Performance of fly ash and CNI as corrosion prevention methods for steel reinforcement embedded in cracked HPC concrete exposed to a natural marine environment

Abstract

In this study, the effectiveness of fly ash and a calcium nitrite-based corrosion inhibitor in cracked high-performance concrete was investigated. Concrete prisms were fabricated and the specimens featured artificially transverse cracks 0.25 and 0.5 mm width. These specimens were exposed to a natural marine environment for seven years and the corrosive activity was monitored annually using electrochemical techniques. At the end of the exposure period, chloride ion content at the steel-concrete interface, mass loss, pitting depth and tensile parameters on the steel reinforcement were estimated. It was found that cracking exacerbated corrosion and the prevention methods assessed or their interactions were ineffective. Ultimate strength and ductility losses of the steel reinforcement ranged between 7% and 11% and 44–60% for 0.25 mm crack, while between 11% and 14% and 48–66% for 0.50 mm crack. The results from this research are original because they contribute to elucidating the effect of the interactions between the investigated corrosion prevention methods.