Laval University, Sainte-Foy, Québec
School of Architecture, Laval University, Sainte-Foy, Québec
This paper describes a numerical method to determine the flow length and other characteristics of the air-void system in hardened concrete. Physically, the flow length represents the distance that freezable water must travel through the cement paste to reach the perimeter of the nearest air void. It is expected to be a better indicator of the frost durability of concrete than the commonly used Recommended Practice for the Microscopial Determination of Air Void Content and Parameters of the Air Void System in Hardened Concrete (ASTM C 457) spacing factor. The flow length is obtained from the microscopical examination of polished concrete sections. It can be determined by recording the size-distribution of the circles intercepted by the plane on a given surface area or by recording the size-distribution of the chords intercepted along a given line of traverse. A numerical example is given to illustrate the advantages of the proposed method. The flow length is very similar to the Philleo factor, but it provides a more accurate estimation of the real distribution of air voids through the cement paste.
Paper ID: CCA10308J