Wire/Strand Slippage-A Potential Failure Mode for Post-Tensioning Tendons

摘要

A forensic investigation of unbonded, post-tensioning tendons on a large structure revealed relatively advanced levels of strand corrosion within and inboard of the end anchors. In addition to concerns that this corrosion could result in wire and strand fractures and tendon failures, instances were observed where strand corrosion within anchors was sufficiently advanced so that wires had disengaged from the wedges, resulting in slip, contraction, and consequent load reduction in the strand. Such slippage constitutes a potential failure mechanism for corroding post-tensioning systems that has not been previously reported.