Differentiation of interlayer and adsorbed water in hydrated portland cement by thermal analysis

Work leading to the new model of hydrated portland cement has shown that much of the water previously considered to reside on free surfaces exists as interlayer water. In the present work samples were conditioned at various relative humidities for times varying from to 14 months and were dried to two different levels before conditioning, one being d-dry. Conditions were chosen, based on the model, so that the different states of water could be clearly illustrated. It was concluded that thermal analysis allows differentiation of interlayer and physically adsorbed water and that the different degrees of drying and very long times allowed for equilibration support all sorption results on which the new model of hydrated portland cement was based.