Degradation process of reinforced concrete under chloride and sulfate attack with and without electric field

Abstract

To explore the feasibility of electric field to accelerate the degradation of large-sized reinforced concrete (RC) members under chloride and sulfate attack, the degradation processes of reinforced concrete under different solutions with and without electric field are studied. The chloride and sulfate contents, steel corrosion, macro and micro morphology of mortar are analyzed. Electric field increases the ion transport and reaction but attenuates the ion interaction. Sulfate does not initiate steel corrosion but delays chloride-induced corrosion under the electric field. The electric field not only accelerates the ingress of sulfate but the leaching of calcium from mortar, the reaction products provide filling effect on the pores macroscopically. The increase of current density decreases the degradation efficiency of electric field. An acceleration factor of electric field on the sulfate attack is newly proposed. It well quantifies the effect of ion species, mixture proportions and exposure regimes on the deterioration acceleration. The outcomings encourage the utilization of electric field to accelerate the chloride and sulfate attack to large-sized RC member in laboratory study.