The transport properties, i.e. microstructural behavior and mechanisms related to water and ionic transport within the pore network of cement-based materials can be considered as an indicator for durability and to predict service life of concrete structures. Hence, the investigation of ionic transport is very important to asses ionic diffusion and ionic migration that potentially affect microstructural development of the bulk cement-based matrix. External electric fields are commonly accelerating ion (and water) migration. Numerical works on simulation of these phenomena have been reported, however, most of them consider only a constant ionic diffusion coefficient. This paper deals with the application of the Poisson-Nernst-Planck equations to simulate ionic transport in cement-based systems exposed to external electric potential by considering time dependent diffusion coefficient. The simulation involves solving the equation of mass conservation of individual ionic species coupled with electrostatic potential. Profiles of ionic concentrations and ionic distribution in cement-based systems are presented and discussed.