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 mum. It was used to replace portland cement, ASTM Type 1, 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 days, concretes containing 10, 20, and 30% of ground POFA gave compressive strengths of 81.3, 85.9, and 79.8 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.