as we ll as cohesion less soils.
c) Sheep - foot rollers
The sheep - foot roller con sists of a hollow drum with a large number of small projections (known as feet) on its surf ace. The drums are mounted on a steel frame. The drum can fill with water or ballast incre ases the mass. The contact pressure is gener ally between 700 to 4200 KN/m2.