Bentonite Amended Fly Ash for Environmental Hydraulic Barrier

The objectives of this study is to conduct compaction tests, hydraulic conductivity tests,
and shear strength tests on fly ash with and without kaolinite clay mixed at various
fraction. The project requires student to study the utilizing of fly ash, with kaolinite, a
type of Bentonite clay for purpose of making the environmental hydraulic barrier. The
study is aimed to fmd the alternate markets for re-use of the waste material (fly ash).
To achieve the project objective, the compaction and hydraulic conductivity tests have
been conducted. However due to time constraint, shear strength test could not
conducted. The fly ash used for this project is provided by TNB Jana Manjung Power
Plant. Before the experiment started, the fraction of fly ash added with kaolinite is set so
that the results can be varied. Compaction and permeability test is conducted with the
same fraction so that the results from two experiments can be differentiated. The scopes
of the study are to study the characteristics of the fly ash and clay, conducted the tests
and analyze the outcome. From compaction tests results, the dry density-moisture
content curve is constructed where the maximum dry density and optimum moisture
content is obtained. From the curve constructed the results shows that sample of 100%
fly ash gives the highest maximum dry density. In order to conclude the best fraction
obtained the sample with highest dry density and lowest optimum moisture content is
analyzed. As for the permeability tests, the value of hydraulic conductivity is calculated
and it is vary as the fraction of sample vary. The hydraulic conductivity is decreasing as
the fraction of fly ash decreasing. But from the results, it is shown that fly ash is
suitable to reduce the conductivity of clay. As the conclusions, the fly ash can possibly
be the environmental hydraulic barrier but further tests has to be conducted to get an
accurate results and additional elements could be added to improve the characteristics of
the sample.