Damage Detection in Strands of Post-Tensioned Tendon for Prestressed Concrete Bridges

Today, bridges play an important role in transportation networks, so that prestressed concrete bridges with post-tension tendon is one of the most common construction methods that have been prepared to meet the needs of infrastructure. These types of bridges are subject to various damages during operation, such as breakage in strands of tendons. Therefore, monitoring the status of their integrity during operation is of great importance. In this paper, a method based on axial strain changes in the wedge plate is used to identify strand breakage in post-tension tendons. Two wedge plate patterns, including 19- and 12-strand wedge plates, were modeled in ABAQUS software. Then, monitoring points were considered to identify the broken strand. Afterward, the performance of the damage detection framework based on axial strain changes was investigated by various wire breakage scenarios. The results show that the presence of breakage in strands of the tendon can be detected by observing distinct peaks at monitoring points. As the location of the damaged strand is closer to the monitoring points, the rate of axial strain changes will be more severe. Therefore, using the thresholds for each type of wedge plate, it is possible to identify the strand number that has been damaged in the post-tension tendon.