Relationship between air diffusivity and permeability coefficients of cementitious materials

In this study, the relationship between air diffusivity and permeability in cementitious materials was investigated to theoretically investigate the relationship between diffusion and air permeability coefficients. First, an equation to correlate air diffusivity and permeability in a straight circular tube was derived. Then, existing studies that measured both air diffusivity and permeability and compared reported data were collected and the applicability of the derived equation to cementitious materials was verified. Although a correction factor was not used, the two sets of data showed good agreement quantitatively. This indicates that the derived equation can be applied to cementitious materials including concrete, and measured air diffusivity can be converted to permeability of concrete and vice versa using the derived equation.