corrosion resistance of montmorillonite-modified dense concretes

Corrosion of reinforcing steel bars is the leading cause of deterioration in concrete. in this paper, corrosion process of rebars is controlled using montmorillonite nano-clay particles which are partially substituted as cement in the mix designs. mechanical and physical properties of the mixtures are measured, and steel reinforced concrete specimens are exposed to chloride solution for 6 months. passing electric current through the reinforcement is measured under constant voltage, and potential differences between the steel bars and the concrete surfaces are measured every week. results show that montmorillonite particles remarkably reduce the compressive strength and increase the water absorption, but they can postpone initiating of rebars corrosion and decrease the corrosion rate. negatively charged surface of nano-clay particles repulse oh− and cl− ions and as a result the formation of iron rusts is delayed and the corrosion process is declined. consequently, neither the compressive strength nor the water absorption is suitable as a criterion to accept a reinforced concrete under chloride attacks.