Table 4: Main properties of the cement and fly-ash Cement type I Cement type II* Fly-ash SiO2 (%) 19.4 20.3 58.5 Al2O3 (%) 5.5 6.5 23.5 Fe2O3 (%) 3.3 3.2 5.8 CaO (%) 63.1 58.0 2.4 MgO (%) 1.6 1.5 1.8 SO3 (%) 2.7 2.6 0.9 Loss on ignition (%) 2.85 6.13 5.5 Fineness blaine (cm2/g) 3393 3875 4715 Specific gravity (t/m3) 3.12 3.05 2.35 * Cement type II includes 620% limestone filler