Chlorine diffusion resistivity of sustainable green concrete in harsh marine environments

Abstract

Cement used in concrete is one of those materials which the production process is releasing considerable amount of CO2. Most researches are focusing on replacing cement with any natural and/or recyclable components. On the other hand, durability should be taken into account in case of any changes in concrete components especially in reinforced concrete infrastructures in aggressive environments since chloride-induced corrosion is currently one of the main issues in marine reinforced concrete structures. Zeolite, a type of natural supplementary cementitious material, can be used as replacement of cement in order to make sustainable eco-friendly concrete. In this research, an experimental study was conducted to evaluate the durability of concrete specimens incorporating natural zeolite (0–30% cement replacement), metakaolin (0–15% cement replacement) and silica fume (0–10% cement replacement) in terms of chloride diffusion exposed to tidal and splash exposures in a harsh marine environment, along with a parallel study under laboratory conditions. Results of this study indicated that the optimum replacement level for zeolite in concrete obtained in a range between 10% and 20% resulted in 60%–70% improvement in chloride penetration resistance in terms of concrete durability in aggressive environments.