Abstract
A forensic investigation of unbonded post-tensioning (PT) tendons on a large structure revealed relatively advanced levels of strand corrosion within and inboard of anchors. In addition to concerns that this corrosion could result in wire and strand fractures and, hence, tendon failures, instances were observed where strand corrosion within anchors was sufficiently advanced that wires had disengaged from the wedges resulting in slip, contraction, and consequent load reduction in the strand. While such occurrences apparently transpired in conjunction with contiguous tendon removal activities, it is probable that the disengagements and resultant slippages were on the verge of occurring irrespective of these. Such slippage constitutes a potential failure mechanism for corroding PT systems that has not previously been reported.
