Corrosion-resistant rebar extends service life of concrete bridge structures

摘要

A common cause of reinforced concrete bridge deterioration is corrosion of the reinforcing steel bars due to exposure to chloride ions from deicing salts and marine environments that permeate the concrete. In the absence of chloride ions, concrete's higher pH promotes the passivation of the reinforcing steel, where a passive oxide film is formed on the steel's surface that protects the metal from corroding. When chloride ions, in combination with moisture and oxygen, penetrate the concrete and interact with the reinforcing steel, its protective passive film is compromised and the steel is susceptible to corrosion.