THE ELECTRICAL CONDUCTANCE AND HYDRATION KINETICS OF ARTIFICIAL POZZOLANA-CEMENT PASTES

Artificial pozzolana were made by firing of two types of clays at two temperatures (600 and 700 degrees C). Different artificial pozzolana-P ortland cement pastes were made using a water/cement ratio of 0.40 by weight of the cement blend. Each cement paste was examined for hydrati on kinetics at 20 degrees C as well as electrical conductance at 20 an d 35 degrees C. The results of hydration kinetics indicated a sort of phase transformation of hydration products at the intermediate stages of hydration. Electrical conductance studies demonstrated two maxima a t 20 degrees C; only one maximum at 35 degrees C was detected at the e arly stages of hydration. All results could be related to the sequence of the initial hydration reaction and the mode of disruption of the e lectrically insulating coating layers around the grains of the cement constituents.