A Comparative Study Between the Early Stages Hydration of a High Strength and Sulphate Resistant Portland Cement and the Type II F Portland Cement Through Non Conventional Differential Thermal Analysis and Thermogravimetry

This work presents a study, which compares the early stages of hydration of a High Initial Strength and Sulphate Resistant Portland Cement (HIS SR PC) with those of Type II F Portland Cement (PC II), by Non-Conventional Differential Thermal Analysis (NCDTA) within the first 24 hours of hydration. Water/cement (w/c) ratios equal to 0.5, 0.6 and 0.66 were used to prepare the pastes. The hydration of these two types of cement was monitored on real time by NCDTA curves, through the thermal effects of the hydration reactions, from which cumulative evolved energy curves were obtained. These techniques allow one to analyse the influence of each type of cement on the main stages that occur during the hydration process. Thermogravimetric analysis were also performed at 4 and 24h of hydration for both cements, to analyse the influence of each kind of cement on the amount of the main formed hydrated products. The results showed that with 4h of hydration, the total combined water amount released from the hydrated products was higher for the PC II pastes than for the HIS SR PC pastes. Otherwise, with 24h of hydration, the amount of the total combined water released from the hydrated products was higher for the HIS SR PC pastes than for the PC II pastes.