Determining hydraulic properties of concrete and mortar by inverse modelling

This paper presents a methodology and results on estimating hydraulic properties of the concrete and mortar considered for the near surface disposal facility in Dessel, Belgium, currently in development by ONDRAF/NIRAS. In a first part, we estimated the van parameters for the water retention curve for concrete and mortar obtained by calibration (i.e. inverse modelling) of the van Genuchten model [1] to experimental water retention data [2]. Data consisted of the degree of saturation measured at different values of relative humidity. In the second part, water retention data and data from a capillary suction experiment on concrete and mortar cores was used jointly to successfully determine the van Genuchten retention parameters and the Mualem hydraulic conductivity parameters (including saturated hydraulic conductivity) by inverse modelling. WATER RETENTION CURVES OF CONCRETE AND MORTAR Concrete constitutes one of the main materials used in engineered barriers limiting radionuclide leaching to the environment, especially in case of near surface disposal of low-level radioactive waste. It is then crucial to accurately determine the (unsaturated) flow and transpor