This paper deals with air-permeability of concrete cover and its relation to carbonation resistance of concretes. A comparative study was performed with three kinds of air-permeability testers (the single-chamber method, Figg's intrusive method and the Torrent permeability test method (TPT)), and their capabilities to differentiate the qualities of concretes were examined using six different concrete specimens. The test methods were capable of detecting correctly the expected differences of the concrete quality &ldqou;penetrability” at a significant or highly significant level. Classifications for air-permeability of the RILEM CEMBREAU method and the TPT were compared to carbonation depths of concretes and their applicability was discussed. Also, threshold values for air-permeability of the single-chamber method and Figg's intrusive methods were proposed. Future overviews and issues to establish performance-based control of durability of RC structures were described.
