Experimental Study on Corrosion Development Model and Fatigue Performance of Strand Steel for Coastal Structures

In order to study the corrosion time-varying law and fatigue properties of high-strength steel strands used for marine environment structures, the accelerated corrosion test of steel strands was carried out by using a climate simulation chamber, and samples with different corrosion times were taken out for mass weighing, morphology observation, and fatigue testing. Steel strand specimens with different corrosion times (from 1 month to 14 years) for use in the real marine environment were developed in an indoor climate simulation test chamber. The average mass corrosion ratio curve of the steel strands in the marine environment and the changes in the corrosion pit size over time were obtained by performing data analysis based on weight and appearance. The time-varying rule of the fatigue life of coastal-structure steel strands was determined by conducting a fatigue test and fracture scanning electron microscopy (SEM) analysis of steel strands with different corrosion degrees. The results of the experimental study show that the mass corrosion rate and pit size of steel strands change with the service time as a piecewise function, fatigue performance changes with the service time is as an exponential function, and fatigue performance changes with the mass corrosion ratio are similar to a linear function. Furthermore, the corrosion pit has a significant impact on the fatigue life of the steel strand.