A novel test method for tendon re-anchorage in bonded post tensioned concrete using ESPI full field measurement

Abstract

In this paper, a novel test method is proposed to measure the re-anchorage of a ruptured tendon in bonded post-tensioned concrete. Full-field measurements on post-tensioned concrete prisms (500 x 100 x 100 mm) allow a large number of parameters to be considered. The full-field displacement on the concrete surface after the rupture was recorded using 3D Electronic Speckle Pattern Interferometry (ESPI), which is an optical contactless technique. The results in the paper also demonstrate the power of the ESPI measurements, which allow many more measurements to be made (in this study 256 x 51 point measurements of displacement in concrete prisms) in comparison to conventional techniques such as DEMEC and electrical resistance strain gauges. The comparison of the proposed test method results to the 3D non-linear finite element model predictions shows the strength of the proposed test method for studying the re-anchorage phenomenon of ruptured tendons.