The rate of deterioration of concrete structures is normally affected by the rate at which harmful substances can penetrate into the concrete. Aggressive substances can move into concrete by different transport mechanisms. The main transport mechanisms that could promote the deterioration of concrete structures are diffusion, permeation, capillary absorption and migration. The rate of chloride penetration into concrete has been found to depend on many factors including the porosity and permeability of concrete. Accordingly, concrete porosity is one of the most important parameters that influences the durability of concrete. Furthermore, when the concrete structures are subjected to aggressive environments such as marine environments the primary transport mechanism of chloride ion ingress is often diffusion. For that reason, the chloride diffusivity and porosity are very important durability parameters since they may play a major role in accelerating deterioration and thus reducing the service life of structure. Intensive experimental works were carried out where cement pastes specimens and concrete mixes were prepared at different w/c ratios mixed with 0, 2 and 3 % Electric Arc Furnace Dust addition. The results are very promising and revealed that addition of Electric Arc Furnace Dust (EAFD) reduced the coarse capillary porosity effectively and improved resistance to chloride ingress into concrete, hence this will improve corrosion resistance of reinforced concrete structures located in aggressive marine environment. More details in the results can be found in this paper.