Reactive transport through porous media plays a critical role in a wide range of natural and engineered systems in which fluid flow, solute transport, and solid-fluid interactions are tightly coupled. A combination of convective transport and ionic diffusion governs the spatial and temporal evolution of reactive species within the pore network and may strongly influence long-term material behavior. Of particular interest is the transport of ionic species such as chloride or iodide in cementitious materials, which exhibit both mobility in the pore solution and an affinity to interact with the solid matrix. In many porous materials, ions may bind reversibly or irreversibly to the solid phase, which can significantly alter effective transport rates and spatial concentration profiles. Knowledge about the behavior of chloride ions in porous media is especially critical for steel reinforced concrete applications. As chloride causes electrochemical corrosion processes in steel reinforcements, absorption of chloride ions into the concrete matrix may improve the durability of materials. We present a continuum mechanical framework for modeling reactive fluid transport through a saturated porous medium using the concepts of superimposed continua. Particular focus is put on a novel approach to model sorption and desorption processes of ionic species at the internal surfaces of the porous medium. By explicitly accounting for chemical processes at internal surfaces, the framework provides improved insight into the influence of chemical components on hydraulic conductivity. In order to test the robustness of the results, numerical studies are performed. Additionally, computed tomographic scans of saturated concrete samples are collected and used for model calibration and validation.