Abstract
During characterization efforts of complex sites and geologies, it is important to estimate material properties efficiently and robustly. We present data and modeling related to the heat of wetting process during spontaneous imbibition, as observed in zeolitic tuff. The heat of wetting is due to adsorption of liquid water and water vapor to an oven-dry core sample and results in an observable temperature rise. The fitting of numerical models to imbibition observations allows simultaneous constraint of single-phase (porosity, permeability), two-phase (van Genuchten m and alpha), thermal (thermal diffusivity), and transport (tortuosity) properties from a single imbibition test. Petrographic analysis informs how microstructure connectivity and pore-lining phases affect the imbibition process. Estimating multiple properties simultaneously from a single test on a core sample helps ensure consistency in interpreted material properties. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525 (SAND2023-07021A).