POZZOLANIC EFFECT OF RICE HUSK ASH IN PASTE

The research of this final year project is to investigate the pozzolanic effect of rice husk
ash in the cement/binder paste. In order to attain this main objective, there are several
tasks need to be carried out. In other word, there are several sub-objectives need to be
attained to achieve the mainobjective of this research. Thesub-objectives of this research
will be discussed clearly in the introduction.

The production of rice husk ash is the main topic concerning in this research. Rice
husk ash produced must fulfill two basic requirements, the ash must contain at least 80%
of silica and it must attain amorphous phase so that the ash is chemical reactive in the
mixture. Thus, the high quality ash can be obtained by controlling the burning process of
the rice husk. A standard burning procedure had been fixed and the detail of the burning
procedure is discussed in detail inthe methodology section.
The fines of the rice husk ash will be determined by using Blaine Air Permeability
test and Le Chatelier flask test. However, the equipment of Le Chatelier flask is not
available in the university. Thus, the test had to be carried out by using ordinary conical
flask. The concept and procedure for Le Chatelier Flask test will maintain the same for
ordinary conical flask testbutthe result obtained for LeChatelier Flask test will be more
accurate than the ordinary conical flask due to the different equipment calibration
between both tests.
Water/cement-binder ratio is supposed determining by using the flow tablet but
due to unavailability of flow table in the university, Vicat test had been chosen to
determine the water/cement-binder ratio. The water/cement-binder ratio is maintained
constant previously in this research but the selected water/cement-binder ratio is not
suitable for all the mixtures especially mixtures that incorporate higher percentage of
RHA. Therefore, water/cement-binder ratio for all the mixtures will be determined by
carrying out the Vicat test to ensure that the mixtures will undergo complete hydration
process. Thus, we had fixed one water/cement-binder ratio for every mixture, but one value of W/C ratio for each mixture cannot be justified as the optimum W/C ratio that
gives the optimum compressive strength for the each mixture. Thus, we choose a few
more water/cement-binder ratio for each mixture so that we can obtain a curve that will
give theoptimum compressive strength for all the mixtures.
The degree of hydration of the paste can be obtained by carrying outthe TGA test.
The paste at the age of 28 days will be grinded and will be tested in the TGA machine.
Since there are a lot samples to be tested, the optimum compressive strength for each
samples will be chosento undergothe TGAtest.