Incorporation of Fly Ash Into a 3-D Cement Hydration Microstructure Model.
Incorporation of Fly Ash Into a 3-D Cement Hydration
Microstructure Model.
(3670 K)
Bentz, D. P.; Remond, S.
NISTIR 6050; 54 p. August 1997.
Available from:
National Technical Information Service
Order number: PB97-206007
Keywords:
cements; computer models; fly ash; simulation
Abstract:
Extensions have been made to the NIST 3-D cement
hydration and microstructure development model to
incorporate pozzolanic materials such as silica fume and
fly ash. These additions will enable the simulation of
the hydration and microstructure development of blended
cements as well as conventional Portland cements. SEM
and image analysis techniques originally developed for
differentiating the cement clinker phases present in a
2-D image of cement particles have been modified and
applied to equivalent images of fly ash particles.
Reactions have been proposed and the appropriate volume
stoichiometries determined for the various components of
fly ash. Some preliminary calibrations of reaction rate
constants and dissolution rates have been performed by
comparison to experimental results for the adiabatic
heat signatures of a variety of concretes with various
water-to-cement ratios and fly ash contents. Further
research needed to complete this calibration is
outlined.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899