Service life prediction of prestressed anchor cable exposed to a dry-wet cycling corrosion environment

The life of anchor cable will be shortened by corrosion in complex engineering environment, however at present there is no quantitative method available for predicting the service life of a prestressed anchor cable. Considering the key factor (dry-wet cycles) that causes the corrosion of anchor cables in an actual project, indoor dry-wet cycling corrosion test equipment and the electrolytic corrosion test device were developed in this work. Pseudo-environmental corrosion tests of the cables were performed. The variation of cable corrosion weight loss ratio with the number of dry wet cycles was revealed through the dry-wet cycling test, and based on this, a model for calculating the corrosion weight loss ratio was built. In addition, the change of the anchor force and breaking strength of the anchor cable with corrosion weight loss ratio was investigated through electrolytic corrosion tests and based on the findings an anchor force loss model and a breaking strength attenuation model were developed. On this basis, a life prediction method of anchor cable was established. The verification results of two engineering examples with anchor cable breakage show that the prediction life of this method is highly consistent with the actual life of the anchor cable, with a difference less than 1 year.