hydration of C3A systems in sodium chloride solutions

ABSTRACT

This study attempts to generate information about the chemistry of the hydration reaction of tricalcium aluminate [C3A] in 0.1 M sodium chloride solutions for hydration times up to one week at room temperature. The effect of gypsum, lime and alite on the progress of the reaction was investigated and the behavior of the dissolved ions was related to that of the solid phases. It is found that the hydration of C3A in 0.1 M sodium chloride solutions, also in the presence of gypsum, lime and alite has shown quite modification compared to that in water. The calcium chloro aluminate hydrate is a major phase formed in the different systems. It appears as a sole hydration product during the hydration of C3A alone in sodium chloride solutions, shows up together with ettringite phase in the presence of gypsum and predominates the ettringite phase in the presence of lime and alire. The hydration rate and the consumption of C3A in sodium chloride solution occur faster in the presence of gypsum than that in the presence of lime and alite