Electrical-resistivity-based methods for predicting chloride content in concrete have gained popularity due to their simplicity and minimal equipment requirements. However, adapting these laboratory-based standards to field conditions requires including appropriate parameters catering for site-specific factors. Furthermore, considering the push towards net-zero construction, there is a pressing need to extend these methods from Ordinary Portland Cement (OPC) and a limited range of Supplementary Cementitious Materials (SCMs) such as Fly-Ash and Slag to alternative low-carbon cement types such as Limestone Calcined Clay Cement (LC3) and Alkali Activated Cement (AAC). This paper first proposes a systems approach based on physical boundaries to classify influencing parameters into two systems: ‘Concrete’ and ‘Outside-Concrete’. Building on this classification, experimental investigations were conducted to examine the combined effects of these parameters for various cement types and their influence on concrete resistivity. Specifically, this study explored the relationship between permeability and cement composition (both within the ‘Concrete’ system) across five distinct mortar systems—OPC, FA, Slag, LC3, and AAC—and their impact on the chloride diffusion coefficient (Drcm), Gas Permeability Test, and Surface Electrical Resistivity (SER)Test. While Drcm demonstrated an inverse relationship with SER, no direct correlations emerged for permeability. This study tried to explain these variations through the changes in the materials. However, the said observations suggest that Drcm might not be the true representation of the chloride transport, further opening the scope to understand the intrinsic parameters for chloride transport and the methodology of predicting it using resistivity-based methods.