Self healing concrete crack by using pulverized fuel ash (PFA) as cement replacement material

Nowadays the high demand of cement is an indication of development especially
for the construction industry. Therefore, it is needed an alternative way in fulfill this
situation. Many researches were developed in order to find suitable material to be used
as a replacement for cement such as palm oil fuel ash and pulverized fuel ash.
Pulverized fuel ash can be used as a partial replacement material in cement composition
and this material has pozzolana effect that can generate the self healing process. Self
healing is an autogenous healing of cracks in concrete is showed by the formation of
calcite in the crack. In this study, by product of coal combustion power plant from
Tanjung Bin, Johore namely pulverized fuel ash (PFA), was used as the partial
replacement in cement in order to study the effectiveness of PFA toward self healing in
concrete crack. The ultrasonic pulse velocity (UPV) and compressive strength test were
conducted to determine the ability of self healing of concrete containing PFA. The result
shows that 20 % of PFA (PFA-20) is the best percentages of cement replacement and
water curing was the best mechanism to heal the hairline crack in concrete.