Electrochemical performance of a localized repair. Effect of applying a primer and a bonding membrane

Abstract

It is customary, in the constructions at the North of Yucatán, to employ primers to the rebars as a repair method in reinforced concrete, it has been observed in the literature that using primers alone presents an electrochemical behaviour still under discussion. Under these circumstances, several investigations have focused on the evaluation of the factor against or in favour of using primers as a repair method in a tropical marine environment. In this paper, the effects of applying a bonding membrane and the galvanic effect generated by the repair are also discussed. Small reinforced concrete columns were prepared and exposed under accelerated degradation cycles. After the activation of the rebars, the columns were repaired applying three types of primers, leaving one bar as control. After curing, the columns were exposed again to the same environment and their electrochemical behaviour was monitored. Corrosion potentials, polarization resistance, carbonation and chloride content were measured as a function of time. Conclusions suggest that the bonding membrane reduces the corrosion rates for the conditions and exposure time studied. The galvanic effect was observed after repairing the columns with and without bonding membrane, but with a tendency to reduce with time. The primers applied helped to reduce the galvanic effect of the repair, and to increase the polarization resistance.