Title: Comparison of TDR and X-ray method for determining moisture transport parameters
Abstract: This work compares two methods, the X-ray method and the time domain reflectometry (TDR) method, which are used for determining moisture transport parameters, such as moisture diffusivity, w-λ profile and absorption coefficient. Both methods are suitable for measuring instantaneous moisture content profiles during water transfer through a porous material. However, while the X-ray method is fully non-destructive, the TDR measurement requires installation of TDR probes into the measured material and the obtained results can be influenced by the quality of the contact between the TDR probe and material. The moisture transport parameters were determined from the measured moisture profiles during the process of water uptake, realized on calcium silicate samples. The same measurement arrangement and sample treatment were applied for both methods. The moisture diffusivity moisture dependence was calculated using Boltzmann transformation. The moisture transport parameters obtained by the TDR method were sufficiently close to the values obtained from the X-ray measurement.