Degradation of Mechanical Behavior of Corroded Prestressing Wires Subjected to High-Cycle Fatigue Loading

This paper presents an experimental investigation of the degradation of the mechanical behavior of corroded prestressing wires under high-cycle fatigue loading. To quantify the influence of corrosion degree, stress range, and loading cycles on the wires' mechanical properties, static tensile tests were performed on corroded prestressing wires with a predetermined fatigue-loading history. It was observed that after high-cycle fatigue loading, all corroded prestressing wires failed around corrosion pits as a result of uneven corrosion. The fracture surfaces no longer presented a cup-and-cone pattern, and the shear lip disappeared. The ductility of prestressing wires is very sensitive to high-cycle fatigue loading and corrosion. The postyield branch became dramatically shorter and even disappeared with increased corrosion degrees and loading cycles. With the increased degrees of corrosion and loading cycles, a significant reduction was found in the ultimate strength and ultimate strain of corroded prestressing wires, with little effect on effective elastic stiffness. The theoretical degradation models of the ultimate strength and ultimate strain were established for corroded prestressing wires subject to high-cycle fatigue loading and were found to be in good agreement with experimental results.