The Effect of Freeze‐Thaw Damage on Corrosion in Reinforced Concrete

Abstract

The existing studies of the corrosion of reinforced concrete have mainly focused on the interface area and chemical ion erosion, ignoring the specific service environment of the reinforced concrete. In this study, the effect of freeze-thaw damage was investigated via corrosion experiments under different freeze-thaw cycle conditions. Steel reinforcement corrosion mass, ultimate pull-out force, corrosion rate, and bond slippage were chosen as characteristic parameters in the experiments, and scanning electron microscopy (SEM) analysis was used to explain the mechanism of action of freeze-thaw damage on corrosion. The results showed that, under identical corrosion conditions, the mass of steel reinforcement corrosion and corrosion rate increased by 39.6% and 39.7% when comparing 200 freeze-thaw cycles to 0 cycles, respectively. The ultimate pull-out force and bond slippage after 200 freeze-thaw cycles decreased by 73% and 31%, respectively, compared with 0 freeze-thaw cycles. In addition, SEM analysis indicated that microstructure damage caused by freeze-thaw cycles accelerated the corrosion reaction and decreased cementitious properties, leading to decreasing ultimate pull-out force and bond slippage. The effect of freeze-thaw cycles and steel reinforcement corrosion on the macro mechanical properties of concrete is not a simple superposition.

The Influence of Freeze–Thaw Cycles and Corrosion on Reinforced Concrete and the Relationship between the Evolutions of the Microstructure and Mechanical Properties

“…Because of seasonal temperature changes, nearly 100% of reinforced concrete structures in Northeast China are affected by freeze-thaw damage [8]. Compared with other reinforced concrete structures, hydraulic-reinforced concrete is more prone to freeze-thaw and SBC in areas where there are changes in water levels due to long-term contact with reservoirs [9], particularly in the case of concrete face slabs in rockfill dams [10]. FTCs lead to microscopic changes in the pore structure and ion transport properties of the concrete, producing microcracks that may accelerate the ion transport and the corrosion rate of the steel reinforcement.…”