Corrosion Behavior of Steel Reinforcement in Chloride Admixed Self-Compacting Concrete Subjected to Different Exposure Conditions

Abstract

Abstract Chloride-induced corrosion is one of the most significant durability problems faced by reinforced concrete structures. In this study, chloride-induced corrosion performance of steel reinforcement was evaluated in self-compacting concrete (SCC) in the presence of internal chloride. Two types of exposure condition were adopted, i.e., air curing (laboratory drying) and water curing with alternate wetting-drying cycles, till an exposure duration of 450 days. After 450 days, only water curing specimens were further exposed to 5 % sodium chloride (NaCl) solution with alternate wetting-drying cycles for another 240 days. The corrosion behavior of steel reinforcement was monitored through half-cell potential and linear polarization resistance measurements. The obtained results indicated that there is no systematic variation in corrosion potential between two exposure conditions. SCC specimens exposed to normal water curing with alternate wetting-drying cycles showed lower corrosion current density than those exposed to air curing. Ordinary portland cement (OPC)–based SCC showed better corrosion performance than portland pozzolana cement and OPC + 20 % fly ash–based SCC during an early exposure period in the presence of internal chloride; however, the opposite variation was observed during later ages after exposure to 5 % NaCl solution.