Robert Phillip Darbe

Modeling the Effect of Curing Temperature and Pressure on Cement Hydration Kinetics

This study shows that chemical shrinkage tests can be used to evaluate the hydration kinetics of cement cured under different temperatures and pressures. Test results suggest that the effect of curing condition on cement hydration is represented by a scale factor on hydration rate as a function of degree of hydration. Therefore, the hydration kinetic curves of cement at any curing condition can be predicted from those of a reference condition by simple coordinate transformations (that is, scaling the x- and/or y-axis using the scale factor). The dependence of the scale factor on curing temperature and curing pressure is related to the activation energy and the activation volume of the cement, respectively. Test results of five different types of oil well cements in this study give an apparent activation energy ranging from 42.5 to 52.6 kJ/mol and an apparent activation volume ranging from –22.3 to –29.5 cm3/mol.