Measurement and Prediction of Heat of Hydration of Portland Cement Using Isothermal Conduction Calorimetry

Abstract

AbstractTen industrial Portland cements were carefully tested continuously for up to seven days for their heat of hydration at 23°C, using isothermal conduction calorimetry in accordance with ASTM C1702. The internal mixing procedure was implemented for all the mixes, and external mixing was conducted on one of the cements. The results indicate that for a given Portland cement, the shape of the heat of hydration curve from three days to seven days can be modeled using an exponential function similar to that used in maturity concepts. The findings also indicate that such a function can be used in predicting the seven-day heat of hydration of Portland cement based on data collected for up to 84 h. The suggested approach could eliminate the need for measuring heat of hydration data at ages when the heat flow has decreased substantially to levels at which the signal-to-noise ratio is low. This work effectively proposes a method for accurately predicting the total heat generated by Portland cements at seven days based on heat flow measurements for up to 84 h.