Using particle packing models (PPMs) in combination with limestone fillers has been shown to be effective in proportioning eco-efficient concrete mixtures with reduced Portland cement content, resulting in suitable performance in fresh and short-term hardened states. However, the decrease in Portland cement and increase in limestone fillers may lower the pH of concrete, raising concerns about durability and long-term performance, potentially leading to increased corrosion of steel reinforcement in the presence of carbonation or chlorides. In this study, the performance of three eco-efficient concrete mixtures with varying cement (250, 200, and 150 kg/m³) and inert filler contents is evaluated against accelerated chloride exposure. The findings highlight the influence of the mixture proportioning and water-to-cement ratio on the resistance to chloride ingress. Ultimately, it is verified that the distance between cement particles is a major contribution towards chloride ingress.