Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solution
are widely recommended alkali activators. NaOH in a pellet
form with a specific gravity and purity of 2.13 g/cm3 and 99%,
respectively was used. The Na2SiO3 in liquid form with a density
of about 1.5 g/ml at 20 C, a modulus ratio of 2.5 (SiO2/Na2O,
SiO2 = 30% and Na2O = 12%) and specific gravity of 1.5 was used
along with NaOH as alkali activator.