Performance of an organic corrosion inhibitor in concrete affected by both chloride and carbonation-induced corrosion

摘要

Many different approaches to concrete repair and protection exist, with varying degrees of cost and reliability. The use of corrosion inhibitors has been promoted widely as a pragmatic means of concrete repair and protection. Like all repair techniques however, the use of corrosion inhibitors in concrete has limitations that need to be understood prior to use. In this study the performance of an organic corrosion inhibitor in reducing the rate of corrosion and delaying the onset of corrosion in reinforced concrete exposed to both chloride and carbonation environments was investigated. Laboratory trials were undertaken on specimens treated with the corrosion inhibitor before and after accelerated chloride and carbon dioxide ingress. Corrosion rate, rebar potential and resistivity were measured. Results indicate that organic corrosion inhibitors are capable of reducing corrosion rates and delaying the onset of corrosion and therefore can potentially extend the service life of reinforced concrete structures. Both admixed and penetrating forms of the corrosion inhibitor do however have defined limits of performance and should not be used indiscriminately. The effectiveness of the inhibitor was also assessed on site structures exhibiting severe corrosion. Findings from site studies confirmed that surface application of the corrosion inhibitor reduced the corrosion rate of reinforcement embedded in contaminated concrete when compared with untreated elements.