Corrosion Performance of Multiple As-Delivered Steel Reinforcing Bar Types Using the ASTM A955 Rapid Macrocell Test

Chloride-induced corrosion of steel reinforcement is a major durability concern for reinforced concrete infrastructure exposed to deicing salts and other chloride-bearing environments. The use of corrosion-resistant reinforcing bars provides a potential means of extending structural service life; however, comparative information on the performance of different reinforcement systems under identical exposure conditions remains important for material selection. In this study, bare, quenched and tempered, Duplex 2304 stainless steel, epoxy-coated, galvanized, and ChromX-9100 reinforcing bars were evaluated in the as-received condition using the Rapid Macrocell test described in ASTM A955. Corrosion rate, cumulative corrosion loss, and anode corrosion potential were monitored during the 15-week testing period. The Duplex 2304 stainless steel reinforcing bars exhibited the highest resistance to chloride-induced corrosion, with an overall average corrosion loss of approximately 0.25% of that of the bare reinforcing bars. The epoxy-coated, galvanized, and ChromX-9100 reinforcing bars exhibited overall average corrosion losses of approximately 25%, 33%, and 40% of that of the bare bars, respectively. In contrast, the quenched and tempered reinforcing bars exhibited an overall average corrosion loss approximately 25% greater than that of the bare reinforcement. These findings provide a direct comparative assessment of commonly available reinforcement systems and can assist in evaluating reinforcement options for concrete structures exposed to aggressive chloride environments.