TITLE:
Packing Density Improvement through Addition of Limestone Fines, Superfine Cement and Condensed Silica Fume
AUTHORS:
J. J. Chen, A. K. H. Kwan, P. L. Ng, L. G. Li
KEYWORDS:
Condensed Silica Fume, Limestone Fines, Packing Density, Superfine Cement, Voids Ratio
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.4 No.7,
July
25,
2016
ABSTRACT: Adoption of a low
water/powder (W/P) ratio is the key to improve the strength and durability of
concrete, which relies on a high packing density because fresh concrete requires
excess water to offer flowability. To obtain a high packing density, powders
with different particle sizes, including limestone fines (LSF), superfine
cement (SFC), condensed silica fume (CSF), were added to the cement paste and
the resulting packing densities were measured directly by a newly-developed wet
packing test. Results demonstrated that addition of powders with a finer size
would more significantly improve the packing density but the powders should be
at least as fine as 1/4 of the OPC to effectively improve the packing density.
Packing density and voids ratio relationship showed that a small increase in
packing density can significantly decrease the voids ratio, which could allow
the W/P ratio to be reduced to improve the strength and durability of the
concrete without compromising the flowability.