Performance characteristics of surface coatings applied to concrete for control of reinforcement corrosion

• Published in: Construction & building materials 2000-02, Vol.14 (1), p.55-59
• Main Authors: Seneviratne, A.M.G, Sergi, G, Page, C.L
• Format: Article
• Language: English
• Subjects: Carbonation; Reinforcement corrosion; Surface coatings
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/S0950-0618(00)00011-8

Three elastomeric surface coatings were applied to naturally carbonated concrete components obtained from buildings that were suffering from reinforcement corrosion. Monitoring of the internal relative humidity of the concrete revealed that all three coating systems were able to exclude water from the carbonated components for a period of 2 years but only one of them was able to sustain its performance for a period of up to 5 years in an urban UK outdoor environment. Dynamic mechanical thermal analysis suggested that the most successful coating was able to maintain its elastomeric properties over the required period of exposure and over a wide range of operational temperatures. It also had a relatively low but uniform bond strength to the concrete and this appeared to have a beneficial effect on its ability to accommodate movements of the substrate. Such coatings are considered capable of extending the service-lifetimes of carbonated reinforced concrete structures in cases where significant chloride contamination does not exist and where the only substantive route for moisture ingress is via the coating.