[Retracted] Performance of High Strength Concrete Containing Palm Oil Fuel Ash and Metakaolin as Cement Replacement Material

Table 2

Chemical composition of materials.

	Chemical composition (%)
	OPC	POFA	MK
Silicon dioxide (SiO2)	20.63	60.78	55.04
Aluminum oxide (Al2O3)	4.71	6.96	37.44
Iron oxide (Fe2O3)	3.52	5.69	0.75
Calcium oxide (CaO)	60.98	5.20	0.02
Magnesium oxide (MgO)	0.98	4.17	0.81
Sodium oxide (Na2O)	0.06	0.10	—
Potassium oxide (K2O)	1.09	5.40	2.31
Sulfur trioxide (SO3)	4.97	0.22	—
Loss of ignition (LOI)	2.38	3.00	2.50
SiO2+Al2O3+Fe2O3	28.86	73.43	93.23