The effect of ultrafine palm oil fuel ash (UPOFA) on chloride resistance of concrete

In conjunction with the rapid development of palm oil industry, huge amount of waste
generated which end up in landfill and extra cost paid to reduce its impact on our
environment. Among the waste, the palm oil fuel ash (POFA) is well known as it
contains pozzolanic property that has potential to promote the performance of concrete.
Many researches had been carried out to study the mechanical performance of concrete
containing POFA. In this study, the ultrafine palm oil fuel ash (UPOFA) was utilised in
order to know its effect on the basic mechanical properties and corrosion resistance of
blended concrete. The POFA was ground to reach median size of about
5
gm. Four mix
of concrete was prepared by partially replacing 0 %, 10 %, 20 % and 30 % of Ordinary
Portland Cement with UPOFA. All specimens were water cured for at least 28 days in
water curing tank before subjected to lab tests. The specimens were tested for
compressive strength, porosity and chloride resistance property through accelerated test
and salt ponding. The accelerated chloride test employed was impressed voltage test,
half-cell potential. Based on the test result, the concrete with 30 % of UPOFA content
show better compressive strength, lower porosity and longer time to crack. It is found
that the concrete with partial replacement of 30 % UPOFA to concrete also delays the
corrosion to happen on steel bar through half-cell potential test. Besides, the concrete
containing 30 % UPOFA as partial cement replacement shows lowest free and total
chloride content at depth of 21 mm to
25
mm in concrete as compared to other
specimen. From this study, the concrete with 30 % of UPOFA as partial cement
replacement material shows the best basic mechanical property and chloride resistance.