Effect of Statistical Fluctuation, Finite Size Error, and Digital Resolution on the Phase Percolation and Transport Properties of the NIST Cement Hydration Model.
Effect of Statistical Fluctuation, Finite Size Error,
and Digital Resolution on the Phase Percolation and
Transport Properties of the NIST Cement Hydration Model.
Garboczi, E. J.; Bentz, D. P.
Cement and Concrete Research, Vol. 31, No. 10,
1501-1514, October 2001.
cements; cement hydration; cellular automaton;
statistical fluctuation; finite size error; digital
resolution; particle size distribution; cement
The NIST cement hydration model starts with a three
dimensional digital image of cement particles, and then
uses cellular automaton rules to simulate the reaction
of cement with water and the development of cement paste
microstructure. This model is a model of a random
process, using a fairly small periodic unit cell, and
using a digital image with a certain resolution to
represent the reality of continuum shapes. As such, it
is potentially subject to statistical fluctuation,
finite size error, and the effects of digital
resolution. This paper evaluates the model in light of
these potential sources of error, along with the effects
of cement particle size distribution, w/c ratio, and
cement chemistry, by focusing on the phase percolation
and transport property predictions of the model.
Statistical fluctuation and finite size error is shown
to be of minor importance in the model. The effect of
digital resolution is significant, however, but
different from the case of a finite element or finite
difference model. The "best" resolution is not
necessarily the finest resolution, but must be chosen
based on comparison with experiment and various physical
length scales present in cement paste.