4. Conclusions
Based on the investigation carried out on utilizing POFA as
partial cement replacement in OPSC, the following conclusions can
be drawn:
a. The slump and compaction factor values were improved when
10% and 15% of POFA replacement levels were adopted while
further increase to 20% and 25% POFA replacement levels
reduced these properties.
b. The effect of POFA was minimal in terms of Vebe time and air
content of the fresh OPSC mixes.
c. Early age strength of POFA-blended OPSC was lower compared
to the OPSC without POFA; however, the strength gain of the
concrete over time increased in the presence of POFA.
d. OPSC specimens subjected to continuous water curing had
higher compressive strength compared to those subjected to
partial water curing and air curing conditions. The incorporation
of POFA could reduce the sensitivity of OPSC towards poor
curing.
e. The optimum POFA replacement level for the compressive
strength enhancement of OPSC is between 10 and 15% while
significant reduction in compressive strength was observed
when POFA content was increased to 20% and 25%.
f. Increase in POFA content up to 25% led to reduction in the
splitting and flexural tensile strengths of OPSC while no significant
influence of POFA was noticed in terms of the MOE of
concrete.
g. The mix with 10% POFA exhibited the most optimum sustainability
performance considering both cost and eco-efficiency of
OPSC.