APPLICATION OF DEFF-MR CURVE ANALYSIS TO EXTERNAL DRYING DATA FOR IDENTIFYING THE MOISTURE TRANSPORT MECHANISMS

The Deff–MR (effective diffusivity vs. moisture ratio) curve approach, developed by the authors, has been successfully used over the past 15 years to optimize drying regimes for clay-based materials. While its practical value in industrial and laboratory settings is well-established, its theoretical contribution to identifying internal moisture transport mechanisms remains underutilized in broader drying applications. To assess its universal relevance, this study applies Deff–MR curve analysis to digitized drying and shrinkage data from multiple external sources. The data were extracted from literature graphs and reanalysed using the proposed Deff–MR framework. Despite differences in experimental procedures and diffusivity calculation methods, the analysis revealed consistent transition points corresponding to known moisture transport mechanisms, including capillary flow, vapor diffusion, and Knudsen diffusion. These findings support the broader applicability of the Deff–MR method as a diagnostic tool for identifying dominant internal moisture movement mechanisms across different drying scenarios and materials.