| The
Clegg Impact Soil Tester provides a means for
measuring and controlling soil strength and
consolidation levels during trench re-instatement.
It is also used to confirm uniform compaction of
over wide areas of ground, identifying poorly
compacted areas and ineffective rolling of
materials. The most popular Clegg instrument is
one using a 4.5 Kg hammer [shown
below].
The
Tester consists of a compaction hammer operating
within a vertical guide tube. When the hammer is
released from a fixed height it falls through the
tube and strikes the surface under test,
decelerating at a rate determined by the stiffness
of the material within the region of impact. A
precision accelerometer mounted on the hammer
feeds its output to a hand held digital readout
unit which registers the deceleration in units of
Impact Value (IV). The IV indicates soil strength
and shows good correlation with CBR test
results.
To see a
correlation to the Clegg Hammer and a CBR
click here
What is a CBR
click here
| 
