Quality assurance and quality control of air entrained concrete

Abstract It is generally recognized that the air void structure of concrete is a critical parameter for the durability of concrete subjected to frost/thaw action and deicing salts. In the first part of this article an overview is given of the different methods characterizing the air void structure in fresh and hardened concrete. The calculation of the parameters from a traditional air void analysis following ASTM C 457 is compared with more advanced calculation methods on results obtained from point, chord, diameter and area measurements. A new parameter is formulated which characterizes the spacing between the air bubbles more precisely.