Argument for Using Coarse Cements in High-Performance Concretes.
Argument for Using Coarse Cements in High-Performance
Bentz, D. P.; Haecker, C. J.
Cement and Concrete Research, Vol. 29, 615-618, 1999.
concretes; hydration; particle size distribution
The NIST cement hydration microstructural model and
experimental studies are used to investigate the effects
of particle size distribution and water-to-cement ratio
on hydration kinetics. Cement hydration is limited by
the availability of water at the cement particle
surfaces. Because a reaction layer forms around each
cement particle during hydration, this availability is
controlled by two factors: the overall water-to-cement
ratio and the particle size distribution of the cement.
As the water-to-cement ratio is decreased, the effects
of particle size distribution on ultimate degree of
hydration become less significant. Thus, in the new
generation, high-performance concretes, more coarsely
ground cements may provide good performance, resulting
in substantial energy savings due to a reduction in
grinding time. This implies that cement fineness should
be optimized based on the mixture proportions of the
concrete in which it will be used.