Simulation of self-centring fibre-reinforced concrete columns

Abstract

A self-centring, segmentally precast concrete column system is considered for bridges in highly seismic regions to mitigate the problem of residual displacements. Residual displacements in bridge columns can occur following severe earthquakes, and are a key indicator of post-earthquake functionality. The column system makes use of unbonded, post-tensioned steel tendons to provide self-centring to the columns, and incorporates a ductile, fibre-reinforced, cement-based composite to dissipate hysteretic energy and improve the damage tolerance of the columns. Large-scale experiments on the column system were conducted under cyclic loading, and are simulated using finite-element analysis. The goal of the simulations is to validate the ability of the finite-element models to capture the cyclic response of the columns with respect to global structural response (lateral load against displacement response) and the evolution of damage and failure modes of the columns. The models are found to perform well. The models are then used to assess column behaviour when changes are made to the ductile, fibre-reinforced material's mechanical properties, and to evaluate possible benefits that can be achieved.