Influence of Curing Conditions on Water Loss and Hydration in Cement Pastes With and Without Fly Ash Substitution.
Influence of Curing Conditions on Water Loss and
Hydration in Cement Pastes With and Without Fly Ash
Bentz, D. P.
NISTIR 6886; 20 p. July 2002.
Available from:: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
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cements; cement paste; water loss; hydration; fly ash;
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 ASTM Type I and blended portland cement
pastes with a water-cementitious materials ratio (w/cm)
of 0.40. 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
(exposed 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 Type I portland cement