Discussion of "The Use of the Flow Length Concept to Assess the Efficiency of Air Entrainment With Regards to Frost Durability: Part 1. Description of the Test Method" by R. Pleau and M. Pigeon.
Discussion of "The Use of the Flow Length Concept to
Assess the Efficiency of Air Entrainment With Regards to
Frost Durability: Part 1. Description of the Test
Method" by R. Pleau and M. Pigeon.
(381 K)
Snyder, K. A.
Cement, Concrete, and Aggregates, Vol. 19, No. 2,
116-119, December 1997.
Keywords:
air entrainment; frost durability; flow length concept;
building technology; concretes; air-void system;
air-void spacing
Abstract:
In an approach similar to that of Philleo, the authors
have attempted to calculate the distribution of
distances between random points in the paste and the
nearest air void surface (paste-void proximity
distribution). This approach has a distinct advantage
over single parameter spacing equations that cannot
characterize a distribution of spacings. However, like
the Philleo equation, the authors' equation for the
paste-void proximity distribution is an approximation,
and is only exact for zero air content. This dicussion
will demonstrate this point calculsively for
monodispersed spheres. Additionally, by comparing
results of a similar numerical experiment published
previously to predictions based upon the
authors'equation, it can be demonstrated that the
authros' equation contains considerable error at
concrete air content of 5% for a zeroth-order
logarithmic distribution of sphere diameters.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899