Replacement of "Coarse" Cement Particles by Inert Fillers in Low w/c Ratio Concretes. Part 2. Experimental Validation. Communication.
Replacement of "Coarse" Cement Particles by Inert
Fillers in Low w/c Ratio Concretes. Part 2.
Experimental Validation. Communication.
Bentz, D. P.
Cement and Concrete Research, Vol. 35, No. 1, 185-188,
cements; blended cements; compressive strength;
hydration; particle size distribution
It has been suggested that in low water-to-cement ratio
(w/c) concretes, the "coarser" cement particles could be
replaced by an "inert" filler with little loss in
performance in terms of hydration and strength
development. This communication presents the results of
an experimental study conducted to validate this
hypothesis, using a coarse limestone filler and a
classified cement. The cement and limestone powders were
both classified with a cutoff diameter of about 30 mum.
The coarse limestone was then blended with the fine
cement, and water-to-solids ratio=0.3 pastes and mortars
were prepared to compare to reference (original cement
powder) systems. The results for chemical shrinkage for
the pastes were consistent with a simple dilution of the
cement by the limestone and also with the results
predicted by the CEMHYD3D hydration model. In mortars,
the predicted compressive strength loss in the filled
system at 7 days was consistent with model predictions,
and furthermore, at 56 days, no detectable difference in
strength was measured. Thus, this study further supports
the idea that coarse limestones could be used to replace
equivalent size cement particles in low w/c concretes
with little loss in hydration and strength performance.