Background to multi-scale modelling of unbonded Post-Tensioned concrete structures

Abstract

Finite element analyses of unbonded Post-Tensioned (PT) concrete structures were carried out with a focus on the modelling of unbonded tendons embedded in the concrete. Two modelling approaches were studied to simulate unbonded conditions using the software package ABAQUS. The first approach was based on contact techniques, which reflect the true physical condition. The other approach used a multiple-spring system that provides more flexibility in modelling and robustness in convergence issues. First, this paper presents comparative results from those two approaches. Subsequently, more detailed analytical studies are described that adopt the spring system for modelling of unbonded PT concrete structures. The analytical results show a reasonably good agreement with experimental results and verify the effectiveness of the spring system approach that could be used for future studies of unbonded PT concrete structures.