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Estimating the 95th Percentile of the Paste-Void Spacing Distribution in Hardened Cement Paste Containing Air Entrainment.

Estimating the 95th Percentile of the Paste-Void Spacing
Distribution in Hardened Cement Paste Containing Air
Entrainment.
(813 K)

Snyder, K. A.

RILEM Workshop on Frost Dmage in Concrete (PRO 25).
Proceedings. June 28-30, 1999, Minneapolis, MN, 75-85
pp, 1999.

### Keywords:

cements; air entrainment; cement paste; air-void
spacing; air-void system; freeze-thaw; spacing equations

### Abstract:

*
The spacing equations of Powers, Philleo, and Pleau and
Pigeon are used to estimate the uniform thickness of
paste surrounding entrained air voids that is required
to encompass 95% of the air-paste system. Spacing
equation accuracy is determined by comparison to the
numerically exact result of Lu and Torquato. The air
void system is approximated by spheres with radii from a
lognormal distribution. For the systems studied here,
both the Philleo and the Pleau and Pigeon equations are
accurate to within approximately 10%. The Powers spacing
factor can be used to estimate the same quantity to
within a factor of two, and could be made far more
accurate by adjusting the result using the variance in
the air void radius distribution.
*