A probabilistic technique for entrained air void analysis in hardened concrete

•We propose an alternative method to analyze entrained air voids in hardened concrete.•A probabilistic 3D reconstruction is derived from 2D measurements.•A new spacing factor is proposed and compared to the classic Powers spacing factor.•The alternative spacing factor is an improvement over the classic spacing factor.

A novel method that utilizes the lineal-path function to ascertain a probability density function for the three-dimensional size distribution of entrained air voids directly from plane polished sections of hardened concrete is proposed. The results then treat the spacing factor in terms of a probabilistic maximum distance from a random point in the cement paste matrix to the periphery of an air void, where air voids are treated as a polydispersed sphere system. The model was applied to concretes with various air entrainment admixture types and dosages. The results suggest that the model may offer a better assessment of the system for use in assessing durability and studying admixtures, as well as providing a new tool for spatial characterization of heterogeneous and porous materials.