Hydration of tetracalcium aluminoferrite in presence of lime and sulfates

The first part of the paper describes conduction calorimetric and SEM studies of the initial first hour hydration of C₄AF and C₃A with water and saturated solutions of lime, gypsum and gypsum with lime. Lime accelerates while gypsum and gypsum with lime strongly retard the hydration of C₄AF. In case of C₃A, the effect is less pronounced. The second part deals with the hydration of C₄AF at later stages in presence of various additives and the same results as above are obtained. Anhydrite has very little influence while the presence of C₃A reduces the effect of gypsum and hemihydrate on hydration of C₄AF. A detailed investigation of the hydration process by means of X-RD, DTA, SEM and calorimetry has also been made.