Quantitative estimation on delaying of onset of corrosion of rebar in surface treated concrete using sealers

Abstract

Surface treatment on the concrete surface using sealers reduces the rate of permeability of chloride and moisture through the concrete. The delaying of onset of corrosion is evaluated for surface treated and untreated concrete using electrochemical techniques. After conducting rapid chloride permeability test (RCPT), using Nernst–Plank equation, the diffusion coefficient of chloride (Deff) is calculated. Substituting threshold chloride concentration of rebar (Cth) from cyclic polarization test in the ficks second law, the time to initiation of corrosion (Ti) is arrived. From the results it is found that the treated concrete with alkyltrialkoxy silane sealer delays the onset of corrosion by four times than that of untreated concrete.

Keywords

• Reinforced concrete
• Cyclic polarization technique
• Impressed voltage test
• Time to initiation
• Surface treated concrete