Effect of polymer modified cementitious coatings on chloride-induced corrosion of steel in concrete

The paper deals with the study of the effect of polymer modified cementitious mortars on chloride-induced corrosion of steel reinforcement in concrete. Nowadays, many results obtained by standard and short-term tests are available in the literature. The paper reports more than 15 years exposure testing on two commercial coatings, with different polymer/cement ratio. The effect of coatings on corrosion initiation and propagation has been studied by the monitoring of corrosion potential and corrosion rate of rebars in concrete subjected to chloride ponding; chloride profiles, coating adhesion, water content, and corrosion morphology have been also analyzed. It was demonstrated that polymer modified cementitious mortars can delay corrosion initiation caused by chloride penetration into concrete. Owing to high resistivity of coated concrete, corrosion rate is reduced. The protective effect is more pronounced as the polymer content increases from 0.35 to 0.55. The results have been elaborated to estimate the possible increase of service life gained with this additional protection method, compared with other solutions.