Protected‐Paste Volume of Air‐Entrained Cement Paste. Part 1

Abstract

Expressions for the protected‐paste volume of air‐entrained cement paste are derived using the hydraulic‐pressure mechanism of frost damage. The protected‐paste volume is the total common volume of cement paste protected from frost damage by all the air voids in the paste. The derived expressions are shown to reduce to known results for simple geometrical arrangements of air voids. The relative importance of air‐void parameters, material properties, and environmental parameters are deduced from the structure of the derived expressions. It is shown that material and environmental factors have at least as great an effect as air‐void parameters on the protected‐paste ratio. Though the expressions have been derived on the basis of the hydraulic‐pressure mechanism, it is suggested that the concept of protected‐paste volume as well as the form of the expressions may be applicable to other mechanisms of frost damage.