Possibility of pore size distribution application to the description of air-entrained concrete porosity structure

Air void size and number distribution constitutes a major characteristic, which substantially contributes to building up concrete resistance to cyclic freezing and thawing. The standard pore spacing factor L is based on the Powers model. Due to the assumptions made in the model, it may not be able to represent the real structure of air pores in the concrete. Consequently, it is necessary to look for other methods to describe this structure. The sought model needs to account for variability in sizes of pore chords and pore random spacing in the paste. The paper analyses the distribution type and compares porosity characteristics obtained with measurements, and on the basis of the distribution. The analysis aims to assess if it is possible to substitute chords in the 0 to 400 μm range with their distribution. Another purpose of the analysis is to compare air pore structure parameters obtained by computations on raw data with the results received on the basis of pore size distribution for a given concrete.