Application of different testing methods for the air void characterisation in concrete

Concrete is an inherently porous material. Pores in the concrete can be divided into four different groups: gel pores, capillary pores, entrained and entrapped air voids. Characteristics of air voids – size and distribution can be determined in fresh and hardened concrete. In this paper results of testing of six concrete mixtures with increased amount of entrained air voids are presented. Characteristics of air voids total amount, spacing factor and specific surface were determined by pressure method (HRN EN 12350-7), air void analysis in fresh concrete and linear traverse analysis in hardened concrete (HRN EN 480-11). Testing methods are described and results are compared.