Model Investigation of the Influence of Particle Shape on Portland Cement Hydration.
Model Investigation of the Influence of Particle Shape
on Portland Cement Hydration.
Bullard, J. W.; Garboczi, E. J.
Cement and Concrete Research, Vol. 36, No. 6,
1007-1015, June 2006.
cements; hydration; particle shape; kinetics;
The NIST Virtual Cement and Concrete Testing Laboratory
(VCCTL) is used to simulate the influence of particle
shape on the hydration kinetics and setting of portland
cement. Building on previous work in reconstructing
particle shapes from real cements, real-shape particles
are used to produce three-dimensional digitized cement
paste microstructures, and the hydration of these
microstructures is tracked using VCCTL. The degree of
hydration and percolation of solids is monitored and
compared to experimental data at several water.cement
ratios. The simulations predict that shapes of particles
influence cement hydration in two ways: the additional
surface / volume ratio relative to spherical particles
results in greater rates of hydration, and the
anisometry in shape influences the degree of hydration
at which the particles and hydration products percolate
to form a stiff three-dimensional network.