Methodology Comparison for Concrete Adiabatic Temperature Rise

摘要

Concrete adiabatic temperature rise is often used to predict temperature development in mass concrete thermal control plans. Several experimental methods are currently being used to obtain the adiabatic temperature rise. This study compared the adiabatic temperature rise from seven concrete mixtures obtained from fully adiabatic, semi-adiabatic, and isothermal calorimetry. The study found a low adiabatic temperature rise difference between semi-adiabatic calorimetry and filly adiabatic calorimetry for ordinary portland cement concrete mixtures for 28 days and for mixtures containing Class F fly ash during the first 10 days after mixing. Semi-adiabatic calorimetry did not match well to fully adiabatic calorimetry results when slag cement was used because the rate of heat development could not be well described by a three parameter heat of hydration model. Adiabatic temperature rises calculated using isothermal calorimetry results did not compare favorably to measured fully adiabatic results, even when temperature effects on hydration rate were accounted for using an Arrhenius apparent activation energy approach.