Concrete gas permeability from different methods: Correlation analysis

The paper explores the relation of gas permeability from different methods through both theoretical and experimental investigations. The theoretical basis of different methods is reviewed and the analysis error is derived with respect to their present interpretation methods. The theoretical relations among these methods are further explored. Concrete specimens of 12 mixtures were then prepared and subject to gas permeability measurements, validating the established relation. Further use of gas permeability as durability indicator is elaborated finally. The study shows that (1) theoretical relations exit among the different methods and the key parameter of conversion is the Klinkenberg factor; (2) the gas permeability depends strongly on the binder type, w/b ratio and pore saturation, and the relation between the intrinsic permeability (CemBureau) and Torrent permeability is confirmed; (3) there is urgent need to benchmark the moisture pre-conditioning to make better use of gas permeability as quality indicator.