Page 56 - bukuneutron

ment can be ready instantly, this is main advantageous
using nuclear gauge compared with conventional method.

In fact it has been shown that radioisotope mois-
ture gauges is faster between 5 and 15 times as many
tests can be carried out per man-hour. In Malaysia,
radioisotope gauges are specified in the constructor’ s
contract as the method to be used in checking com-
paction and it should be only a matter of time before
these instruments are universally accepted for this pur-
pose. The system has been used to determine the
number of passes for optimum compaction for different
types of compacting equipment on various soils and
on asphalt. Measurements can be made on steep em-
bankments, vertical surfaces and on materials such as
dry sand and coarse gravel where conventional meth-
ods are inaccurate.

The appearance and strength of soils are strongly
dependent on grain size, density and water content.
The content of water is represent with value of mois-
ture or humidity in the soil. From these basic proper-
ties the values of plasticity, deformability, shear resis-
tance and permeability may be calculated. These data
can be obtained from a knowledge of bulk density and
moisture content and are necessary to achieve the re-
quired structure stability. Neutron moisture gauge and
gamma density gauge are usually implemented in de-
termination of these data. However, gamma density
gauge is not the scope of this book.

43