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Influence of Curing Conditions on Water Loss and Hydration in Cement Pastes With and Without Fly Ash Substitution



Dale P. Bentz


The proper curing of concrete is paramount to achieving desired strength and durability performance in the field. Because blending components often react at different rates from portland cement, blended cements may require that special attention be paid to prolonged curing. This report summarizes an exploratory study on the influence of curing conditions on water loss and hydration in ordinary and blended portland cements. The blended cement contains about 20 % by mass fly ash substitution for cement. Water loss/gain under various curing conditions is monitored both globally by bulk mass (loss) measurements and locally using the NIST X-ray absorption apparatus. Hydration is assessed based on the measurement of non-evaporable water content after 31 d of curing. Curing conditions include no curing (open to the environment throughout the curing period), sealed curing, and saturated curing for 1 d, 3 d, and 6 d. The cement paste with the fly ash substitution is observed to be more sensitive to curing conditions than the conventional ordinary portland cement paste.
NIST Interagency/Internal Report (NISTIR) - 6886
Report Number


building technology, cement paste, curing, evaporation, fly ash, hydration


Bentz, D. (2002), Influence of Curing Conditions on Water Loss and Hydration in Cement Pastes With and Without Fly Ash Substitution, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 19, 2024)


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Created July 1, 2002, Updated February 19, 2017