Chemical compositions of Portland cement type I, original fly ash, coarse fly ash, FAG, and condensed silica
fumes are given in Table 3. According to the chemical composition, the original fly ash, coarse fly ash, and FAG
are the fly ash of Class F as prescribed by ASTM C 618 since the sum of the components SiO2, Al2
O3, and Fe2O3 are higher than 70%, and the loss on ignition (LOI) and SO3 is not higher than 6% and 5%, respectively. It was found that the grinding process did not have much effect on the chemical composition of fly ash. LOI for FAG (2.09%) was higher than LOI for original fly ash (0.23%) and coarse fly ash (0.08%) since the very high fine fineness of FAG by grinding process can cause easy in burning and the result conformed to the previous research [9]. The SFI and SFII consist of high-SiO2 content at 93.80% and 94.09%, with LOI of 4.89% and 4.65%, respectively. Their chemical
compositions conformed to ASTM C 1240 since the component of SiO2 is higher than 85% and the LOI is less than 6%.