Title: Structural Responses of External Post-Tensioned Tendons to Increasing Localized Damage

Author(s): Jun Ki Lee

Publication: Structural Journal

Volume: 114

Issue: 5

Appears on pages(s): 1155-1166

Keywords: bridges; corrosion; damage; post-tensioning; stress redistribution; tendon

DOI: 10.14359/51689679

Date: 9/1/2017

Abstract:
This paper presents an experimental investigation of the structural effect of moderate to severe levels of localized damage in external post-tensioned tendons. Eight large-scale specimens with multiple seven-wire strands were fabricated, and the wires in the strands were consecutively fractured until a severe level of damage was identified using three controlled methods: accelerated galvanic corrosion, fatigue loading, and direct exposure to an acid solution. During this process, the structural effects induced by the applied damage were monitored based on visual inspection, acoustic sensors, transverse displacement, and vibration signals, depending on the experimental conditions. Experimental results showed that the behaviors of the damaged specimens were continuously governed by the residual tensile force, which was appreciably redistributed after wire fracture(s) in the strands, especially when the level of damage was moderate. As a result, the rate of decrement in the structural response became larger as the level of damage increased; however, they were not as sensitively influenced relative to the level of applied damage.