Using polymers to minimize corrosion of steel in concrete

Efforts to restrict chloride transport can lead to changes in the corrosion rate of steel in cement-based materials, such as concrete. Two potential methods have been examined for several years. They include: the addition of polymer fibers to the concrete at the time of mixing; and the encapsulation of previously contaminated concrete using polymer resin or polymer composites. It has been reported that the first method could minimize initial chloride intrusion and that the latter method could prevent additional chloride intrusion if concrete is already salt-contaminated. The effectiveness of these methods in minimizing corrosion was evaluated based on changes in corrosion rates determined using polarization resistance measurements. The results, which have been observed over a period of several years, will be reported. Limitations of polarization resistance measurements to evaluate the effectiveness of these methods as means of minimizing corrosion will also be discussed.