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Author
Snyder, K. A.
Title
Estimating the 95th Percentile of the Paste-Void Spacing Distribution in Hardened Cement Paste Containing Air Entrainment.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD
Book or Conf
RILEM Workshop on Frost Dmage in Concrete (PRO 25). Proceedings. June 28-30, 1999, Minneapolis, MN, 75-85 p., 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.