Utilization of Palm Oil Fuel Ash in High-Strength Concrete

This paper presents use of improved palm oil fuel ash (POFA) as a pozzolanic material in producing high-strength concrete. The POFA was ground by ball mill until the median particle size was reduced to about $10\mu m$. It was used to replace portland cement, ASTM Type I, by 10, 20, and 30% by weight of cementitious materials to make high-strength concrete. It was found that high-strength concrete can be achieved by using ground POFA to replace portland cement Type I up to 30%. At the age of $28\mathrm{days}$, concretes containing 10, 20, and 30% of ground POFA gave compressive strengths of 81.3, 85.9, and $79.8\mathrm{MPa}$, respectively. Concrete with 20% replacement of ground POFA had the highest strength. It is slightly higher than that of concrete containing 5% condensed silica fume and about 92–94% that of 10% condensed silica fume concrete. The ground POFA content up to 30% had slightly effect on lowering the modulus of elasticity of concrete. In addition, the use of ground POFA reduced the peak temperature rise of concrete under semiadiabatic conditions.