Method for simultaneous determination of the sorption isotherm and the diffusivity of cement-based materials

A method for simultaneous determination of diffusion and sorption properties has been developed. The method is based on measurements of sorption kinetics in a sorption balance. The test specimen is exposed to step changes in the ambient environment and the response is measured as a weight change. The sorption isotherm is evaluated from the final equilibrium mass and given that the weight change is continuously measured and the test specimen has a well-defined geometry, the diffusivity can be calculated from the sorption kinetics. 1